Polyurethane elastomer, tseem hu ua polyurethane elastomer, yog cov khoom siv hluavtaws polymer uas muaj ntau pawg urethane ntawm cov saw tseem ceeb. Nws feem ntau yog tsim los ntawm oligomers xws li polyester, polyether thiab polyolefin. Nws yog tsim los ntawm gradual ntxiv thiab polymerization ntawm polyols, polyisocyanates thiab diols los yog diamine chain extenders. Nws yog cov khoom siv elastic ntawm cov roj hmab dav dav thiab cov yas, uas yog, nws muaj qhov elasticity siab ntawm cov roj hmab thiab lub zog siab ntawm cov yas. Nws muaj qhov loj elongation thiab ntau yam hardness; nws hnav tsis kam, biocompatibility thiab ntshav compatibility yog tshwj xeeb tshaj yog zoo. Nyob rau tib lub sijhawm, nws tseem muaj cov roj ua haujlwm zoo, kev cuam tshuam tsis zoo, tsis muaj qhov kub thiab txias, tiv thaiv hluav taws xob thiab thauj khoom tsis kam, rwb thaiv tsev kub, rwb thaiv tsev thiab lwm yam khoom. Yog li ntawd, daim ntawv thov teb ntawm polyurethane elastomers yog dav heev. Nws tau dhau los ua ib yam khoom tseem ceeb thiab tseem ceeb hauv kev lag luam hauv teb chaws thiab tib neeg lub neej.
Polyurethane elastomer muaj ntau yam khoom, uas zoo sib xws rau nws cov qauv, thiab nws cov qauv nyob ntawm ntau yam xws li reactants, lub sij hawm tshuaj tiv thaiv, qhov kub thiab txias, thiab txawm tias me me ntawm cov dej hauv cov ntsiab lus tuaj yeem ua rau polyurethane elastomers sib txawv loj hauv cov khoom siv kho tshuab. .
1. Txheej txheem cej luam ntawm Polyurethane Elastomers
Polyurethane elastomer, tseem hu ua polyurethane roj hmab, belongs rau cov roj hmab hluavtaws tshwj xeeb thiab yog ib hom elastic polymer uas muaj ntau pawg urethane (-NHCOO-) hauv cov saw tseem ceeb ntawm cov molecule. Nws yog ib yam khoom siv ntau block copolymer. . Polyurethane elastomers feem ntau yog npaj los ntawm polyaddition cov tshuaj tiv thaiv siv polymer polyols, isocyanates, chain extenders, cross-linking agents and a me me of auxiliary agents as raw material. Nyob rau hauv cov nqe lus ntawm cov qauv molecular, polyurethane elastomer (PUE) yog ib qho thaiv polymer, thiab nws cov saw molecular feem ntau yog tsim los ntawm ob feem. Ntawm qhov kub thiab txias, ib feem yog nyob rau hauv lub siab elasticity, hu ua mos ntu; Lub xeev crystalline hu ua ntu nyuaj. Feem ntau, qhov muag muag yog tsim los ntawm cov saw hlau ntev ntawm cov khoom siv polymer polyol, thiab cov ntu nyuaj yog tsim los ntawm isocyanate thiab saw extender. Cov ntu mos thiab ntu nyuaj yog hloov pauv los ua cov txheej txheem rov ua dua. Ntxiv rau pawg urethane, cov saw tseem ceeb ntawm polyurethane molecule kuj muaj cov pawg polar xws li ether, ester lossis urea pawg. Vim muaj coob tus ntawm cov pawg polar no, hydrogen bonds tuaj yeem tsim nyob rau hauv polyurethane molecule thiab nruab nrab ntawm cov molecules, thiab cov ntu mos thiab ntu tawv yog cov thermodynamically incompatible, uas induces tsim ntawm lub hard segment thiab mos. ntu microdomain thiab ua rau lub microscopic theem sib cais qauv. Linear polyurethanes tuaj yeem tsim kev sib txuas ntawm lub cev los ntawm kev sib txuas nrog hydrogen. Cov yam ntxwv ntawm cov qauv no ua rau polyurethane elastomers muaj kev hnav zoo heev thiab tawv, hu ua "cov roj hmab-resistant" [1], thiab vim tias muaj ntau ntau yam ntawm polyurethane raw cov ntaub ntawv, ntau yam thiab qhov sib piv ntawm cov ntaub ntawv raw tuaj yeem hloov kho rau cov khoom siv nrog. txawv kev ua tau zoo yam ntxwv. cov khoom, ua polyurethane elastomers dav siv nyob rau hauv lub teb chaws kev khwv nyiaj txiag. Txawm hais tias cov zis ntawm polyurethane elastomer tsis suav nrog ib feem me me ntawm cov khoom siv polyurethane, nws ntau yam thiab ntau yam kev siv tsis sib xws los ntawm lwm cov ntaub ntawv. Polyurethane elastomer muaj cov khoom zoo tshaj plaws, thiab nws cov modulus yog nruab nrab ntawm cov roj hmab thiab yas. Nws muaj cov yam ntxwv nram qab no: ①High lub zog thiab elasticity, muaj peev xwm tswj tau siab elasticity nyob rau hauv ntau yam hardness (Shore A10-Shore D75); ② Nyob rau tib lub zog, nws muaj peev xwm ua tau ntau dua li lwm cov elastomers; ③ Kev hnav zoo heev, nws hnav tsis kam yog 2-10 npaug ntawm cov roj hmab ntuj; ④ Kev qaug zog zoo thiab kev vibration tsis kam, haum rau kev siv ntau zaus deflection; ⑤ Kev tiv thaiv siab; ⑥ Aromatic polyurethane kuj muaj hluav taws xob zoo heev, oxygen tsis kam thiab ozone kuj; ⑦ Cov roj zoo heev thiab tshuaj lom neeg ua haujlwm; ⑧ Feem ntau, qhov yuav tsum tau qis hardness tuaj yeem ua tiav yam tsis muaj plasticizer, yog li tsis muaj teeb meem tshwm sim los ntawm plasticizer tsiv teb tsaws; ⑨ Moulding thiab nqi ua haujlwm tsawg; ⑩ Ordinary polyurethane tsis tuaj yeem siv siab tshaj 100 degree, tab sis cov qauv tuaj yeem tiv taus qhov kub ntawm 140 degree. Raws li ib txwm muaj, piv nrog cov khoom siv hlau, cov khoom siv polyurethane elastomer muaj qhov zoo ntawm lub teeb yuag, tsis muaj zog, tsis muaj suab nrov, tsis tshua muaj nqi ua haujlwm thiab corrosion kuj; piv nrog roj hmab, polyurethane elastomers muaj hnav tsis kam, txiav tsis kam, tsis kam ua kua muag, siab load-bearing, pourable, pottable, pob tshab los yog translucent, ozone kuj, hardness ntau yam thiab lwm yam zoo; piv nrog cov yas, polyurethane elastomers muaj qhov zoo ntawm tsis muaj brittleness, elastic nco, hnav tsis kam, thiab lwm yam. Muaj ntau txoj kev ua rau polyester elastomers, cov technologies tshiab thiab ntau yam tshiab tau tshwm sim tas li, thiab daim ntawv thov kev cia siab yuav nthuav dav heev [2] .
