PLA, cov khoom siv biodegradable, yog semi-crystalline polymer nrog melting kub txog 180 ℃.Yog li vim li cas cov khoom tsis zoo thaum tshav kub kub ua haujlwm thaum nws tau ua?
Qhov laj thawj tseem ceeb yog vim li cas cov crystallization ntawm PLA qeeb thiab crystallinity ntawm cov khoom yog tsawg hauv cov txheej txheem ntawm kev ua haujlwm zoo tib yam thiab molding.Nyob rau hauv cov nqe lus ntawm cov qauv tshuaj, cov saw molecular ntawm PLA muaj ib tug -CH3 ntawm lub chiral carbon atom, uas muaj ib tug raug helical qauv thiab tsis tshua muaj kev ua si ntawm saw segments.Lub peev xwm crystallization ntawm cov ntaub ntawv polymer yog ze ze rau kev ua ntawm molecular saw thiab nucleation muaj peev xwm.Nyob rau hauv cov txheej txheem txias ntawm cov txheej txheem molding zoo tib yam, qhov kub qhov qhov rais haum rau crystallization yog me me, yog li cov crystallinity ntawm cov khoom kawg yog me me thiab thermal deformation kub yog tsawg.
Kev hloov pauv nucleation yog ib txoj hauv kev zoo los ua kom cov crystallinity ntawm PLA, ceev cov crystallization tus nqi, txhim kho cov cuab yeej crystallization thiab yog li ua kom cov cua sov ua haujlwm ntawm PLA.Yog li, kev hloov kho ntawm PLA cov ntaub ntawv xws li nucleation, kev kho cua sov thiab crosslinking muaj lub luag haujlwm tseem ceeb hauv kev nthuav dav daim ntawv thov ntau yam ntawm PLA cov khoom los ntawm kev nce nws cov thermal deformation kub thiab txhim kho nws cov cua sov.
Nucleating agents tau muab faib ua inorganic nucleating agents thiab organic nucleating agents.Inorganic nucleating agents feem ntau suav nrog phyllosilicates, hydroxyapatite thiab nws cov derivatives, carbon cov ntaub ntawv thiab lwm yam inorganic nanoparticles.Av nplaum yog lwm hom txheej txheej silicate ntxhia cov ntaub ntawv uas feem ntau siv hauv PLA hloov kho, ntawm cov montmorillonite yog tus sawv cev tshaj plaws.Lub ntsiab organic nucleating agents yog: amide compounds, bisylhydrazides thiab biureas, biomass me molecules, organometallic phosphorus / phosphonate thiab polyhedral oligosiloxy.
Qhov sib ntxiv ntawm cov nucleating complex additives los txhim kho nws cov thermal stability yog zoo dua li ntawm ib qho additives.Lub ntsiab degradation daim ntawv ntawm PLA yog hydrolysis tom qab hygroscopic, yog li cov txheej txheem ntawm yaj blending kuj siv tau, ntxiv hydrophobic additive dimethylsilicone roj los txo cov khoom hygroscopic, ntxiv alkaline additives los txo tus nqi degradation ntawm PLA los ntawm kev hloov PH nqi ntawm PLA.
Post lub sij hawm: Nov-07-2022