I-PLA, i-biodegradable material, iyi-polymer e-semi-crystalline enezinga lokushisa elincibilikayo elifinyelela ku-180 ℃.Kungani-ke okokusebenza kubi kangaka ekumelaneni nokushisa uma sekwenziwe?
Isizathu esiyinhloko ukuthi izinga le-crystallization ye-PLA lihamba kancane futhi i-crystallinity yomkhiqizo iphansi ekucubunguleni okujwayelekile nokubunjwa.Ngokuya ngesakhiwo samakhemikhali, iketango lamangqamuzana e-PLA liqukethe i- -CH3 ku-athomu ye-chiral carbon, enesakhiwo esivamile se-helical kanye nomsebenzi ophansi wezingxenye zamaketanga.Umthamo we-crystallization wezinto ze-polymer uhlobene eduze nomsebenzi weketanga lamangqamuzana kanye nomthamo we-nucleation.Enkambweni yokupholisa yokubunjwa okujwayelekile kokucubungula, iwindi lokushisa elifanele i-crystallization lincane kakhulu, ukuze i-crystallinity yomkhiqizo wokugcina ibe yincane futhi izinga lokushisa lokushisa elishisayo liphansi.
Ukuguqulwa kwe-Nucleation kuyindlela ephumelelayo yokwandisa i-crystallinity ye-PLA, ukusheshisa izinga le-crystallization, ukuthuthukisa impahla ye-crystallization futhi ngaleyo ndlela kwandise ukumelana nokushisa kwe-PLA.Ngakho-ke, ukuguqulwa kwezinto ze-PLA ezifana ne-nucleation, ukwelashwa kokushisa kanye ne-crosslinking kunendima ebalulekile ekwandiseni uhla lwezicelo zemikhiqizo ye-PLA ngokwandisa izinga lokushisa lokuguquguquka okushisayo nokuthuthukisa ukumelana nokushisa.
Ama-nucleating agents ahlukaniswe ama-nucleating agents angaphili kanye nama-organic nucleating agents.I-inorganic nucleating agents ikakhulukazi ihlanganisa ama-phyllosilicates, i-hydroxyapatite kanye nokuphuma kwayo, izinto zekhabhoni namanye ama-nanoparticles angaphili.Ubumba olunye uhlobo lwezimbiwa ze-silicate ezinezingqimba ezivame ukusetshenziswa ekuguqulweni kwe-PLA, phakathi kwayo i-montmorillonite emele kakhulu.Ama-agent ayinhloko we-organic nucleating yilezi: ama-amide compounds, ama-bisylhydrazides nama-biureas, ama-biomass amancane ama-molecule, i-organometallic phosphorus/phosphonate ne-polyhedral oligosiloxy.
Ukwengezwa kwezithasiselo eziyinkimbinkimbi ze-nucleating ukuze kuthuthukiswe ukuzinza kwayo kokushisa kungcono kunokwengezwa okukodwa.Ifomu eliyinhloko lokuwohloka kwe-PLA i-hydrolysis ngemva kwe-hygroscopic, ngakho-ke indlela yokuxubha i-melt ingasetshenziswa futhi, ukwengeza uwoyela we-hydrophobic additive dimethylsilicone ukunciphisa impahla ye-hygroscopic, ukwengeza izithasiselo ze-alkaline ukunciphisa izinga lokuwohloka kwe-PLA ngokushintsha inani le-PH ye-PLA.
Isikhathi sokuthumela: Nov-07-2022