2. Kev siv tshuab ntawm polyurethane elastomer
Hauv chav kuaj, polyurethane elastomers feem ntau yog tsim los ntawm tes-casting prepolymer txoj kev, nrog rau ib-kauj ruam txoj kev, prepolymer method thiab semi-prepolymer method.
Txoj kev ib-kauj ruam yog ntxiv cov diisocyanate, polyol, catalyst thiab lwm yam auxiliary agents nyob rau hauv cov mis ib zaug, thiab ncuav nws mus rau hauv pwm tom qab high-speed stirring los npaj cov khoom polyurethane elastomer. Txawm hais tias cov khoom tau txais los ntawm cov txheej txheem ib-kauj ruam muaj kev ua haujlwm tsis zoo thiab rov ua dua, thiab tuaj yeem ua kom paub ntau cov pa npuas rau hauv cov tshuaj tiv thaiv, kom muaj ntau cov khoom hauv cov khoom, cov txheej txheem ntawm txoj kev no yog. yooj yim, txuag hluav taws xob, thiab txo cov nqi, yog li txoj kev no feem ntau yog siv hauv kev lag luam foaming, tab sis tsis tshua muaj siv hauv kev tsim cov cam khwb cia polyurethane elastomers [3]. Tam sim no, nrog kev tshwm sim ntawm qee cov txheej txheem molding tshiab xws li tshuaj tiv thaiv kev txhaj tshuaj molding (RIM) thev naus laus zis, txoj kev ib-kauj ruam kuj tau tsim kho sai dua.
Lub polyurethane elastomer npaj los ntawm txoj kev prepolymer muab faib ua ob kauj ruam, yog li nws tseem hu ua ob-kauj ruam txoj kev. Ua ntej, oligomer cawv thiab ntau tshaj polyisocyanate yog reacted los ua ib tug prepolymer nrog ib tug NCO pab pawg neeg nyob rau hauv lub kawg pab pawg neeg, thiab ces cov polymer yog reacted nrog ib tug saw extender thaum lub sij hawm casting los npaj ib tug polyurethane elastomer. Txoj kev no feem ntau yog siv los tsim cov polyurethane elasticity. Qhov tsis zoo yog tias cov prepolymer yog rhiab rau qhov kub thiab txias, yuav tsum muaj cov khoom siv siab thaum lub sij hawm casting, thiab muaj cov txheej txheem ntev. Qhov txawv ntawm txoj kev semi-prepolymer thiab txoj kev prepolymer yog qee qhov polyester polyols lossis polyether polyols, saw extenders, chemical additives, thiab lwm yam yog ntxiv rau prepolymer hauv daim ntawv sib tov. Uas yog hais tias, oligomer polyol nyob rau hauv cov mis yog muab faib ua feem, ib feem yog reacted nrog ntau tshaj diisocyanate rau synthesize prepolymer, thiab lwm qhov yog tov nrog saw extender thiab ntxiv thaum txhaj. Qhov loj feem ntawm NCO dawb nyob rau hauv lub resulting prepolymer yog kuj siab, feem ntau yog 0.12-0.15 (12 feem pua - feem pua), yog li no prepolymer feem ntau hu ua "quasi-prepolymer". Cov yam ntxwv ntawm cov txheej txheem semi-prepolymer: ① Lub viscosity ntawm prepolymer tivthaiv yog tsawg, thiab nws tuaj yeem hloov kho kom zoo ib yam li cov viscosity ntawm cov khoom sib xyaw ntawm tus neeg sawv cev kho; ② Qhov piv kuj tseem nyob ze (uas yog, qhov sib xyaw loj sib piv tuaj yeem yog 1: 1). Qhov no tsis tsuas yog txhim kho kev sib xyaw ua ke, tab sis kuj txhim kho qee yam khoom ntawm elasticity. Txoj kev no yog ib qho yooj yim kom paub txog kev lag luam: ntawm peb txoj kev saum toj no, feem ntau hais lus, polyurethane elastomer npaj los ntawm cov txheej txheem prepolymer muaj qhov ua tau zoo tshaj plaws, thiab cov txheej txheem ib-kauj ruam muaj kev ua haujlwm tsis zoo. Qhov no yog vim hais tias nyob rau hauv ib-kauj ruam txoj kev, lub polymerization thiab saw extension cov tshuaj tiv thaiv yog nqa tawm nyob rau tib lub sij hawm. Nyob rau hauv lub tom ntej no theem ntawm cov tshuaj tiv thaiv, vim lub ntse nce nyob rau hauv lub viscosity ntawm lub system, cov kev ua ntawm cov molecular saw yog tswj los ntawm diffusion cov tshuaj tiv thaiv, cov tshuaj tiv thaiv tsis tiav, thiab lub molecular hnyav ntawm cov polyurethane elastomer tau yog kuj. me me. Cov qauv tsis sib xws, uas cuam tshuam rau kev ua haujlwm ntawm polyurethane elastomer. Nyob rau hauv tus txheej txheem ntawm txoj kev prepolymer, cov tshuaj tiv thaiv ntawm polyurethane prepolymer thiab cov tshuaj tiv thaiv ntawm polyurethane prepolymer thiab cov saw extender yog ua los ntawm cov kauj ruam, thiab lawv yog tag nrho cov tshuaj tiv thaiv. Cov tshuaj tiv thaiv zoo heev, thiab cov tau txais polyurethane elastic Cov khoom hnyav molecular yog qhov loj thiab cov qauv zoo ib yam, uas yog qhov tsim nyog rau kev tsim cov hydrogen bonds ntawm macromolecules, yog li txhim kho kev ua haujlwm ntawm polyurethane elastomer. Cov khoom ntawm polyurethane elastomer npaj los ntawm txoj kev semi-prepolymer yog nyob nruab nrab ntawm txoj kev prepolymer thiab ib-kauj ruam txoj kev, thiab cov tshuaj tiv thaiv kub yog tsawg, uas yog haum rau industrial ntau lawm. Daim ntawv no tham txog kev sib raug zoo ntawm cov qauv thiab cov khoom ntawm polyurethane elastomers, tag nrho cov uas yog synthesized los ntawm txoj kev prepolymer.
