Cov nyhuv ntawm Mos Segment ntawm Polyurethane Elastomer ntawm nws cov cuab yeej cuab tam
Urethane elastomer (PUE) feem ntau yog tsim los ntawm oligomer polyols, polyisocyanates thiab saw extenders ua raw khoom. Nws cov khoom siv kho tshuab tuaj yeem hloov kho ntau yam. Nws tuaj yeem ua ke los ntawm kev xaiv cov ntaub ntawv tsim nyog raws li kev xav tau los npaj cov khoom ua tau raws li qhov xav tau. Feem ntau hais lus, oligomer polyol tsim cov ntu mos ntawm polyurethane, polyisocyanate thiab cov saw txuas ntxiv ua rau ntu nyuaj, thiab kev sib cais microphase tshwm sim ntawm ntu mos thiab ntu nyuaj, kom PUE muaj kev ua tau zoo heev. Muaj ntau txoj kev faib tawm rau PUE: raws li nws cov txheej txheem ua tiav, nws tuaj yeem muab faib ua peb hom: hom casting, hom thermoplastic thiab hom sib xyaw; Raws li cov txheej txheem tshuaj tiv thaiv, nws tuaj yeem muab faib ua ib-kauj ruam txoj kev thiab ob-kauj ruam txoj kev; Hom cawv tuaj yeem muab faib ua hom polyether thiab hom polyester.
1 Kev sim ib feem
1.1 Cov khoom siv raw thiab cov cuab yeej siv
Tetrahydrofuran homopolyether polyol (PTMG): Mn=1000 thiab Mn=2000, Nyiv Mitsubishi Chemical Corporation, cov khoom lag luam; Polycaprolactone polyol (PCL): Mn=2000, Nyiv Daicel Chemical Industry Co., Ltd., cov khoom lag luam; polybutylene adipate diol (PBA, Mn=1000, 2000), polyethylene adipate diol (PEA, Mn=2000): Yantai Huada Chemical Co., Ltd., cov khoom lag luam; Polycarbonate diol (PCDL): Mn=2000, Asahi Kasei Chemical Co., Ltd., cov khoom lag luam; 4, 4' - Diphenylmethane diisocyanate (MDI): Yantai Wanhua Polyurethane Co., Ltd., cov khoom lag luam; 1, 4 – Butanediol (BDO): Beijing Chemical Plant, analytical qib; Dibutyltin dilaurate (T12): Tianjin Ruijinte Chemicals Co., Ltd., qib reagent.
Electronic universal xeem tshuab: Qauv CMT6104, Shenzhen Xinsansi Measurement Technology Co., Ltd.; Roj Hmab Durometer: Qauv LX-A, Yingkou Experimental Materials Factory.
1.2 Synthesis of PUE
1.2.1 Prepolymer npaj
Lub cev qhuav dej ntawm oligomer polyol nyob rau hauv lub tshuab nqus tsev ntawm 100 ~ 110 degree rau 2h, txias rau 50 ~ 55 degree rau kev siv; ncuav lub melted MDI rau hauv ib lub raj mis peb-caj dab, thaum lub MDI kub poob mus rau 50 ~ 55 degree, ntxiv cov metered Rau zoo oligomer polyols, thawj react ib txwm rau 30 feeb yam tsis muaj cua sov, thiab ces do thiab cua sov rau 2 teev ntawm 80 ~ 85 degree, coj cov qauv los soj ntsuam cov feem ntau ntawm NCO, thiab xaus cov tshuaj tiv thaiv thaum tus nqi tsom xam ze rau tus nqi tsim. Lub prepolymer tuaj yeem muab tau, uas yog kaw thiab khaws cia rau tom qab siv.
1.2.2 Kev npaj Elastomer
Ntsuas tus nqi tsim nyog ntawm prepolymer, ntxiv BDO thiab T12 hauv kev faib ua feem, do sai thiab sib npaug, ncuav rau hauv preheated 120 degree ca pwm, thiab nias thiab kho rau 30 feeb thaum nws ncav cuag lub gel. Cov khoom siv kho tshuab tau sim tom qab kho rau 18h hauv qhov cub ntawm chav sov rau 24h.
1.3 Test method
NCO cov ntsiab lus raug txiav txim raws li HG/T2409-1992; Shore A hardness yog txiav txim raws li GB/T531.1-2008; 300 feem pua tensile stress, elongation ntawm so thiab tensile zog yog txiav txim raws li GB/T528-2009; lub zog tsim kua muag yog txiav txim raws li GB/T531.1-2008 GB/T529-2008 kev txiav txim.
