Khoom npe:polyurethane

Khoom Qauv Qauv Qauv:

Tshuaj lom neeg cov khoom:

Polyurethanes tau ua thawj zaug ua ntej thiab tshawb fawb los ntawm Dr. otto Bayer xyoo 1937. Polyurethane yog cov polymer uas yog chav rov qab muaj qhov urethane. Urethanes yog derivatives ntawm carbamic acids uas muaj nyob rau hauv daim ntawv ntawm lawv esters [15]. Qhov loj tau txais txiaj ntsig ntawm PU yog tias txoj saw hlau tsis tsim nyog tshwj xeeb ntawm cov pa roj carbon atoms tab sis es ntawm heteroatoms, oxygen, pa roj carbon thiab nitrogen [4]. Rau cov ntawv thov muaj kev lag luam, polyhydroxyl compound yuav siv tau. Ib yam li ntawd, Poly-Functional Nitrogen cov tebchaw tuaj yeem siv rau ntawm cov chaw nyob ua ke. Los ntawm kev hloov pauv thiab sib txawv ntawm polyhyduntexyl thiab polyfunctional nitrogen sib xyaw, cov kua txiv sib txawv tuaj yeem ua ke [15]. Polyester lossis polyether ciaj sia muaj cov pab pawg hydroxyl tau siv los tsim Polyesteror Polyether-Pu, ntsig txog [6]. Kev sib txawv hauv cov xov tooj ntawm cov chaw hloov chaw thiab nyob rau hauv ceg sib dhos tsim pus lining los ntawm legar mus rau branched thiab 9exible rau rigid. Tawm pus yog siv rau kev tsim cov fibers thiab moulding [6]. Saj zawg zog pus yog siv nyob rau hauv kev tsim cov kev cog qoob loo thiab cov tsho tiv no [5]. Saj zawg zog thiab cov figid foamed plastics, uas ua rau feem ntau cov kua paug tsim tawm, tuaj yeem nrhiav tau hauv ntau hom kev lag luam [7]. Siv cov molecular tsawg molecular txheej, ntau cov block copolymers tuaj yeem tsim tawm. Lub davhlau ya nyob davhlau ya nyob twg hydroxyl tso cai rau lwm cov blocks, hu ua ntu, yuav tsum tau ntxig rau hauv cov saw pu. Kev sib txawv ntawm cov ntu cov txiaj ntsig tau ua rau cov qib sib txawv ntawm lub zog tensile thiab elasticity. Cov blocks muab cov theem nruj rigid crystalline thiab muaj cov saw txuas txuas mus rau cov ntu nyuaj [7]. Cov yielding ib tug amorphous rubbery theem thiab muaj cov polyester / Polyether yog hu ua ntu mos. Kev Lag Luam, cov block polymers yog hu ua segmented pus

Daim Ntawv Thov:

Saj zawg zog polyurethane feem ntau yog cov qauv kab nrog thermoplastic, cov khoom siv tshuaj tiv thaiv zoo dua li PVC ua npuas ncauj, nrog tsawg dua kev hloov pauv hloov pauv. Nws muaj cov pa thermal zoo, suab rwb thaiv tsev, poob siab tsis kam thiab tiv thaiv cov tshuaj tiv thaiv lom. Yog li ntawd, nws yog siv los ua ntim, lub suab rwb thaiv tsev thiab cov ntaub ntawv lim. Rigid Polyurethane yas yog lub teeb, cov tshuaj tiv thaiv zoo tshaj, cov hluav taws xob zoo, kev ua haujlwm zoo, thiab dej tsis haum. Nws yog tsuas yog siv raws li cov khoom siv qauv rau kev tsim kho, tsheb, kev lag luam aviation thiab rwb thaiv tsev sov. Polyurethane elastomer kev ua tau zoo ntawm cov yas thiab roj hmab, cov roj ua tsis kam, cov kev tiv thaiv tsis tshua muaj, siab tawv, elasticity. Nws yog tsuas yog siv nyob rau hauv cov khau kev lag luam thiab kev lag luam kev lag luam. Polyurethane tseem tuaj yeem ua rau hauv cov nplaum, cov tawv nqaij, cov khoom siv hluavtaws, thiab lwm yam.