Qhov sib txawv tseem ceeb ntawm cov thermoplastic thiab cov thermoset yog cov thermoplastic tuaj yeem yaj rau hauv ib qho duab thiab rov siv dua thaum cov thermosets muaj cov duab ruaj khov thiab tsis tuaj yeem rov ua dua tshiab rau hauv cov ntawv yas.
Thermoplastic thiab thermoset yog cov ntsiab lus uas peb siv los ua tus yam ntxwv ntawm cov polymers nyob ntawm lawv tus cwj pwm thaum raug cua sov, yog li cov lus hais ua ntej, 'thermo'. Polymers yog cov molecules loj uas muaj cov subunits rov qab.
Thermoplastic yog dab tsi?
Peb hu cov thermoplastics 'Thermo-softening Plastics' vim tias peb tuaj yeem yaj cov khoom no thaum kub kub thiab tuaj yeem txias kom rov qab tau cov ntaub ntawv. Thermoplastics feem ntau yog qhov hnyav molecular. Cov saw hlau polymer yog txuas ua ke los ntawm kev sib cuam tshuam cov rog. Peb tuaj yeem rhuav tshem cov kev sib cuam tshuam no yooj yim yog tias peb muab lub zog txaus. Qhov no piav qhia vim li cas cov polymer no tuaj yeem ua tau thiab yuav yaj thaum cua sov. Thaum peb muab lub zog txaus kom tshem tawm ntawm cov rog sib xyaw uas tuav cov polymer ua cov khoom, peb tuaj yeem pom cov khoom yaj. Thaum peb txias nws rov qab, nws tso tawm cov cua sov thiab rov tsim cov intermolecular rog, ua rau nws muaj zog. Yog li ntawd, cov txheej txheem yog thim rov qab.
Daim duab 01: Thermoplastics
Thaum cov polymer melted, peb tuaj yeem ua nws rau hauv cov duab sib txawv; Thaum rov ua kom txias, peb tuaj yeem tau txais cov khoom sib txawv thiab. Thermoplastics kuj qhia cov khoom sib txawv ntawm lub cev ntawm lub melting point thiab qhov kub ntawm cov khoom siv lead ua. Tsis tas li ntawd, peb tuaj yeem pom tias lawv muaj qhov zoo sib xws ntawm qhov kub thiab txias. Qee cov thermoplastics muaj xws li Nylon, Teflon, Polyethylene thiab Polystyrene.
Thermoset yog dab tsi?
Peb hu cov thermosets 'Thermosetting Plastics'. Lawv muaj peev xwm tiv taus qhov kub thiab txias yam tsis muaj melting. Peb tuaj yeem tau txais cov cuab yeej no los ntawm kev sib zog los yog ua kom tawv nqaij mos thiab khov ua ntej-polymer los ntawm kev qhia txog kev sib txuas ntawm cov saw hlau polymer. Cov kev sib txuas no tau nthuav tawm ntawm cov chaw siv tshuaj lom neeg (unsaturation thiab lwm yam) nrog kev pab ntawm cov tshuaj tiv thaiv tshuaj. Feem ntau, peb paub cov txheej txheem no yog 'kho' thiab peb tuaj yeem pib nws los ntawm kev ua kom sov cov khoom siab tshaj 200˚C, UV hluav taws xob, hluav taws xob hluav taws xob siab thiab siv cov khoom siv ntxiv. Cov kab sib txuas yog cov khoom siv tshuaj ruaj khov. Thaum lub polymer yog cross-liked, nws tau txais ib tug nruj heev thiab muaj zog 3D qauv, uas tsis kam yaj thaum cua sov. Yog li ntawd, cov txheej txheem no yog irreversible converting cov khoom pib mos mus rau hauv ib tug thermally ruaj khov polymer network.
Daim duab 02: Kev sib piv ntawm Thermoplastic thiab Thermoset Elastomers
Thaum tus txheej txheem ntawm kev sib txuas, qhov hnyav molecular ntawm polymer nce; li no lub melting point nce. Thaum lub melting point mus saum lub ambient kub, cov ntaub ntawv tseem nyob ruaj khov. Thaum peb ua kom sov cov thermosets kom tsis txhob muaj qhov kub thiab txias, lawv decompose es tsis txhob melting vim mus txog qhov decomposition point ua ntej melting point. Qee qhov piv txwv ntawm cov thermosets suav nrog Polyester Fiberglass, Polyurethanes, Vulcanized Rubber, Bakelite, thiab Melamine.
Qhov txawv ntawm Thermoplastic thiab Thermoset yog dab tsi?
Thermoplastic thiab thermosets yog ob hom khoom siv polymer. Qhov sib txawv tseem ceeb ntawm thermoplastic thiab thermoset yog tias nws tuaj yeem yaj cov thermoplastic rau hauv ib qho duab thiab rov siv dua thaum cov thermosets muaj cov duab tas mus li thiab tsis tuaj yeem rov ua dua tshiab rau hauv cov ntaub ntawv yas. Ntxiv mus, cov thermoplastics yog moldable thaum thermoset yog nkig. Thaum muab piv rau lub zog, cov thermosets muaj zog dua li cov thermoplastics, qee zaum txog 10 npaug zog.
Summary – Thermoplastic vs Thermoset
Thermoplastic thiab thermoset yog polymers. Qhov sib txawv tseem ceeb ntawm cov thermoplastic thiab thermoset yog tias nws tuaj yeem yaj cov thermoplastic rau hauv ib qho duab thiab rov siv dua thaum cov thermosets muaj cov duab ruaj khov thiab tsis tuaj yeem rov ua dua tshiab rau hauv cov ntaub ntawv yas.