2.1 Cov nyhuv ntawm oligomer polyols ntawm cov khoom siv kho tshuab ntawm PUE
Ntau hom thiab cov qauv molecular ntawm oligomer polyols muaj kev cuam tshuam ncaj qha rau cov khoom siv kho tshuab ntawm PUE. Siv cov polyether polyol thiab polyester polyol nrog tib tus txheeb ze molecular mass (ob leeg 2000), khaws cov feem ntawm cov mos mos ntawm 55 feem pua, synthesize prepolymer nrog MDI, saw extension coefficient [n(OH) nyob rau hauv lub system: n(NCO )] yog 1, lub prepolymer yog chain-extended nrog BDO, thiab txhua yam khoom ntawm PUE npaj tau qhia nyob rau hauv Table 1.
Nws tuaj yeem pom los ntawm Table 1 tias thaum w(NCO) ntawm cov prepolymer zoo ib yam, cov khoom siv kho tshuab ntawm PUE uas nws cov ntu muag yog PCL, PBA, PEA thiab PCDL feem ntau zoo dua li cov uas nws qhov muag yog PTMG. Qhov no yog vim PCL, PBAPEA thiab PCDL yog tag nrho cov polyester polyols nrog ester pawg sab hauv, thaum PTMG yog ib tug polyether polyol nrog ether pawg nyob rau hauv, thiab ester pawg muaj ntau polar tshaj ether pawg, ua rau sab hauv ntawm polyurethane yooj yim dua Hydrogen bonds yog generated, thiab cov khoom siv kho tshuab zoo dua. Nyob rau hauv polyester PUE, vim hais tias PCDL muaj carbonate pawg, polarity yog qhov loj tshaj plaws, thiab cov PUE tau txais muaj qhov siab tshaj plaws ntawm crystallinity nyob rau hauv cov mos mos, yog li nws hardness thiab tensile lub zog yog siab tshaj, thiab elongation ntawm tawg yog qhov qis tshaj; cov ntsiab lus ntawm ester pawg hauv PCL Qhov qis tshaj Shore A hardness thiab tensile lub zog, thiab qhov siab tshaj plaws elongation ntawm tawg; PBA thiab PEA muaj ntau pawg PEA ester, tab sis vim tias cov saw txuas txuas siv BDO, cov pa roj carbon atoms ntawm ob pawg hydroxyl yog 4, thiab PEA muaj 2 carbon atoms tsawg dua PBA. Cov qauv ntawm PBA thiab BDO zoo sib xws, qhov tshwm sim ntawm polyurethane yog ntau zaus, thiab crystallinity muaj zog dua. Yog li ntawd, kev ua tau zoo ntawm PUE synthesized los ntawm PBA raws li ib tug mos ntu zoo dua li ntawm PEA.
2.2 Cov nyhuv ntawm qhov hnyav molecular ntawm oligomer polyol ntawm cov khoom siv kho tshuab ntawm PUE
Tib yam ntawm oligomer polyols nrog sib txawv cov txheeb ze molecular luj yog siv los ua ke polyurethane, vim hais tias qhov luaj li cas ntawm cov mos segment yog txawv, thiab lub zog ntawm lub mechanical zog ntawm PUE kuj txawv. Siv polyether polyol thiab polyester polyol nrog sib txawv cov txheeb ze molecular luj, khaws tib yam w(NCO), synthesize prepolymer nrog MDI, siv BDO raws li chain extender, thiab cov saw extension coefficient yog 1. Cov neeg kho tshuab zog ntawm lub npaj elastomer yog qhia nyob rau hauv lub rooj. 2.
Raws li tau pom los ntawm Table 2, seb nws puas yog polyester PUE synthesized los ntawm PBA los yog polyether PUE synthesized los ntawm PTMG, thaum lub w(NCO) ntawm lub prepolymer yog tib yam, nrog rau qhov nce ntawm cov txheeb ze molecular hnyav ntawm oligomer polyol, PUE yuav raug txo kom tsawg. Lub hardness, 300 feem pua tensile kev nyuaj siab, tensile zog thiab lub zog tsim kua muag poob, thaum lub elongation ntawm tawg nce. Thaum cov txheeb ze molecular loj ntawm oligomer polyol nce, lub polarity ntawm lub npaj PUE poob, uas yog tsis conducive rau tsim hydrogen bonds, lub degree ntawm microphase sib cais ntawm cov mos thiab tawv ntu yog tsis muaj zog, thiab muaj feem xyuam rau hardness, modulus. thiab lub zog raug txo; Cov txheeb ze molecular loj ntawm oligomer polyols nce, uas ua rau tsis muaj zog ntawm kev sib cuam tshuam ntawm hydrogen bonds, txo cov crystallization nyiam ntawm cov mos mos, tswj lub siab elasticity ntawm PUE, thiab tsub kom lub elongation ntawm so.