3. Cov qauv thiab cov khoom ntawm polyurethane elastomers
Cov khoom siv ntawm polyurethane elastomers ncaj qha cuam tshuam rau cov qauv sab hauv ntawm polyurethane elastomers, thiab lawv cov microstructure thiab morphology muaj kev cuam tshuam loj heev los ntawm kev sib cuam tshuam ntawm pawg polar, xws li hom, qauv thiab morphology ntawm mos thiab tawv ntu. Mechanical zog thiab kub tsis kam ntawm polyurethane elastomers. Nyob rau hauv xyoo tas los no, tib neeg tau pib kawm txog kev sib raug zoo ntawm cov khoom siv kho tshuab ntawm polyurethane elastomers thiab lawv cov qauv sib sau ua ke thiab microstructures.
ib. Microphase cais qauv ntawm polyurethane elastomer
Cov khoom ntawm polyurethane feem ntau cuam tshuam los ntawm cov qauv morphological ntawm macromolecular saw. Qhov tshwj xeeb yooj thiab lub cev zoo ntawm polyurethane tuaj yeem piav qhia los ntawm ob-theem morphology. Cov degree ntawm microphase sib cais thiab ob-theem qauv ntawm cov mos thiab tawv ntu hauv polyurethane elastomers yog qhov tseem ceeb rau lawv cov kev ua tau zoo. Kev sib cais theem nruab nrab yog qhov zoo los txhim kho cov khoom ntawm cov polymer. Cov txheej txheem sib cais ntawm microphase kev sib cais yog qhov sib txawv ntawm cov polarity ntawm cov ntu nyuaj thiab cov ntu mos thiab cov crystallinity ntawm cov ntu nyuaj nws tus kheej ua rau lawv cov thermodynamic incompatibility (immiscibility) thiab ib qho kev nyiam rau cov theem sib cais, yog li cov ntu nyuaj yog yooj yim. kom Aggregate ua ke los tsim cov thawj, uas yog dispersed nyob rau hauv lub nruam theem tsim los ntawm cov mos segments. Cov txheej txheem ntawm kev sib cais microphase tiag tiag yog cov txheej txheem ntawm kev sib cais thiab sib sau ua ke lossis crystallization ntawm cov ntu nyuaj hauv elastomer los ntawm copolymer system.
Qhov tshwm sim ntawm polyurethane micro-theem sib cais yog thawj zaug los ntawm American kws tshawb fawb Cooper. Tom qab ntawd, ntau txoj haujlwm tshawb fawb tau ua tiav ntawm cov qauv ntawm polyurethane [4]. Kev tshawb fawb ntawm cov qauv sib sau ua ke ntawm polyurethane kuj tau ua tiav, tsim cov qauv ua tiav. Lub microphase qauv txoj kev xav ntawm [5] system: nyob rau hauv lub block polyurethane system, microphase sib cais ntawm cov ntu tawv thiab cov mos ntu yog induced los ntawm cov thermodynamic incompatibility ntawm ntu thiab cov mos mos. Lub zog txaus nyiam ntawm cov ntu nruab nrab ntawm cov ntu nyuaj yog ntau dua li ntawm cov ntu nruab nrab ntawm cov ntu mos. Cov ntu nyuaj yog insoluble nyob rau hauv lub mos ntu ntu, tab sis tau muab faib rau hauv nws, tsim ib qho kev sib txuas ntawm microphase qauv (sea-island qauv). Nws plays lub cev sib txuas thiab txhawb nqa lub luag haujlwm hauv qhov muag muag. Hauv cov txheej txheem ntawm kev sib cais microphase, kev sib txuas ntxiv ntawm cov ntu nyuaj yuav pab txhawb kev sib cais ntawm cov ntu nyuaj ntawm lub cev thiab sib sau los yog crystallize, txhawb kev sib cais microphase. Tau kawg, muaj qee qhov kev sib raug zoo ntawm cov theem yas thiab cov roj hmab theem, thiab cov theem ntawm cov yas micro-domains thiab cov roj hmab micro-domains yog sib xyaw ua ke los ntawm theem ntws. Nyob rau tib lub sijhawm, lwm cov qauv hais txog kev sib cais microphase kuj tau npaj tseg, xws li Seymour [6] thiab lwm tus tau hais tias cov ntu nyuaj thiab ntu ntu ntu uas txhawb nqa cov cheeb tsam tsim kom muaj kev sib txuas txuas txuas txuas ntxiv nrog rau ib leeg. Paik Sung thiab Schneide [7] tau npaj cov qauv kev sib cais ntawm microphase muaj tseeb: qhov degree ntawm microphase sib cais hauv urethane yog qhov tsis zoo, tsis yog microphase coexistence nkaus xwb, tab sis suav nrog cov khoom sib xyaw ua ke. Muaj kev sib xyaw ntawm ntu hauv micro-domain, uas muaj qee qhov kev cuam tshuam ntawm morphology thiab mechanical zog ntawm cov khoom. Cov ntu muag muag muaj cov ntu tawv, uas tuaj yeem ua rau muaj kev hloov pauv hauv iav hloov qhov kub ntawm qhov muag muag. Brightly txhim kho, nqaim ntau yam ntawm cov ntaub ntawv siv nyob rau hauv tsis tshua muaj kub ib puag ncig. Kev suav nrog cov ntu ntu hauv cov ntu ntu ntu tuaj yeem txo cov iav hloov pauv kub ntawm cov ntu ntu ntu, yog li txo cov cua sov ntawm cov khoom siv.
