Txij li kev txwv tsis pub siv cov yas, cov khoom siv biodegradable tau dhau los ua qhov chaw kub kub tshiab, cov tuam txhab loj tau nthuav dav ntau lawm, kev txiav txim siab tau nce tib lub sijhawm kuj ua rau cov khoom siv raw, tshwj xeeb tshaj yog PBAT, PBS thiab lwm yam khoom siv degradable membrane hnab hauv tsuas yog 4 lub hlis, tus nqi nce. Yog li ntawd, cov khoom siv PLA nrog tus nqi ruaj khov tau nyiam.
Poly (lactic acid) (PLA), tseem hu ua poly (lactide), yog ib puag ncig-phooj ywg polymer cov khoom tau los ntawm lub nplhaib-qhib polymerization ntawm lactic acid npaj los ntawm biologically-based pob kws hmoov txhuv nplej siab, thiab tuaj yeem degraded tag nrho rau hauv ib puag ncig tus phooj ywg. cov khoom kawg, xws li CO2 thiab H2O.
Vim nws qhov zoo ntawm kev siv tshuab muaj zog, kev ua haujlwm yooj yim, siab melting point, biodegradability thiab biocompatibility zoo, nws tau siv dav hauv kev ua liaj ua teb, ntim khoom noj, kev kho mob thiab lwm yam haujlwm. PLA degradable straw tau txais kev pom zoo tshaj plaws hauv xyoo tas los no.
Nyob rau hauv teb rau kev txiav npluav yas, ntawv straws yog dav siv nyob rau hauv Suav teb. Txawm li cas los xij, cov ntawv straws tau raug thuam ntau rau lawv txoj kev siv tsis zoo. Ntau thiab ntau lub tuam txhab pib xaiv PLA hloov cov ntaub ntawv los tsim cov straws.
Txawm li cas los xij, txawm hais tias polylactic acid muaj cov khoom siv zoo, nws qhov elongation qis thaum tawg (feem ntau tsawg dua 10%) thiab cov tawv tawv tsis zoo txwv nws daim ntawv thov hauv straws.
Yog li, PLA toughening tau dhau los ua cov ntsiab lus tshawb fawb kub tam sim no. Cov hauv qab no yog qhov kev nce qib tam sim no ntawm PLA kev tshawb fawb toughening.
Poly - lactic acid (PLA) yog ib qho ntawm cov yas biodegradable uas paub tab. Nws cov ntaub ntawv raw yog los ntawm cov nroj tsuag txuas ntxiv dua tshiab, pob kws, cov khoom ua liaj ua teb, thiab lwm yam, thiab nws muaj biodegradability zoo. PLA muaj cov khoom siv zoo heev, zoo ib yam li cov yas polypropylene, thiab tuaj yeem hloov PP thiab PET yas hauv qee qhov chaw. Lub caij no, PLA muaj qhov zoo gloss, pob tshab, tes xav thiab qee yam tshuaj tua kab mob
PLA ntau lawm txheej xwm
Tam sim no, PLA muaj ob txoj kev siv hluavtaws. Ib qho yog ncaj qha condensation polymerization, piv txwv li lactic acid yog ncaj qha lub cev qhuav dej thiab condensed nyob rau hauv qhov kub thiab txias. Cov txheej txheem ntau lawm yog qhov yooj yim thiab tus nqi qis, tab sis qhov hnyav molecular ntawm cov khoom tsis sib xws, thiab cov txiaj ntsig ntawm daim ntawv thov tsis zoo.
Lwm qhov yog lub nplhaib lactide - qhib polymerization, uas yog hom kev tsim khoom loj.
Degradability ntawm PLA
PLA yog qhov ruaj khov ntawm chav tsev kub, tab sis yooj yim degrades rau CO2 thiab dej hauv qhov kub thiab txias me ntsis, ib puag ncig acid-base thiab microbial ib puag ncig. Yog li ntawd, cov khoom siv PLA tuaj yeem siv tau zoo nyob rau lub sijhawm siv tau thiab ua kom lub sijhawm degraded tom qab muab pov tseg los ntawm kev tswj hwm ib puag ncig thiab ntim khoom.
Cov yam ntxwv cuam tshuam rau PLA degradation feem ntau suav nrog qhov hnyav molecular, crystalline xeev, microstructure, ambient kub thiab av noo, pH tus nqi, lub sij hawm illumination thiab ib puag ncig cov kab mob.
PLA thiab lwm yam ntaub ntawv tuaj yeem cuam tshuam tus nqi degradation.
Piv txwv li, PLA ntxiv ib qho ntawm cov hmoov nplej los yog pob kws stalk fiber ntau tuaj yeem ua rau kom tus nqi degradation.
PLA barrier kev ua tau zoo
Rwb thaiv tsev hais txog lub peev xwm ntawm cov khoom siv los tiv thaiv kev kis ntawm cov pa roj lossis dej vapor.
Cov cuab yeej barrier tseem ceeb heev rau cov khoom ntim khoom. Tam sim no, cov hnab yas degradable tshaj plaws ntawm kev ua lag luam yog PLA / PBAT cov khoom sib xyaw.
Cov khoom pov thawj ntawm kev txhim kho PLA zaj duab xis tuaj yeem nthuav dav hauv daim ntawv thov.
Cov yam ntxwv cuam tshuam rau PLA barrier cov cuab yeej feem ntau suav nrog cov khoom siv sab hauv (cov qauv molecular thiab crystallization xeev) thiab lwm yam (kub, av noo, sab nraud quab yuam).
1. Cua sov PLA zaj duab xis yuav txo nws cov khoom thaiv, yog li PLA tsis haum rau ntim khoom noj uas xav tau cua sov.
2. Stretching PLA nyob rau hauv ib tug tej yam ntau yam yuav ua rau kom lub barrier khoom.
Thaum lub tensile piv yog nce los ntawm 1 mus rau 6.5, lub crystallinity ntawm PLA yog heev nce, yog li cov khoom thaiv kev txhim kho.
3. Ntxiv qee qhov thaiv (xws li av nplaum thiab fiber ntau) rau PLA matrix tuaj yeem txhim kho PLA barrier khoom.
Qhov no yog vim hais tias lub barrier prolongs txoj kev nkhaus ntawm cov dej los yog gas permeation txheej txheem rau me me molecules.
4. Txheej kev kho mob ntawm qhov chaw ntawm PLA zaj duab xis tuaj yeem txhim kho cov khoom thaiv.
Post lub sij hawm: 29-10-21