PBT thiab ethylene terephthalate yog ob qho tib si semi-crystalline thermoplastic polyesters, qhov txawv vim qhov txawv ntawm glycol siv rau hauv lub polymerization. Piv nrog cov tsiaj ntawv, cov khoom nyhav dua siab dua cov khoom noj khoom haus, cov khoom me me, cov teeb meem me me, thiab cov khoom siv dag zog yog me ntsis qis dua li cov tsiaj ntawv, nws zoo li tias PBT tsis tuaj yeem sib tw nrog tus tsiaj.
Txawm li cas los xij, vim yog siv cov kab uas muaj plaub-carbon tshaj tawm, qhov yooj yim ntawm cov duab polymer yog kho kom zoo, uas yog pom los ntawm tus txheej txheem ceev crystallization, uas ua rau lub sij hawm voj voog ntawm kev txhaj tshuaj molding thaum lub sijhawm ua tiav ntawm PBT yam khoom xyaw engineering, thiab tawm ntawm mold dawb paug txhim kho. Qhov zoo crystallization cov cuab yeej thaum lub sij hawm cov txheej txheem molding ua rau stability stability ntawm cov khoom thiab cov nyiaj pabcuam li siab dua.
Tsis tas li ntawd, kev siv plaub daim ntawv cawv kuj ua rau PBT fibers tau zoo dua elasticity thiab yooj, thiab zoo siv fibers thiab txhuam hniav. PBT yog khoom ntawm yaj polycondensation ntawm dimethyl terephthalate los yog terephthalic acid thiab butanediol. Los ntawm kev tswj lub sij hawm polymerization thiab cov degree ntawm lub tshuab nqus tsev, ib yam khoom nrog ib tus txheeb ze molecular ntawm 17,000-40000 tuaj yeem tau. Cov kab mob txheeb ze molecular tuaj yeem tau los ntawm cov theem ua ntej theem polycondensation. PBT muaj kub hloov qhov kub (24 ° C) ze rau qhov chaw sov, tsawg tshaj li tus tsiaj (76 ° C), ze rau polyamide (40 ° C); melting point yog qis tshaj li tus tsiaj nyob ze rau polyamide; crystallization tus nqi yog 15 npaug ntawm cov tsiaj ntawv, thiab zoo li cov hlwv zoo li 66. Qhov txawv ntawm qhov sib txawv ntawm lub cev PBT thiab PET ua rau lawv sib txawv hauv kev ua tus cwj pwm thiab daim ntawv thov. Qhov tsawg crystallization thiab kev coj cwj pwm siab ntawm tus tsiaj hauv kev xa tom qab yog tsim rau cov roj thiab cov yeeb yaj kiab, thaum PBT ceev-crystallizing yog tsim. Engineering yas.
