Ukusukela ekuvinjweni kweplastiki, izinto eziguquguqukayo ze-biodegradable ziye zaba yindawo entsha eshushu, amashishini amakhulu aye andisa imveliso, ii-odolo zanda ngaxeshanye nazo zabangela ukubonelelwa kwezinto ezikrwada, ngakumbi i-PBAT, i-PBS kunye nezinye izixhobo zebhegi ezonakalisayo kwiinyanga nje ze-4, ixabiso lenyuka. Ke ngoko, izinto zePLA ezinexabiso elizinzileyo ziye zatsala ingqalelo.
I-Poly (lactic acid) (PLA), ekwaziwa ngokuba yi-poly (lactide), yinto entsha yepolymer ehambelana nokusingqongileyo efunyenwe ngokuvula i-ring-opening polymerization ye-lactic acid elungiswe kwi-biologically-based corn starch, kwaye inokuthotywa ngokupheleleyo ibe yinto ehambelana nokusingqongileyo. iimveliso zokuphela, ezifana CO2 kunye H2O.
Ngenxa yeenzuzo zayo zamandla omatshini aphezulu, ukusetyenzwa ngokulula, indawo ephezulu yokunyibilika, ukubola kwezinto eziphilayo kunye ne-biocompatibility efanelekileyo, isetyenziswe ngokubanzi kwezolimo, ukupakishwa kokutya, ukhathalelo lwezonyango kunye nezinye iinkalo. I-PLA eyonakaliswayo indiza ifumene eyona ngqalelo kwiminyaka yakutshanje.
Ukuphendula kumyalelo wokuvalwa kweplastiki, iindiza zephepha zisetyenziswa kakhulu eTshayina. Nangona kunjalo, izitro zephepha zigxekwa ngokubanzi ngenxa yokuziva zingasebenzi kakuhle. Bayanda abavelisi baqala ukukhetha izixhobo ezilungisiweyo zePLA ukwenza iindiza.
Nangona kunjalo, nangona i-asidi ye-polylactic ineempawu zoomatshini, ubude bayo obuphantsi ngexesha lokuphumla (ngokuqhelekileyo ngaphantsi kwe-10%) kunye nokuqina okungahambi kakuhle kuyanciphisa ukusetyenziswa kwayo kwizitro.
Ke ngoko, ukuqina kwe-PLA kuye kwaba sisihloko sophando esishushu ngoku. Oku kulandelayo yinkqubela yangoku ye-PLA yophando olunzima.
I-Poly – lactic acid (PLA) yenye yeeplastiki ezivuthwa kakhulu ezinokonakala. Izinto zayo ezikrwada zisuka kwimicu yezityalo ezivuselelekayo, umbona, imveliso yezolimo, njl. I-PLA inezakhiwo ezigqwesileyo zomatshini, ezifana neeplastiki zepolypropylene, kwaye ingathatha indawo yePP kunye neeplastiki zePET kwezinye iindawo. Okwangoku, i-PLA ineglosi elungileyo, ukucaca, ukuvakalelwa kwesandla kunye neempawu ezithile zokulwa ne-antibacterial
Ubume bemveliso ye-PLA
Okwangoku, i-PLA ineendlela ezimbini zokwenziwa. Enye yi-condensation polymerization, okt iasidi ye-lactic iphelelwe ngamanzi kwaye ixinaniswe phantsi kobushushu obuphezulu kunye noxinzelelo oluphantsi. Inkqubo yokuvelisa ilula kwaye ixabiso liphantsi, kodwa ubunzima be-molecular yemveliso ayilingani, kwaye umphumo wesicelo osebenzayo ubi.
Enye i-lactide ring - ukuvula i-polymerization, eyona ndlela yokuvelisa imveliso.
Ukuthotywa kwePLA
I-PLA izinzile kwiqondo lobushushu begumbi, kodwa ithotywa ngokulula kwi-CO2 kunye namanzi kwindawo yobushushu obuphezulu kancinane, imeko-bume ye-asidi kunye ne-microbial. Ke ngoko, iimveliso ze-PLA zinokusetyenziswa ngokukhuselekileyo ngaphakathi kwexesha elisemthethweni kwaye zithotywe ngexesha elifanelekileyo emva kokulahlwa ngokulawula indawo kunye nokupakisha.
Izinto ezichaphazela ukuthotywa kwePLA ikakhulu zibandakanya ubunzima bemolekyuli, imeko yekristale, i-microstructure, ubushushu obuphakathi kunye nokufuma, ixabiso le-pH, ixesha lokukhanyisa kunye ne-microorganisms yokusingqongileyo.
I-PLA kunye nezinye izinto ezinokuchaphazela izinga lokuthotywa.
Umzekelo, i-PLA yongeza inani elithile lomgubo womthi okanye i-corn stalk fiber inokukhawulezisa kakhulu izinga lokuthotywa.
Ukusebenza komqobo we-PLA
I-Insulation ibhekiselele kwisakhono sesixhobo sokuthintela ukudlula kwerhasi okanye umphunga wamanzi.
Ipropati yomqobo ibaluleke kakhulu kwizinto zokupakisha. Okwangoku, eyona ixhaphakileyo ingxowa yeplastiki eyonakalayo kwimarike yi-PLA/PBAT imathiriyeli ehlanganisiweyo.
Iipropati zomqobo zefilimu ye-PLA ephuculweyo inokwandisa indawo yesicelo.
Izinto ezichaphazela ipropati yokuthintela i-PLA ikakhulu ziquka izinto zangaphakathi (isakhiwo se-molecular kunye ne-crystallization state) kunye nezinto zangaphandle (ubushushu, umswakama, amandla angaphandle).
1. Ukufudumeza ifilimu ye-PLA kuya kunciphisa ipropati yomqobo, ngoko i-PLA ayifanelekanga ukupakishwa kokutya okudinga ukufudumeza.
2. Ukwelula i-PLA kuluhlu oluthile kunokunyusa ipropati yomqobo.
Xa umlinganiselo we-tensile unyuswa ukusuka kwi-1 ukuya kwi-6.5, i-crystallinity ye-PLA yanda kakhulu, ngoko ke ipropati yomqobo iphuculwe.
3. Ukongeza ezinye izithintelo (ezifana nodongwe kunye nefiber) kwi-PLA matrix inokuphucula ipropati yokuthintela i-PLA.
Oku kungenxa yokuba umqobo wandisa indlela egobileyo yamanzi okanye inkqubo yokungena kwegesi kwiimolekyuli ezincinci.
4. Unyango lwe-Coating ebusweni befilimu ye-PLA inokuphucula ipropati yomqobo.
Ixesha lokuthumela: 29-10-21