Tam sim no peb siv cov ntaub ntawv ntim zaj duab xis hloov tau yooj yim, feem ntau yog cov khoom tsis-degradable. Txawm hais tias ntau lub teb chaws thiab kev lag luam tau cog lus rau kev tsim cov khoom siv degradable, tab sis cov khoom siv degradable uas tuaj yeem siv rau kev ntim khoom yooj yim tseem tsis tau hloov los ntawm kev tsim khoom loj. Nrog rau lub teb chaws txoj kev xav txog kev tiv thaiv ib puag ncig, ntau lub xeev thiab lub nroog tau tshaj tawm cov kev txwv yas lossis txawm tias nyob hauv qee thaj chaw ntawm "txoj cai txwv txiav yas. Yog li ntawd, rau cov lag luam ntim tau yooj yim, kev nkag siab zoo ntawm cov ntaub ntawv degradable, yog kev siv cov ntaub ntawv degradable zoo, kom ua tiav cov ntim ntim ntsuab ntsuab.
Yas degradation yog hais txog ib puag ncig tej yam kev mob (kub, humidity, ya raws, oxygen, thiab lwm yam), nws cov qauv muaj cov kev hloov tseem ceeb, kev ua haujlwm poob.
Cov txheej txheem degradation raug cuam tshuam los ntawm ntau yam ib puag ncig. Raws li nws cov txheej txheem degradation, cov yas degradable tuaj yeem muab faib ua cov yas photodegradable, biodegradable plastics, photobiodegradable plastics thiab tshuaj degradable plastics. Biodegradable plastics tuaj yeem muab faib ua tiav biodegradable plastics thiab tsis tiav biodestructive plastics.
1. Photodegradable yas
Photodegradable yas hais txog cov khoom yas hauv lub hnub ci tawg tawg cov tshuaj tiv thaiv, kom cov khoom nyob rau hauv tshav ntuj tom qab lub sij hawm ntawm lub sij hawm poob txhua yam muaj zog, ua hmoov, ib co yuav ua tau ntxiv microbial decomposition, mus rau hauv lub ntuj ecological voj voog. Hauv lwm lo lus, tom qab cov saw hlau molecular ntawm photodegradable yas raug rhuav tshem los ntawm cov txheej txheem photochemical, cov yas yuav poob nws tus kheej lub zog thiab embrittlement, thiab tom qab ntawd dhau los ua hmoov los ntawm corrosion ntawm xwm, nkag mus rau hauv av, thiab rov nkag mus rau hauv lub voj voog lom neeg hauv qab. kev ua ntawm microorganisms.
2. Biodegradable plastics
Biodegradation feem ntau txhais tau tias: biodegradation yog hais txog cov txheej txheem ntawm kev hloov tshuaj lom neeg ntawm cov tshuaj los ntawm kev ua ntawm cov enzymes lom lossis tshuaj degradation uas tsim los ntawm cov kab mob. Hauv cov txheej txheem no, photodegradation, hydrolysis, oxidative degradation thiab lwm yam kev cuam tshuam kuj tshwm sim.
Biodegradable yas mechanism yog: los ntawm cov kab mob los yog hydrolase polymer cov ntaub ntawv rau carbon dioxide, methane, dej, mineralized inorganic ntsev thiab tshiab yas. Hauv lwm lo lus, biodegradable plastics yog cov yas uas degrade los ntawm kev ua ntawm cov kab mob tshwm sim xws li kab mob, pwm (fungi) thiab algae.
Cov yas zoo tshaj plaws biodegradable yog ib yam khoom siv polymer nrog kev ua haujlwm zoo, uas tuaj yeem ua tiav los ntawm ib puag ncig cov kab mob thiab thaum kawg dhau los ua ib feem ntawm cov pa roj carbon monoxide. Ntawd yog, qhov decomposition mus rau qib tom ntej ntawm cov molecules tuaj yeem ntxiv decomposed lossis absorbed los ntawm cov kab mob ntuj, thiab lwm yam.
Lub hauv paus ntsiab lus ntawm biodegradation tau muab faib ua ob chav kawm: ua ntej, muaj biophysical degradation, thaum microbial nres tom qab yaig ntawm cov ntaub ntawv polymer, vim kev loj hlob ntawm cov roj ntsha nyias ua polymer Cheebtsam hydrolysis, ionization los yog protons thiab faib mus rau hauv daim ntawm oligomer, molecular. Cov qauv ntawm cov polymer yog hloov tsis tau, lub polymer biophysical muaj nuj nqi ntawm cov txheej txheem degradation. Hom thib ob yog biochemical degradation, vim yog kev ua haujlwm ncaj qha ntawm cov kab mob lossis cov enzymes, cov polymer decomposition lossis oxidative degradation rau hauv me me molecules, kom txog rau thaum kawg decomposition ntawm carbon dioxide thiab dej, hom degradation no belongs rau biochemical degradation hom.
2. Biodestructive degradation ntawm yas
Biodestructive degradable plastics, tseem hu ua lub cev qhuav dej, yog cov txheej txheem sib xyaw ntawm biodegradable polymers thiab cov khoom siv dav dav, xws li cov hmoov txhuv nplej siab thiab polyolefin, uas tau muab tso rau hauv ib daim ntawv thiab tsis yog degraded tag nrho nyob rau hauv ib puag ncig ntuj thiab tej zaum yuav ua rau cov pa phem thib ob.
3. Ua tiav biodegradable plastics
Raws li lawv cov peev txheej, muaj peb hom biodegradable plastics tag nrho: polymer thiab nws cov derivatives, microbial hluavtaws polymer thiab tshuaj hluavtaws polymer. Tam sim no, hmoov txhuv nplej siab yog cov khoom siv dav siv ntau tshaj plaws hauv kev ntim khoom.
4. Ntuj biodegradable yas
Natural biodegradable plastics xa mus rau natural polymer plastics, uas yog biodegradable cov ntaub ntawv npaj los ntawm tej yam ntuj tso polymer cov ntaub ntawv xws li hmoov txhuv nplej siab, cellulose, chitin thiab protein. Cov khoom no los ntawm ntau qhov chaw, tuaj yeem ua tiav biodegradable, thiab cov khoom muaj kev nyab xeeb thiab tsis muaj tshuaj lom.
Raws li kev degradation ntawm ntau txoj kev, nrog rau ntau qhov chaw ntawm kev thov, tam sim no peb xav tau tus neeg siv khoom tus kheej ntawm biodegradable cov ntaub ntawv yog degradation tag nrho, degradation thiab landfill los yog compost, xav tau cov khoom yas uas twb muaj lawm degradation rau cov ntaub ntawv xws li carbon dioxide, dej. thiab mineralized inorganic ntsev, tuaj yeem yooj yim nqus los ntawm xwm lossis rov ua dua tshiab los ntawm xwm.
Post lub sij hawm: Lub Xya hli ntuj-14-2022