TPU Molecular Structure

Chain ntu qauv
TPU yog ib qho (AB) n-hom block linear polymer tsim los ntawm cov khoom siv tau yooj yim thiab cov ntu tawv tawv. TPUs nrog cov qauv sib txawv muaj qhov sib txawv, thiab cov qauv ntu feem ntau txiav txim siab los ntawm hom khoom siv raw. Qhia cov pab pawg rau hauv cov qauv molecular tuaj yeem txo cov kev taw qhia crystallinity ntawm macromolecules, ua rau txo qis hauv cov khoom siv kho tshuab thiab txo qhov kev ua haujlwm o; Ib qho ntawm cov tshuaj crosslinking tuaj yeem txhim kho qhov kev ntxhov siab elongation thiab hnyav tsis kam ntawm elastomer, thiab txo qis deformation mus tas li.
Cov ntsiab lus nyuaj ntu
Cov ntsiab lus nyuaj yog hais txog qhov feem pua ​​​​ntawm cov ntu nyuaj hauv nruab nrab, thiab yog qhov tseem ceeb hauv kev tsim qauv. Hydrogen bonding, microphase sib cais degree, thiab crystallization kev ua tau zoo ncaj qha cuam tshuam los ntawm cov ntsiab lus ntawm cov ntu nyuaj yog qhov tseem ceeb hauv kev txiav txim siab lawv cov morphology. Feem ntau hais lus, nrog qhov nce ntawm cov ntsiab lus nyuaj, qhov hardness, modulus, thiab tsim kua muag lub zog ntawm TPU nce, thaum lub elongation ntawm tawg txo.
Isocyanate Index
Vim lub synthesis mechanism ntawm TPU ua ib tug gradual ntxiv polymerization cov tshuaj tiv thaiv ntawm kev ua hauj lwm pab pawg neeg, lub isocyanate Performance index r {{0}}} (molar ratio ntawm diisocyanate rau oligomer glycol) ncaj qha cuam tshuam rau lub molecular hnyav. Thaum r0 Tsawg dua lossis sib npaug rau 1, qhov hnyav molecular ntawm TPU nce nrog qhov nce ntawm r0. Thaum r0=1, qhov hnyav molecular nce mus txog qhov siab tshaj plaws, thiab tom qab ntawd txuas ntxiv nce tus nqi r0, thiab qhov hnyav molecular pib dua. Thaum r0 nyob nruab nrab ntawm 0.95-1, TPU modulus, tensile zog, kua muag zog, thiab lwm yam. nce nrog nce r0.