b. Hydrogen Bonding Cwj Pwm ntawm Polyurethane Elastomers
Hydrogen bonds muaj nyob nruab nrab ntawm cov pab pawg uas muaj nitrogen atoms thiab oxygen atoms uas muaj zog electronegativity thiab pab pawg muaj hydrogen atoms. Lub zog cohesive ntawm cov pab pawg muaj feem xyuam nrog qhov loj ntawm lub zog cohesive ntawm cov pab pawg. Muaj zog, hydrogen bonds feem ntau muaj nyob nruab nrab ntawm ntu. Raws li cov lus ceeb toom, feem ntau ntawm cov imine pawg nyob rau hauv ntau pawg ntawm polyurethane macromolecules tuaj yeem tsim hydrogen bonds, thiab feem ntau ntawm lawv yog tsim los ntawm cov pab pawg imine thiab carbonyl pawg hauv ntu nyuaj, thiab ib feem me me yog tsim nrog ether oxygen. nyob rau hauv lub mos ntu. pawg los yog ester carbonyl tsim. Piv nrog rau lub zog sib txuas ntawm cov tshuaj intramolecular, lub zog sib txuas ntawm hydrogen yog me dua. Txawm li cas los xij, qhov muaj ntau ntawm hydrogen bonds hauv polar polymers kuj yog ib qho tseem ceeb cuam tshuam rau kev ua haujlwm. Hydrogen bonds yog reversible. Thaum qhov kub thiab txias, qhov sib ze ntawm cov ntu sib deev txhawb kev tsim cov hydrogen bonds: ntawm qhov kub siab dua, cov ntu tau txais lub zog thiab ua kom sov, qhov kev ncua deb ntawm ntu thiab molecules nce, thiab cov hydrogen bonds tsis muaj zog lossis txawm ploj mus. Hydrogen bonds ua lub luag haujlwm ntawm kev sib txuas ntawm lub cev, uas tuaj yeem ua rau lub cev polyurethane muaj zog dua, ua kom tsis muaj zog, hnyav tsis kam thiab me me tensile mus tas li deformation. Qhov ntau hydrogen bonds, lub zog muaj zog ntawm cov khoom siv hluav taws xob ntau dua thiab ntau dua lub zog ntawm cov khoom. Tus nqi ntawm hydrogen bonds ncaj qha cuam tshuam rau qib ntawm microphase sib txawv ntawm lub cev [8].
c. Crystallinity
Cov kab hluav taws xob polyurethane nrog cov qauv tsis tu ncua, ntau pawg polar thiab nruj, ntau qhov sib xyaw hydrogen bonds, thiab crystallinity zoo, tau txhim kho qee yam khoom ntawm cov khoom siv polyurethane, xws li lub zog thiab hnyav ua haujlwm. Lub hardness, lub zog thiab softening taw tes ntawm polyurethane cov ntaub ntawv nce nrog cov crystallinity nce, thaum elongation thiab solubility txo raws li. Rau qee qhov kev siv, xws li ib qho khoom siv thermoplastic polyurethane adhesives, ceev crystallization yuav tsum tau txais thawj zaug tack. Qee cov thermoplastic polyurethane elastomers tso tawm sai dua vim lawv cov crystallinity siab. Crystalline polymers feem ntau ua opaque vim anisotropy ntawm refracted lub teeb. Yog hais tias ib tug me me ntawm ceg los yog pendant pawg tau nkag mus rau hauv crystalline linear polyurethane macromolecules, crystallinity ntawm cov khoom txo. Thaum lub crosslinking ceev nce mus rau ib qho twg, qhov muag muag poob nws cov crystallinity. Thaum cov khoom siv stretched, lub tensile kev nyuaj siab ua rau cov saw molecular ntawm cov mos ntu taw qhia thiab qhov kev ua kom zoo dua qub, cov crystallinity ntawm polyurethane elastomer zoo dua, thiab lub zog ntawm cov khoom siv tau zoo dua qub. Qhov muaj zog ntawm cov polarity ntawm cov ntu nyuaj, qhov zoo dua rau kev txhim kho lub zog lattice ntawm cov khoom siv polyurethane tom qab crystallization. Rau polyether polyurethane, nrog kev nce ntawm cov ntsiab lus nyuaj, cov pawg polar nce, lub zog intermolecular ntawm cov ntu nyuaj nce, qib ntawm microphase sib cais nce, qhov nyuaj ntu microdomain maj mam ua crystallization, thiab crystallinity nce nrog cov ntu nyuaj. cov ntsiab lus. Maj mam nce lub zog ntawm cov khoom.