2.3 Cov txiaj ntsig ntawm NCO cov ntsiab lus ntawm cov khoom siv kho tshuab ntawm polyurethane elastomers
Cov ntsiab lus NCO sib txawv ntawm prepolymer yuav ua rau cov ntsiab lus sib txawv ntawm cov ntu mos ntawm hluavtaws PUE, yog li cuam tshuam rau cov khoom siv hluav taws xob ntawm elastomer. Ua ntej, polyether polyol thiab polyester polyol ntawm tib tus txheeb ze molecular loj tau siv los ua ke prepolymers nrog sib txawv NCO qhov tseem ceeb nrog MDI. Lub cev thiab cov khoom siv kho tshuab tau qhia hauv Table 3.
Nws tuaj yeem pom los ntawm Table 3 tias seb nws puas yog polyester PUE synthesized los ntawm PBA lossis polyether PUE synthesized los ntawm PTMG, nrog rau qhov nce ntawm prepolymer w (NCO), hardness, 300 feem pua tensile stress, tensile zog thiab tearing zog ntawm PUE nce. Lub zog tawg tau nce, thaum lub elongation ntawm kev tawg qis. Qhov no yog vim tias qhov siab dua w (NCO) hauv cov khoom siv prepolymer, cov ntsiab lus ntawm polyisocyanate ntau dua, thiab tib lub sijhawm, cov nyiaj ntawm cov saw txuas ntxiv yuav nce ntxiv, uas yuav ua rau cov ntsiab lus nyuaj ntawm PUE thiab nce hardness; w(NCO) nyob rau hauv lub prepolymer yuav nce. ), cov pab pawg urethane nce, lub polarity ntawm polyurethane ua loj, thiab cov degree ntawm microphase sib cais nce los ua kom cov modulus thiab lub zog; qhov nce ntawm w (NCO) ua rau nws yooj yim dua los tsim hydrogen bonds hauv polyurethane, thiab hydrogen bond sib cuam tshuam nce. loj, yog li lub elongation txo.
2.4 Kev cuam tshuam ntawm cov saw txuas ntxiv coefficient ntawm cov khoom siv kho tshuab ntawm PUE
Yog hais tias cov saw txuas ntxiv coefficient sib txawv, tus nqi ntawm cov saw txuas ntxiv siv yuav txawv, uas yuav ua rau cov ntsiab lus sib txawv ntawm cov khoom siv hluavtaws PUE, yog li cuam tshuam rau cov khoom siv ntawm PUE. Siv polyether polyol thiab polyester polyol ntawm tib tus txheeb ze molecular mass, ua tib yam w (NCO), synthesizing ib prepolymer nrog MDI, ces hloov cov saw extension coefficient, thiab siv BDO mus cuag cov saw ntawm prepolymer, npaj PUE mechanics. kev ua tau zoo yog qhia hauv Table 4.
Nws tuaj yeem pom los ntawm Table 4 tias seb nws puas yog polyester PUE synthesized los ntawm PBA lossis polyether PUE synthesized los ntawm PTMG, thaum w(NCO) ntawm prepolymer yog tib yam, nrog rau kev nce ntawm cov saw txuas ntxiv coefficient, hardness ntawm PUE, 300 feem pua Cov tensile stress, elongation ntawm break, tensile zog thiab tsim kua muag lub zog ua ntej thiab tom qab ntawd txo, thiab cov khoom siv kho mob yog qhov zoo tshaj plaws thaum cov saw txuas ntxiv coefficient yog 1.00. Qhov no yog vim hais tias thaum cov saw txuas ntxiv coefficient yog 1. Thaum cov saw txuas txuas ntxiv qis dua 1. Thaum cov saw txuas ntxiv coefficient ntau dua 1.00, vim tias cov saw txuas ntxiv ntau dhau, nws tuaj yeem ua tau raws li cov saw txuas ntxiv. Muaj cov residues, thiab cov residues ua raws li plasticizers kom degrade cov khoom ntawm PUE.
Xaus
① Thaum lub prepolymer w (NCO) zoo ib yam: cov khoom siv kho tshuab ntawm PUE uas nws cov ntu muag yog PCL, PBA, PEA, thiab PCDL feem ntau zoo dua li cov uas nws cov ntu muag yog PTMG; Hardness, 300 feem pua tensile kev nyuaj siab, tensile zog thiab lub zog tsim kua muag poob, thaum elongation ntawm tawg nce; Nrog rau qhov nce ntawm cov saw txuas ntxiv coefficient, qhov hardness, 300 feem pua tensile stress, elongation ntawm so, tensile lub zog ntawm PUE Lub zog thiab tsim kua muag lub zog qhia ib tug qauv ntawm nce ua ntej thiab ces txo, thiab thaum lub saw extension coefficient yog 1.00, cov neeg kho tshuab cov khoom yog qhov zoo tshaj plaws.
② Nrog rau qhov nce ntawm prepolymer w (NCO), hardness, 300 feem pua tensile kev nyuaj siab, tensile lub zog thiab kua muag zog ntawm PUE nce, thaum lub elongation ntawm tawg poob.
