PLA khoom yog dab tsi

PLA khoom yog dab tsi?

Polylactic acid, tseem hu ua PLA, yog ib qho thermoplastic monomer muab tau los ntawm cov khoom siv txuas ntxiv, cov organic xws li pob kws hmoov nplej los yog qab zib.Siv cov peev txheej biomass ua rau PLA ntau lawm sib txawv ntawm cov yas feem ntau, uas yog tsim los ntawm fossil fuels los ntawm distillation thiab polymerization ntawm roj av.

Txawm hais tias muaj qhov sib txawv ntawm cov khoom siv raw, PLA tuaj yeem tsim tau siv tib yam khoom xws li petrochemical plastics, ua rau cov txheej txheem tsim PLA kuj raug nqi.PLA yog qhov thib ob feem ntau tsim bioplastic (tom qab cov hmoov txhuv nplej siab thermoplastic) thiab muaj cov yam ntxwv zoo sib xws rau polypropylene (PP), polyethylene (PE), los yog polystyrene (PS), zoo li biodegradeable.

Lub koom haum ntawm biodegradable cov ntaub ntawv tau tshaj tawm tias PLA cov ntaub ntawv muaj kev cia siab rau kev thov zoo hauv kev ntim khoom, tab sis nws tsis zoo tag nrho hauv toughness, kub tsis kam, antibacterial thiab barrier zog.Thaum siv rau kev thauj mus los ntim, ntim tshuaj tua kab mob thiab kev ntim khoom ntse nrog cov kev xav tau siab rau cov khoom no, nws yuav tsum tau ua kom zoo dua ntxiv.Yuav ua li cas txog kev thov PLA hauv kev ntim khoom?Qhov zoo thiab kev txwv yog dab tsi?

Cov kev tsis txaus ntawm PLA no tuaj yeem raug kho los ntawm copolymerization, blending, plasticization thiab lwm yam kev hloov kho.Ntawm qhov chaw khaws cov pob tshab thiab degradable zoo ntawm PLA, nws tuaj yeem txhim kho qhov degradability, toughness, kub tsis kam, barrier, conductivity thiab lwm yam khoom ntawm PLA, txo cov nqi tsim khoom, thiab ua rau nws siv ntau hauv ntim.
Cov xov xwm no qhia txog kev tshawb fawb txog kev hloov kho PLA siv hauv kev ntim khoom
1. Degradability

PLA nws tus kheej yog qhov ruaj khov ntawm chav tsev kub, tab sis nws yog ib qho yooj yim rau degrade sai nyob rau hauv me ntsis kub ib puag ncig, acid-base ib puag ncig los yog microbial ib puag ncig.Cov yam ntxwv cuam tshuam rau qhov degradation ntawm PLA suav nrog qhov hnyav molecular, crystalline xeev, microstructure, ib puag ncig kub thiab av noo, pH tus nqi, lub sijhawm teeb pom kev zoo thiab cov kab mob ib puag ncig.

Thaum siv rau ntim, lub voj voog degradation ntawm PLA tsis yooj yim los tswj.Piv txwv li, vim nws qhov degradability, PLA ntim feem ntau yog siv rau hauv ntim khoom noj rau lub sijhawm luv.Yog li ntawd, nws yog ib qho tsim nyog los tswj tus nqi degradation los ntawm doping lossis sib tov lwm cov ntaub ntawv hauv PLA raws li cov khoom lag luam ncig ib puag ncig thiab txee lub neej, kom ntseeg tau tias cov khoom ntim tuaj yeem tiv thaiv kev nyab xeeb hauv lub sijhawm siv tau thiab degraded hauv lub sij hawm tom qab tso tseg.

2. Barrier kev ua tau zoo

Barrier yog lub peev xwm los thaiv kev sib kis ntawm cov pa roj thiab dej vapor, tseem hu ua ya raws thiab roj tsis kam.Barrier yog qhov tseem ceeb tshwj xeeb rau kev ntim khoom noj.Piv txwv li, lub tshuab nqus tsev ntim, ntim ntim thiab hloov pauv huab cua ntim txhua qhov yuav tsum tau muaj kev thaiv cov ntaub ntawv kom zoo li sai tau;Kev tswj hwm huab cua khaws cia ntawm cov txiv hmab txiv ntoo tshiab thiab zaub yuav tsum muaj qhov sib txawv ntawm cov khoom siv rau cov pa roj xws li oxygen thiab carbon dioxide;Cov ntaub ntawv pov thawj noo noo yuav tsum muaj dej noo zoo ntawm cov ntaub ntawv;Kev ntim tshuaj tiv thaiv xeb xav kom cov khoom siv tuaj yeem thaiv cov roj thiab ya raws.

Piv nrog rau cov nylon barrier siab thiab polyvinylidene chloride, PLA muaj cov pa tsis zoo thiab dej vapor barrier.Thaum siv rau ntim, nws muaj kev tiv thaiv tsis txaus rau cov zaub mov oily.

3. Thaum tshav kub kub tsis kam
Cov cua kub tsis zoo ntawm cov khoom siv PLA yog vim nws qeeb crystallization tus nqi thiab qis crystallinity.Lub thermal deformation kub ntawm amorphous PLA tsuas yog hais txog 55 ℃.Lub unmodified polylactic acid straw muaj cov cua sov tsis zoo.Yog li ntawd, PLA straw yog tsim nyog rau cov dej sov thiab txias, thiab qhov kam rau siab kub yog - 10 ℃ to 50 ℃.

Txawm li cas los xij, hauv kev siv tswv yim, cov quav cab ntawm cov mis nyuj tshuaj yej haus thiab kas fes nplawm pas nrig yuav tsum tau ua kom tau raws li qhov ntsuas kub ntawm 80 ℃.Qhov no yuav tsum tau hloov kho raws li qhov qub, uas tuaj yeem hloov pauv cov khoom ntawm PLA los ntawm ob yam: kev hloov kho lub cev thiab tshuaj lom neeg.Ntau qhov sib xyaw ua ke, cov saw txuas ntxiv thiab kev sib xyaw ua ke, inorganic filling thiab lwm yam thev naus laus zis tuaj yeem siv los hloov cov cua sov tsis zoo ntawm PLA nws tus kheej thiab rhuav tshem cov txheej txheem ntawm PLA straw khoom.

Qhov kev ua tau zoo tshwj xeeb yog tias cov ceg saw ntev ntawm PLA tuaj yeem tswj tau los ntawm kev hloov pauv pub piv ntawm PLA thiab tus neeg sawv cev nucleating.Qhov ntev ntawm ceg saw, qhov hnyav dua molecular, qhov ntau dua TG, qhov rigidity ntawm cov khoom yog txhim khu kev qha thiab thermal stability yog txhim khu kev qha, thiaj li los txhim kho lub tshav kub tsis kam ntawm PLA thiab inhibit qhov thermal degradation tus cwj pwm ntawm PLA.