Polyester ndi gulu lama polimazomwe zili ndiester gulu logwira ntchitomu gawo lililonse lobwereza la unyolo wawo waukulu.Monga mwachindunjizakuthupi, nthawi zambiri amatanthauza mtundu wotchedwapolyethylene terephthalate(PET).Ma polyesters amaphatikizapo mankhwala omwe amapezeka mwachilengedwe, monga muzomeranditizilombo, komanso zopangira mongapolybutyrate.Ma polyesters achilengedwe ndi ochepa opangidwa ndizosawonongeka, koma ma polyester ambiri opangira si.Ma polyesters opangidwa amagwiritsidwa ntchito kwambiri pazovala.
Ulusi wa poliyesitala nthawi zina amapota pamodzi ndi ulusi wachilengedwe kuti apange ansalundi katundu wosakanikirana.Thonje-zophatikizika za polyester zimatha kukhala zolimba, makwinya- komanso osagwetsa misozi, komanso kuchepetsa kuchepa.Synthetic ulusipogwiritsa ntchito poliyesitala ali ndi madzi apamwamba, mphepo ndi kukana chilengedwe poyerekeza ndi ulusi wopangidwa ndi zomera.Iwo ndi ochepazosagwira motondipo imatha kusungunuka ikayaka.
Ma polyesters amadzimadzi amadzimadzi ndi amodzi mwazinthu zoyamba kugwiritsidwa ntchito m'mafakitalema polima amadzimadzi a kristalo.Amagwiritsidwa ntchito pazinthu zawo zamakina komanso kukana kutentha.Makhalidwewa ndi ofunikiranso pakugwiritsa ntchito kwawo ngati chisindikizo chotha kutha mu injini za jet.
Ma polyesters omwe amapezeka m'chilengedwe amaphatikizapocutinchigawo chambewu cuticles, yomwe imakhala ndiomega hydroxy acidsndi zotumphukira zawo, zolumikizidwa kudzeraesterzomangira, kupanga poliyesitala ma polima a indeterminate kukula.Ma polyesters amapangidwanso ndinjuchimu genusMagulu, zomwe zimapanga acellophane-monga poliyesitala pama cell awo apansi panthaka omwe amawapatsa dzina loti "polyester njuchi".
Kutengera kapangidwe ka mankhwala, polyester ikhoza kukhala athermoplastickapenathermoset.Palinsopolyester utomonikuchiritsidwa ndi owumitsa;komabe, ma polyesters omwe amapezeka kwambiri ndi thermoplastics.[11]Gulu la OH likuchitidwa ndiIsocyanatentchito pawiri mu 2 chigawo dongosolo kupanga zokutira zimene mwina kusankha pigmented.Ma polyesters monga thermoplastics amatha kusintha mawonekedwe atatha kugwiritsa ntchito kutentha.Ngakhale zimayaka pakatentha kwambiri, ma polyesters amakonda kung'ambika ndi moto ndikuzimitsa okha akayaka.Ulusi wa polyester ndi wapamwambakupirirandiE-modulekomanso kuyamwa kwamadzi otsika komanso kochepakuchepapoyerekeza ndi ulusi wina wamakampani.
Kuchulukitsa magawo onunkhira a polyester kumawonjezera awogalasi kusintha kutentha, kutentha kosungunuka,kukhazikika kwamafuta, kukhazikika kwa mankhwala, ndi kukana zosungunulira.
Ma polyesters angakhalensotelechelic oligomersmonga polycaprolactone diol (PCL) ndi polyethylene adipate diol (PEA).Kenako amagwiritsidwa ntchito ngatima polima.
Nthawi yotumiza: Dec-06-2022