I-PLA, i-biodegradable material, yi-semi-crystalline polymer enobushushu obunyibilikayo ukuya kwi-180℃.Ke kutheni le nto imathiriyeli imbi kakhulu ekuxhathiseni ubushushu xa sele yenziwe?
Isizathu esona sizathu kukuba izinga le-crystallization ye-PLA licotha kwaye i-crystallinity yemveliso iphantsi kwinkqubo yokucubungula okuqhelekileyo kunye nokubumba.Ngokumalunga nokwakheka kweekhemikhali, i-molecular chain ye-PLA iqulethe -CH3 kwi-athomu ye-chiral carbon, enesakhiwo esiqhelekileyo se-helical kunye nomsebenzi ophantsi wamacandelo ekhonkco.Umthamo wekristali wezinto zepolymer uhambelana ngokusondeleyo nomsebenzi wekhonkco lemolekyuli kunye nomthamo we-nucleation.Kwinkqubo yokupholisa yokubunjwa kwenkqubo eqhelekileyo, iwindow yokushisa efanelekile kwi-crystallization incinci kakhulu, ukwenzela ukuba i-crystallinity yemveliso yokugqibela incinci kwaye ukushisa kwe-thermal deformation kuphantsi.
Ukuguqulwa kwe-Nucleation yindlela esebenzayo yokunyusa i-crystallinity ye-PLA, ukukhawulezisa izinga le-crystallization, ukuphucula ipropathi ye-crystallization kwaye ngaloo ndlela ukwandisa ukumelana nokushisa kwe-PLA.Ngoko ke, ukuguqulwa kwezinto ze-PLA ezifana ne-nucleation, unyango lobushushu kunye ne-crosslinking kunendima ebalulekileyo ekwandiseni uluhlu lwezicelo zeemveliso ze-PLA ngokunyusa ukushisa kwe-thermal deformation kunye nokuphucula ukuxhathisa ukushisa.
Ii-agent ze-Nucleating zohlulwe kwii-agent ze-nucleating ze-inorganic kunye ne-organic nucleating agents.I-inorganic nucleating agents ikakhulu ibandakanya i-phyllosilicates, i-hydroxyapatite kunye ne-derivatives yayo, izinto zekhabhoni kunye nezinye i-nanoparticles ezingenayo.Udongwe lolunye uhlobo lwezixhobo zezimbiwa ze-silicate ezidla ngokusetyenziswa kwi-PLA ukuguqulwa, phakathi kwayo i-montmorillonite imele kakhulu.Ii-agent eziphambili ze-nucleating ze-organic zezi: i-amide compounds, i-bisylhydrazides kunye ne-biureas, i-biomass iimolekyuli ezincinci, i-organometallic phosphorus / phosphonate kunye ne-polyhedral oligosiloxy.
Ukongezwa kwee-additives ze-nucleating eziyinkimbinkimbi ukuphucula ukuzinza kwayo kwe-thermal kungcono kunezongezo zodwa.Uhlobo oluphambili lokuthotywa kwe-PLA luyi-hydrolysis emva kwe-hygroscopic, ngoko ke indlela yokudibanisa i-melt ingasetyenziselwa, ukongeza i-hydrophobic additive dimethylsilicone ioli yokunciphisa ipropati ye-hygroscopic, ukongeza izongezo ze-alkaline ukunciphisa izinga lokuthotywa kwe-PLA ngokuguqula ixabiso le-PH ye-PLA.
Ixesha lokuposa: Nov-07-2022