Kusukela ukuvinjelwa kwepulasitiki, izinto ezibolayo ezibolayo seziphenduke indawo entsha eshisayo, amabhizinisi amakhulu andise ukukhiqizwa, ama-oda akhuphuka ngasikhathi sinye nawo abangela ukuhlinzekwa kwezinto ezingavuthiwe, ikakhulukazi i-PBAT, i-PBS nezinye izinto zesikhwama se-membrane ezonakele ezinyangeni ezi-4 nje, intengo yakhuphuka.Ngakho-ke, impahla ye-PLA enenani elizinzile idonse ukunaka.
I-Poly (lactic acid) (PLA), eyaziwa nangokuthi i-poly (lactide), iyi-polymer entsha evumelana nemvelo etholwe ngokuvula i-polymerization ye-lactic acid elungiswe ngesitashi sombila esisekelwe kubhayoloji, futhi ingacekelwa phansi ngokuphelele ingabi nemvelo. imikhiqizo yokugcina, njenge-CO2 ne-H2O.
Ngenxa yezinzuzo zayo zamandla aphezulu emishini, ukucutshungulwa kalula, indawo ephezulu yokuncibilika, ukubola kwe-biodegradability kanye ne-biocompatibility enhle, iye yasetshenziswa kabanzi kwezolimo, ukupakisha ukudla, ukunakekelwa kwezokwelapha kanye neminye imikhakha.I-PLA straw ewohlokayo ithole ukunakwa kakhulu eminyakeni yamuva.
Ukuphendula umyalo wokuvinjelwa kwepulasitiki, izitsha zephepha zisetshenziswa kakhulu eChina.Kodwa-ke, ama-straw straws agxekwa kakhulu ngomuzwa wabo ongemuhle wokusetshenziswa.Abakhiqizi abaningi ngokwengeziwe baqala ukukhetha izinto eziguquliwe ze-PLA ukwenza utshani.
Nokho, nakuba i-polylactic acid inezakhiwo ezisebenza kahle, ubude bayo obuphansi ngesikhathi sekhefu (imvamisa ingaphansi kuka-10%) kanye nokuqina okungenamandla kunciphisa ukusetshenziswa kwayo ezitshalweni.
Ngakho-ke, ukuqina kwe-PLA sekuphenduke isihloko esishisayo socwaningo okwamanje.Okulandelayo yinqubekelaphambili yamanje yocwaningo oluqinisayo lwe-PLA.
I-Poly - lactic acid (PLA) ingenye yamapulasitiki avuthwe kakhulu abolayo.Izinto zayo ezingavuthiwe zisuka emiculweni yezitshalo evuselelekayo, ummbila, imikhiqizo yezolimo, njll., futhi inokubola okuhle kwe-biodegradability.I-PLA inezakhiwo ezinhle kakhulu zemishini, efana nepulasitiki ye-polypropylene, futhi ingangena esikhundleni sepulasitiki ye-PP ne-PET kwezinye izinkambu.Phakathi naleso sikhathi, i-PLA inokucwebezela okuhle, ukukhanya, ukuzwa kwesandla kanye nezakhiwo ezithile zokulwa namagciwane
Isimo sokukhiqiza se-PLA
Njengamanje, i-PLA inemizila emibili yokwenziwa.Enye i-condensation polymerization, okungukuthi i-lactic acid iphelelwa amanzi emzimbeni futhi ijiya ngaphansi kwezinga lokushisa eliphezulu kanye nengcindezi ephansi.Inqubo yokukhiqiza ilula futhi izindleko ziphansi, kodwa isisindo samangqamuzana omkhiqizo asilingani, futhi umphumela wokufaka isicelo awulungile.
Enye indandatho ye-lactide - ukuvula i-polymerization, okuyindlela yokukhiqiza evamile.
Ukuwohloka kwe-PLA
I-PLA izinzile uma kuqhathaniswa nezinga lokushisa elilingana negumbi, kodwa incipha kalula ibe yi-CO2 namanzi endaweni yokushisa ethe ukukhuphuka kancane, endaweni ene-acid-base kanye nemvelo yamagciwane.Ngakho-ke, imikhiqizo ye-PLA ingasetshenziswa ngokuphepha phakathi nesikhathi sokuqinisekisa futhi incishwe ngesikhathi ngemuva kokulahlwa ngokulawula imvelo nokupakisha.
Izici ezithinta ukuwohloka kwe-PLA ikakhulukazi zifaka isisindo samangqamuzana, isimo sekristalu, i-microstructure, izinga lokushisa elizungezile kanye nomswakama, inani le-pH, isikhathi sokukhanya kanye nama-microorganisms emvelo.
I-PLA nezinye izinto zingathinta izinga lokuwohloka.
Isibonelo, i-PLA enezela inani elithile likafulawa wezinkuni noma i-corn stalk fiber ingasheshisa kakhulu izinga lokuwohloka.
Ukusebenza kwesithiyo se-PLA
I-insulation isho ikhono lempahla ukuvimbela ukudlula kwegesi noma umhwamuko wamanzi.
Impahla yokuvimbela ibaluleke kakhulu ezintweni zokupakisha.Njengamanje, isikhwama sepulasitiki esonakele kakhulu emakethe siyinhlanganisela ye-PLA/PBAT.
Izici zokuvimbela ifilimu ye-PLA ethuthukisiwe inganweba inkambu yohlelo lokusebenza.
Izici ezithinta impahla yokuvimbela i-PLA ikakhulukazi zihlanganisa izici zangaphakathi (isakhiwo samangqamuzana nesimo se-crystallization) nezici zangaphandle (izinga lokushisa, umswakama, amandla angaphandle).
1. Ifilimu yokushisisa ye-PLA izonciphisa impahla yayo yokuvimbela, ngakho i-PLA ayifanele ukupakishwa kokudla okudinga ukushiswa.
2. Ukwelula i-PLA ebangeni elithile kungakhuphula impahla yokuvimbela.
Lapho isilinganiso se-tensile sikhuphuka sisuka ku-1 siye ku-6.5, i-crystallinity ye-PLA ikhuphuka kakhulu, ngakho-ke impahla yokuvimbela iyathuthukiswa.
3. Ukwengeza izithiyo ezithile (njengobumba nefayibha) ku-PLA matrix kungathuthukisa impahla yokuvimbela i-PLA.
Lokhu kungenxa yokuthi isithiyo sandisa indlela egobile yenqubo yamanzi noma yegesi yokungena kuma-molecule amancane.
4. Ukwelashwa kwe-coating ebusweni befilimu ye-PLA kungathuthukisa impahla yokuvimbela.
Isikhathi sokuthumela: 29-10-21