d. Kev cuam tshuam ntawm cov qauv mos ntawm cov khoom ntawm polyurethane elastomer
Oligomeric polyols xws li polyethers thiab polyesters ua rau cov ntu muag muag. Cov ntu muag muag rau feem ntau ntawm cov polyurethane, thiab cov khoom ntawm polyurethane npaj los ntawm cov oligomer polyols thiab diisocyanates sib txawv. Qhov saj zawg zog (mos) ntu ntawm polyurethane elastomers feem ntau cuam tshuam rau cov khoom elastic ntawm cov khoom thiab ua rau nws qhov kub thiab txias thiab tensile zog. Yog li ntawd, Tg parameter ntawm lub mos ntu yog qhov tseem ceeb heev, thiab qhov thib ob, lub crystallinity, melting point thiab strain-induced crystallization kuj yog yam tseem ceeb uas cuam tshuam rau nws cov khoom siv kho qhov kawg. Polyurethane elastomers thiab foams ua los ntawm polyester nrog muaj zog polarity raws li cov khoom muag muag muaj cov khoom zoo dua qub. Vim hais tias cov polyurethane ua los ntawm polyester polyol muaj ib tug loj polar ester pawg, tsis tsuas yog hydrogen bonds yuav tsim nyob rau hauv lub hard segments, tab sis kuj cov polar pawg ntawm lub mos ntu tuaj yeem cuam tshuam nrog cov ntu nyuaj. Cov pawg polar tsim cov ntawv cog lus hydrogen, kom cov ntu ntu ntu tuaj yeem faib ua ntau yam sib xws hauv ntu ntu ntu, uas ua raws li qhov sib txuas sib txuas. Qee cov polyester polyols tuaj yeem tsim cov ntu mos crystallization ntawm chav tsev kub, uas cuam tshuam rau cov khoom ntawm polyurethane. Lub zog, roj tsis kam thiab thermal oxidative aging ntawm polyester polyurethane cov ntaub ntawv yog siab dua cov PPG polyether polyurethane cov ntaub ntawv, tab sis cov hydrolysis tsis kam yog phem dua li ntawm polyether hom. Polytetrahydrofuran (PTMG) polyurethane yog ib qho yooj yim los tsim crystals vim nws cov qauv molecular saw, thiab nws lub zog yog piv rau cov polyester polyurethane. Feem ntau hais lus, ether pawg ntawm cov mos mos ntawm polyether polyurethane yog ib qho yooj yim rau tig sab hauv, muaj kev ywj pheej zoo, thiab muaj kev ua haujlwm kub tsis zoo, thiab tsis muaj ester pawg uas yooj yim rau hydrolyze hauv polyether polyol saw, thiab nws. tiv thaiv hydrolysis Zoo dua polyester polyurethane. Cov pa roj carbon ntawm ether daim ntawv cog lus ntawm polyether mos ntu yog yooj yim oxidized los tsim peroxide radicals, ua rau muaj kev cuam tshuam oxidative degradation. Cov polyurethane nrog polybutadiene molecular saw raws li cov ntu muag muag muaj qhov tsis muaj zog polarity, tsis zoo sib xws ntawm ntu mos thiab tawv, thiab lub zog elastomer tsis zoo. Vim yog steric hindrance, lub mos ntu uas muaj cov saw hlau muaj zog hydrogen bonds, tsis muaj crystallinity, thiab lub zog yog phem dua li ntawm tib lub mos ntu tseem ceeb saw tsis muaj sab pawg polyurethane. Qhov hnyav molecular ntawm ntu mos muaj qhov cuam tshuam rau cov khoom siv kho tshuab ntawm polyurethane. Feem ntau hais lus, piv txwv tias qhov hnyav molecular ntawm polyurethane yog tib yam, lub zog ntawm cov khoom siv polyurethane txo qis nrog qhov nce ntawm qhov hnyav molecular ntawm qhov muag; Yog hais tias qhov muag muag yog cov saw hlau polyester, lub zog ntawm cov khoom siv polymer txo qis nrog qhov nce ntawm qhov hnyav molecular ntawm polyester diol; Yog tias qhov muag muag yog cov saw hlau polyether, lub zog ntawm cov khoom siv polymer txo qis nrog qhov nce ntawm qhov hnyav molecular ntawm polyether glycol, tab sis qhov elongation nce. Qhov no yog vim lub siab polarity ntawm ester mos ntu thiab lub zog loj intermolecular, uas tuaj yeem cuam tshuam qhov txo qis ntawm lub zog ntawm cov khoom siv polyurethane vim qhov nce hauv qhov hnyav molecular thiab nce hauv cov ntsiab lus muag muag. Cov ntu mos ntawm polyether tsis muaj zog hauv polarity. Yog tias qhov hnyav molecular nce, cov ntsiab lus ntawm cov ntu nyuaj hauv cov khoom sib txuam polyurethane txo qis, ua rau txo qis ntawm lub zog ntawm cov khoom. Zhu Jinhua et al. [9] synthesized ib tug series ntawm polyurethane thaiv copolymers thiab graft copolymers uas muaj nyias ntu, thiab sim lawv dynamic mechanical zog. Cov txiaj ntsig tau pom tias kev sib raug zoo ntawm polyurethane copolymer thiab cov saw hlau ntawm macromolecules Cov qauv muaj feem xyuam, muaj cov saw hlau muaj txiaj ntsig zoo rau kev sib raug zoo thiab cov khoom damping ntawm polyurethane block copolymer. Feem ntau, cov nyhuv ntawm cov mos mos molecular hnyav ntawm qhov tsis kam thiab thermal aging zog ntawm polyurethane elastomers tsis tseem ceeb. Lub crystallinity ntawm cov mos mos muaj kev pab zoo rau lub crystallinity ntawm linear polyurethane. Feem ntau hais lus, crystallinity yog qhov zoo los ua kom lub zog ntawm polyurethane. Tab sis qee zaum crystallization txo qis qhov kub thiab txias ntawm cov khoom siv, thiab crystalline polymers feem ntau opaque. Txhawm rau kom tsis txhob muaj crystallization, kev ncaj ncees ntawm cov molecule yuav raug txo kom tsawg, xws li siv cov copolyester los yog copolyether polyol, los yog mixed polyol, mix chain extender, thiab lwm yam.
