Kev ceev faj rau kev siv Polyurethane Prepolymer
Oct 29, 2021
Polyurethane prepolymer yog ib hom polyurethane prepolymer raws li TDI thiab polyether polyol. Nws muaj cov yam ntxwv ntawm siab elasticity, zoo abrasion tsis kam, qis endogenous tshav kub, thiab hydrolysis kuj. Nws muaj qhov zoo ntawm dynamic kev ua tau zoo. pom tseeb kom zoo dua. Cov khoom ua nrog nws muaj kev ua tau zoo nyob rau hauv cov nqe lus ntawm resilience, tsis tshua muaj kub zog thiab toughness. Tsis tas li ntawd, nws kuj muaj qis dua kev ua haujlwm viscosity thiab lub sijhawm ua haujlwm ntev dua. Nws muaj kev ua haujlwm zoo thaum tsim khoom, tsis hnov tsw rau dej vapor, lub sij hawm luv luv demoulding, siab yield, dav maturation tej yam kev mob, thiab lwm yam. Ntxiv rau kev muab lub cev zoo dua thiab kev ua haujlwm yooj yim, nws kuj muaj kev ua tau zoo hauv kev ua kom muaj kev nyab xeeb ib puag ncig, kev noj qab haus huv thiab kev huv.
Ua tib zoo saib xyuas kev sib khi thaum siv. Yog tias nws tsis tuaj yeem siv tag nrho ib zaug, polyurethane prepolymer tom qab siv yuav tsum tau muab kaw thiab khaws cia hauv kev tiv thaiv nitrogen. Ntawm qhov kub thiab txias, lub prepolymer yuav condense rau hauv cov kua nplaum uas muaj lard. Nws tsis tsim nyog siv hluav taws xob cua sov rods, hluav taws xob ncu thiab lwm yam khoom siv thaum cua sov prepolymer, vim hais tias cov cua sov txoj kev yog heev concentrated thiab yuav ua rau cov khoom hauv zos degradation. Yog li, nws yog feem ntau tsim nyog kom sov lub prepolymer ntawm 70 ° C mus rau 80 ° C. Tsis txhob siv lub prepolymer ua ntej nws tau yaj. Qhov tsis sib xws ntawm prepolymer thiab curing tus neeg sawv cev yuav ua rau ib nrab xim sib txawv ntawm cov khoom.
