Thermoplastic vs Thermoset

Thermoplastic vs Thermoset

Thermoplastic hais txog cov cuab yeej uas cov khoom tuaj yeem ntws thiab deform thaum cua sov, thiab tuaj yeem tswj tau qee yam zoo tom qab txias. Feem ntau cov linear polymers pom cov thermoplasticity thiab yooj yim ua tiav los ntawm extrusion, txhaj tshuaj lossis tshuab molding. Thermosetting yog hais txog cov cuab yeej uas nws tsis tuaj yeem softened thiab molded repeatedly thaum rhuab, thiab nws tsis tuaj yeem yaj hauv cov kuab tshuaj. Cov polymers loj muaj cov cuab yeej no.

Thermosetting yog kev hloov tshuaj. Tom qab ua kom sov, cov qauv tau hloov thiab hloov mus rau lwm yam khoom. Piv txwv li, koj tsis tuaj yeem rov qab lub qe tom qab nws siav. Thermoplasticity yog kev hloov ntawm lub cev. Nws tsuas yog hais tias lub xeev ntawm cov khoom hloov thaum nws yog rhuab, tab sis tus qauv tsis hloov. Nws tseem yog haiv neeg. Piv txwv li, thaum lub tswm ciab melted los ntawm tshav kub, nws yuav rov qab mus rau lub qub tswm ciab, tab sis qhov kub ntawm ib tug tswm ciab yog ib tug tshuaj hloov.

1. Cov thermoplastics

Nws yuav mos thiab kua thaum rhuab, thiab hardens thaum txias. Cov txheej txheem no yog thim rov qab thiab tuaj yeem ua repeated. Polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyoxymethylene, polycarbonate, polyamide, acrylic yas, lwm yam polyolefins thiab lawv cov copolymers, polysulfide, polyphenylene ether, chlorinated polyether, thiab lwm yam Nws yog thermoplastic. Cov resin molecular chains nyob rau hauv thermoplastics yog tag nrho cov linear los yog branched. Tsis muaj tshuaj lom neeg ntawm cov saw hlau molecular, thiab lawv soften thiab ntws thaum rhuab. Cov txheej txheem ntawm kev ua kom txias thiab hardening yog ib qho kev hloov ntawm lub cev.

2. Cov yas thermosetting

Thaum nws yog cua sov thawj zaug, nws tuaj yeem muag thiab ntws. Thaum nws yog rhuab mus rau ib tug tej yam kub, ib tug tshuaj tiv thaiv tshwm sim rau cross-links thiab solidify rau harden. Qhov kev hloov no yog irreversible. Tom qab ntawd, thaum nws sov dua, nws tsis tuaj yeem ua mos thiab ntws. Nws yog los ntawm kev tsim txiaj ntawm cov yam ntxwv no uas cov txheej txheem molding yog nqa tawm, thiab cov yas ntws thaum lub sij hawm thawj cua sov yog siv los sau cov kab noj hniav nyob rau hauv siab, thiab tom qab ntawd solidify rau hauv cov khoom ntawm ib tug txiav txim zoo thiab loj. Cov khoom no hu ua thermoset.

Cov resin ntawm thermosetting plastics yog linear lossis branched ua ntej kho. Tom qab kho, tshuaj bonds yog tsim ntawm molecular chains los ua ib tug peb-seem network qauv. Tsis tsuas yog nws tsis tuaj yeem yaj dua, tab sis nws tsis tuaj yeem yaj hauv cov kuab tshuaj. Phenolic, aldehyde, melamine formaldehyde, epoxy, unsaturated polyester, silicone thiab lwm yam yas yog tag nrho cov thermosetting yas.

Thermoplastic vs Thermoset