e. Kev cuam tshuam ntawm ntu ntu ntawm cov khoom ntawm polyurethane elastomer
Cov qauv ntu nyuaj yog ib qho ntawm cov ntsiab lus tseem ceeb cuam tshuam rau lub tshav kub tsis kam ntawm polyurethane elastomers. Cov qauv ntawm cov diisocyanate thiab cov saw txuas ntxiv uas ua rau cov ntu polyurethane elastomer sib txawv, uas tseem cuam tshuam rau cov cua sov. Cov ntu nyuaj ntawm cov khoom siv polyurethane yog tsim los ntawm polyisocyanate thiab saw extender. Nws muaj cov pawg polar muaj zog xws li pawg urethane, pawg aryl thiab hloov urea pawg. Feem ntau, ntu ntu tsim los ntawm cov tshuaj tsw qab isocyanate tsis yooj yim hloov, thiab ncab ntawm chav tsev kub. qws-shaped. Cov ntu tawv feem ntau cuam tshuam rau qhov kub siab ntawm polyurethane, xws li softening, melting kub. Feem ntau siv diisocyanates yog TDI, MDI, IPDI, PPDI, NDI, thiab lwm yam, feem ntau siv cawv yog ethylene glycol, -butanediol, hexanediol, thiab lwm yam, thiab feem ntau siv amines yog MOCA, EDA, DETDA, thiab lwm yam. raug xaiv raws li qhov xav tau ntawm cov khoom siv hluav taws xob ntawm cov polymer, xws li kev siv siab tshaj plaws, huab cua tsis kam, solubility, thiab lwm yam, thiab nws txoj kev lag luam yuav tsum tau txiav txim siab. Cov qauv diisocyanate sib txawv tuaj yeem cuam tshuam rau qhov tsis tu ncua ntawm cov ntu nyuaj thiab tsim cov hydrogen bonds, yog li muaj kev cuam tshuam ntau dua rau lub zog ntawm elastomer. Feem ntau hais lus, cov isocyanate uas muaj cov nplhaib uas muaj ntxhiab ua rau cov ntu nyuaj muaj zog dua thiab sib zog, uas feem ntau ua rau lub zog ntawm elastomer.
Cov ntu ntu uas muaj urea pawg muaj li ntawm diisocyanate thiab diamine chain extender yog ib qho yooj yim heev los tsim cov yas micro-domain vim muaj kev sib koom ua ke loj ntawm urea pawg, thiab cov polyurethane tsim los ntawm ntu ntu no yog qhov ua rau micro-theem. kev sib cais. Feem ntau hais lus, qhov siab dua qhov nruj ntawm ntu ntu uas tsim los ntawm polyurethane, qhov yooj yim ntawm kev sib cais microphase tshwm sim. Nyob rau hauv lub polyurethane, qhov siab dua cov ntsiab lus ntawm cov ntu ntu, qhov ntau dua qhov kev sib cais microphase tshwm sim.
Cov saw extender muaj feem xyuam rau qhov nyuaj ntu qauv ntawm polyurethane elastomer thiab muaj kev cuam tshuam zoo rau kev ua haujlwm ntawm elastomer. Piv nrog rau cov saw txuas txuas ntxiv ntawm polyurethane ntawm aliphatic diol, cov saw txuas txuas ntxiv polyurethane uas muaj cov nplhaib uas muaj ntxhiab diamine muaj zog dua, vim tias cov saw hlau txuas ntxiv tuaj yeem tsim cov urea daim ntawv cog lus, thiab cov polarity ntawm urea daim ntawv cog lus siab dua li ntawm daim ntawv cog lus urethane. . Ntxiv mus, qhov sib txawv ntawm solubility tsis nyob nruab nrab ntawm qhov nyuaj ntu ntawm urea daim ntawv cog lus thiab lub mos ntu ntawm polyether yog loj, yog li lub nyuaj ntu ntawm polyurea thiab lub mos ntu ntawm polyether muaj ntau dua thermodynamic incompatibility, uas ua rau polyurethaneurea muaj zoo microphase sib cais. [10], yog li diamine chain-extended polyurethane muaj zog dua txhua yam, modulus, viscoelasticity, tshav kub tsis kam, thiab kev ua haujlwm kub zoo dua li diol chain-extended polyurethane. Casting polyurethane elastomers feem ntau siv cov tshuaj tsw qab diamines ua cov saw txuas ntxiv vim tias cov polyurethane elastomers npaj tau los ntawm muaj cov khoom zoo. Xu Guangjie et al. [11] qhia tias carboxyl ester polyols tau npaj los ntawm reacting maleic anhydride nrog polyols, thiab tom qab ntawd reacting nrog lwm cov monomers xws li TDI -80, cross-linking agents thiab chain extenders los npaj carboxyl-muaj polyols. Polyurethane prepolymer tau dispersed nyob rau hauv ib tug aqueous tov ntawm triethanolamine los ua dej-raws li polyurethane, thiab cov cawv ntawm hom thiab tus nqi ntawm cov saw extender ntawm kev ua tau zoo ntawm cov cob tau kawm, thiab nws tau pom tias amine chain extender tau zoo dua. hydroxyl saw extender Nws yog qhov zoo los txhim kho cov khoom siv ntawm cov cob. Kev siv bisphenol A ua cov saw txuas ntxiv tuaj yeem tsis tsuas yog txhim kho cov khoom siv kho tshuab ntawm cov cob, tab sis kuj ua rau cov iav hloov pauv kub ntawm cov resin, nthuav dav qhov dav ntawm sab hauv kev sib txhuam, thiab txhim kho qhov kub thiab txias ntawm cov resin hauv lub xeev tawv [ 12]. Cov qauv ntawm diamine chain extender siv nyob rau hauv polyurethane urea ncaj qha cuam tshuam rau hydrogen bonding, crystallization, thiab microphase qauv sib cais nyob rau hauv cov khoom, thiab loj txiav txim siab qhov kev ua tau zoo ntawm cov khoom [13]. Nrog rau qhov nce ntawm cov ntsiab lus nyuaj, lub zog tensile thiab hardness ntawm cov khoom siv polyurethane maj mam nce, thiab elongation ntawm kev tawg poob qis. Qhov no yog vim hais tias muaj microphase sib cais ntawm cov theem nrog ib tug tej yam degree ntawm crystallinity tsim los ntawm lub hard segment thiab lub amorphous theem tsim los ntawm cov mos ntu, thiab lub crystalline cheeb tsam ntawm lub nyuaj segment ua raws li ib tug zoo cross-linking point. Nws kuj plays lub luag hauj lwm zoo ib yam li muab tub lim rau lub amorphous cheeb tsam ntawm lub mos ntu. Thaum cov ntsiab lus nce ntxiv, cov txiaj ntsig kev txhawb zog thiab cov txiaj ntsig crosslinking zoo ntawm cov ntu nyuaj hauv ntu ntu yog txhim kho, uas txhawb kev nce ntawm cov khoom siv zog.
f. Kev cuam tshuam ntawm crosslinking ntawm cov khoom ntawm polyurethane elastomers
Qhov nruab nrab intramolecular crosslinking tuaj yeem ua rau kom muaj zog, softening kub thiab elastic modulus ntawm polyurethane cov ntaub ntawv, thiab txo elongation ntawm tawg, mus tas li deformation thiab o nyob rau hauv cov kuab tshuaj. Rau polyurethane elastomers, kev sib txuas kom zoo tuaj yeem tsim cov ntaub ntawv nrog cov khoom siv zoo heev, siab hardness, elasticity, thiab zoo heev hnav tsis kam, roj kuj, ozone kuj thiab kub tsis kam. Txawm li cas los xij, yog tias crosslinking ntau dhau, cov khoom xws li tensile lub zog thiab elongation tuaj yeem txo. Hauv block polyurethane elastomers, tshuaj crosslinking tuaj yeem muab faib ua ob pawg: (1) kev siv cov saw hlau txuas ntxiv (xws li TMP) los tsim cov qauv sib txuas; (2) kev siv cov isocyanate ntau dhau los ua kom muaj cov dicondensate Urea (ntawm urea pawg) lossis allophanate (ntawm urethane pawg) crosslinking. Crosslinking muaj qhov cuam tshuam loj rau qib ntawm hydrogen bonding, thiab tsim cov crosslinks zoo heev txo cov qib ntawm hydrogen bonding ntawm cov khoom, tab sis cov tshuaj crosslinking muaj thermal stability zoo dua li lub cev crosslinking los ntawm hydrogen bonding. Thaum cov teebmeem ntawm kev sib txuas ntawm cov tshuaj sib txuas ntawm cov morphology, cov khoom siv kho tshuab thiab cov khoom siv thermal ntawm polyurethane urea elastomers tau kawm los ntawm FT-IR thiab DSC, nws tau pom tias polyurethane urea elastomers nrog cov sib txuas sib txuas sib txawv muaj cov qauv sib txawv. Raws li qhov ceev nce, qhov degree ntawm microphase sib xyaw ntawm elastomer nce, cov iav hloov pauv kub ntawm qhov muag muag nce ntxiv, thiab 300 feem pua tensile lub zog ntawm lub elastomer maj mam nce, thaum lub elongation ntawm so maj mam txo. Thaum, cov khoom siv kho tshuab (lub zog tensile thiab lub zog tsim kua muag) ntawm elastomer ncav cuag qhov siab tshaj plaws.
4. Kev siv ntawm Polyurethane Elastomers
ib. Siv rau hauv kev npaj thee, mining, metallurgy thiab lwm yam lag luam
Polyurethane elastomers yog cov khoom siv tsis yog xim hlau uas ua tau raws li cov kev cai ntawm cov mines thiab tuaj yeem hloov qee cov ntaub ntawv hlau. Polyurethane elastomer khoom rau roob muaj sieve daim hlau, elastomer linings, conveyor siv, thiab lwm yam. Polyurethane roj hmab sieves muaj xws li so sieves, nro sieves, slotted sieves, thiab lwm yam. Polyurethane roj hmab npo phaj muaj cov yam ntxwv ntawm zoo heev hnav tsis kam, dej tsis kam, roj kuj, kev co nqus nqus thiab suab nrov txo, siab zog, muaj zog sib txuas nrog cov hlau ncej, tsawg. suab nrov, ua haujlwm zoo rau tus kheej, ua kom lub nra ntawm lub vijtsam tshuab, txuag lub zog noj, thiab ua kom lub sijhawm ntev ntawm lub vijtsam. Tshuab lub neej, kev tshuaj ntsuam xyuas zoo. Ntau cov khoom siv mining xws li shakers, tshwj xeeb concentrators, flotation machines, concentrators, kauv troughs, pulverizers, concentrators, kav, thiab lub luj tshib, tiv tauj cov ntaub ntawv xws li gravel, thiab yuav tsum tau hnav-resistant linings; mining monorail cranes Cov tub ntxhais hlau urethane tsav log, nplaim hluav taws kub thiab antistatic polyurethane conveyor siv, khoom siv cable TPU sheath, plua plav nplhaib, kev poob siab, thiab lwm yam., polyurethane elastomer yog cov khoom nyiam.
b. Polyurethane roj hmab cov menyuam
Polyurethane roj hmab cov menyuam yog ib yam ntawm cov khoom siv roj hmab polyurethane nrog kev ua tau zoo, uas feem ntau yog ua los ntawm cov hlau los yog hlau npog nrog ib txheej ntawm polyurethane elastomer los ntawm txheej txheem casting. Raws li kev siv, muaj: hulling roj hmab rollers rau kev ua qoob loo, extrusion roj hmab rollers thiab pulping roj hmab rollers nyob rau hauv daim ntawv kev lag luam, hlau kos duab rollers, drafting rollers thiab txiav chais nyob rau hauv lub textile kev lag luam, ntoo, iav thiab ntim Transmission bearing rubber rollers siv nyob rau hauv kev lag luam, ntau yam roj hmab rollers rau luam ntawv thiab dyeing machinery, me me roj hmab rollers rau ntau yam twj paj nruag, kis tau tus mob roj hmab rollers rau conveying tshuab, luam ntawv roj hmab rollers, hlau txias dov kis tau tus mob roj hmab rollers, hlau hlau phaj xim txheej rollers, thiab lwm yam. txheej ntawm cov roj hmab rollers tuaj yeem ua los ntawm polyurethane elastomer. Feem ntau ntawm cov roj hmab rollers yog tsim los ntawm cov txheej txheem casting. Feem ntau, cov tub ntxhais hlau yog muab tso rau hauv nruab nrab ntawm cov pwm cylindrical thiab cov elastomer yog cam khwb cia. Cov cots tshwj xeeb tuaj yeem siv centrifugal casting lossis spin casting. Spin casting tshem tawm qhov xav tau ntawm cov pwm thiab siv chav kub vulcanization los cam khwb cia elastomer systems, txo cov sijhawm ua haujlwm tag nrho.
c. Polyurethane roj hmab log thiab log tsheb
Polyurethane elastomer muaj peev xwm loj, hnav tsis kam, roj tsis kam, thiab ruaj khov rau cov hlau ncej. Nws tuaj yeem siv los tsim cov roj hmab rollers dav siv hauv ntau yam kev sib kis, xws li; ntau lawm kab conveyor siv, qhia rollers, cable tsheb slides, thiab lwm yam .. Nyob rau hauv cov kev taw qhia ntawm kev ua si thiab kev lom zem, lub log ntawm high-end roller skates thiab scooters yog tag nrho cov ua los ntawm polyurethane. Lub log urethane roj hmab kuj muaj cov yam ntxwv ntawm cov roj tsis kam, zoo toughness thiab muaj zog adhesion. Polyurethane kuj tseem siv rau hauv cov khoom siv hluav taws xob me me thiab kev sib kis tau zoo, ntau lub log thoob ntiaj teb, thiab lwm yam. Kuj tseem muaj cov log tsheb micro-foam, PU ua npuas ncauj cov log tsheb, thiab lwm yam.
d. Mechanical accessories
Ntau yam sealing rings, shock-absorbing blocks, couplings, tsheb snow chains, thiab lwm yam.
e. Cov khoom siv khau
Polyurethane elastomer muaj cov yam ntxwv ntawm kev ua haujlwm zoo cushioning, lub teeb yuag, hnav tsis kam, tiv thaiv plam, thiab lwm yam, thiab kev ua haujlwm zoo. Nws tau dhau los ua cov khoom siv hluavtaws tseem ceeb rau cov khau hauv kev lag luam khau, ua rau khau kis las xws li khau baseball, golf pob, thiab ncaws pob. , pob taws, pob taws, ntiv taw lub kaus mom, nrog rau khau boots, kev nyab xeeb khau, khau xws li khau, thiab lwm yam. Cov ntaub ntawv polyurethane siv rau cov ntaub ntawv khau xws li cam khwb cia microcellular elastomers thiab thermoplastic polyurethane elastomers, thiab lwm yam, thiab microcellular elastomer soles yog cov tseem ceeb. . Polyurethane microcellular elastomer yog lub teeb hauv qhov hnyav thiab zoo hauv kev puas tsuaj. Nws yog nyiam los ntawm khau manufacturers. Cov khoom muaj qhov ceev qis thiab muaj ntau dua ntais dua li cov roj hmab ib txwm muaj thiab tshuab cov khoom khau. Microporous polyurethane elastomers feem ntau yog siv rau hauv lub hauv caug thiab insoles ntawm cov khau mus ncig, khau tawv, khau kis las, khau khiab, thiab lwm yam hauv Suav teb. Lawv tsuas yog siv rau hauv cov khau khau tshwj xeeb uas yuav tsum tau hnav tsis kam thiab elasticity txawv teb chaws. Cov qauv tsim tuaj yeem muaj ntau haiv neeg. TPU pob taws rau siab abrasion kuj. Thermally decomposable foaming tus neeg sawv cev tuaj yeem muab ntxiv rau hauv kev txhaj tshuaj molding los ua foamed TPU elastic khau ntaub.
f. Tuag hauv ob sab phlu thiab blanking template rau kev tsim cov ntawv hlau, thiab lwm yam.
Thaum xuas nrig ntaus cov ntawv nyias nrog cov pa hlau tuag, feem ntau muaj burrs ntawm qhov tawg. Lub tshuab stamping ntawm kev hloov cov tsoos hlau pwm nrog polyurethane roj hmab yog ib qho kev dhia hauv cov ntawv hlau stamping tshuab, uas tuaj yeem ua rau lub voj voog tsim pwm, ua kom lub neej ntev ntawm cov pwm, txo cov nqi ntawm cov pwm pwm, thiab txhim kho. qhov zoo thiab qhov ntev ntawm qhov raug, tshwj xeeb tshaj yog tsim rau Nws yog tsim rau kev sim ntau lawm ntawm cov khoom me me thiab nruab nrab thiab cov khoom siv ib zaug, thiab tsim nyog rau nyias thiab nyuaj stamping qhov chaw. Hauv cov nplais thiab cov kab ntau lawm, kev siv PU elastomer hauv ob sab phlu tuaj yeem txo cov nqi tsim khoom, txhim kho kev tsim khoom thiab tawm los. Polyurethane tuaj yeem siv los ua cov pwm pwm. Polyurethane pwm tuaj yeem siv los tsim ntau yam qauv thiab tsim cov khoom zoo nkauj. Nyob rau hauv lub stamping ntau lawm ntawm hlau pwm, polyurethane elastomer rods, raj thiab phaj pads yog siv es tsis txhob ntawm cov hlau springs li buffer Cheebtsam, nrog siab elasticity, yooj, compression siab deformation zog, tsis muaj kev puas tsuaj rau cov pwm.
g. Cov khoom siv kho mob elastomer
Kev kho mob polyurethane elastomers feem ntau yog thermoplastic polyurethanes txawv teb chaws, thiab tseem muaj me me ntawm cam khwb cia polyurethane elastomers thiab microcellular elastomers. Vim nws lub zog siab, hnav tsis kam, biocompatibility, thiab tsis muaj plasticizers thiab lwm yam me me molecule inert additives, polyurethane elastomers tuav txoj haujlwm tseem ceeb hauv cov khoom siv kho mob. Cov khoom siv kho mob polyurethane muaj xws li polyurethane gastroscope hoses, kho mob hoses, dag thiab diaphragm thiab encapsulation cov ntaub ntawv, polyurethane elastic bandages, tracheal tes tsho, thiab lwm yam. [14].
h. Cov kav dej
Siv qhov yooj yim, siab tensile lub zog, cuam tshuam lub zog, tsis kub tsis kam, kub tsis kam, thiab siab compressive zog ntawm polyurethane elastomers, nws yuav ua tau rau ntau yam hoses thiab nyuaj kav, xws li high-pressure hoses, kho mob catheters, roj kav. , cua xa cov kav dej, roj xa cov kav dej, cov xim pleev xim, cov hluav taws kub, cov khoom siv roj xa cov kav dej, thiab lwm yam. Cov kav dej urethane feem ntau extruded los ntawm thermoplastic polyurethane.
