Biodegradable polymers: lub tswv yim, cov khoom, cov txheej txheem ntawm kev npaj thiab cov piv txwv ntawm cov tshuaj tiv thaiv

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Koj tuaj yeem pom tias dhau kaum xyoo dhau los, cov khoom lag luam nrog cov npe "bio" ntxiv rau lub npe tau txais kev nyiam. Nws yog npaj los qhia tias cov khoom muaj kev nyab xeeb rau tib neeg thiab xwm. Nws yog nquag txhawb los ntawm cov xov xwm. Nws txawm tuaj rau qhov tsis txaus ntseeg - thaum xaiv ib qho dej haus, lawv xav tias biokefir yog qhov zoo tshaj plaws, thiab biofuel tsis yog lwm txoj hauv kev rau roj, tab sis cov khoom lag luam zoo ib puag ncig. Thiab tsis txhob hnov qab txog bio-extracts uas ua rau cov tshuaj pleev ib ce ua haujlwm "miracles".

cov ntaub ntawv dav dav

Tam sim no cia peb mob siab. Feem ntau, txav mus rau hauv txoj kev, koj tuaj yeem pom cov pob tseg tsis tu ncua. Tsis tas li ntawd, muaj tag nrho cov chaw pov tseg uas tib neeg pov tseg. Nws zoo li tsis phem, tab sis muaj ib qho kev rho tawm - lub sij hawm decomposition ntev dhau lawm. Muaj ntau txoj hauv kev los kho qhov no - qhov no yog kev rov ua dua ntawm cov khib nyiab, thiab siv cov khoom siv tsis zoo uas ua rau cov decomposers sai sai. Wb tham txog rooj plaub thib ob.

Muaj ntau lub ntsiab lus ntawm no. Ntim, log tsheb, iav, derivatives ntawm kev lag luam tshuaj. Tag nrho lawv xav tausaib xyuas. Txawm li cas los xij, tsis muaj ib daim ntawv qhia universal. Yog li ntawd, yuav tsum paub tshwj xeeb yog dab tsi thiab yuav ua li cas thiaj li tiv thaiv kev ua qias tuaj ib puag ncig.

Biodegradable polymers tau tsim los ua cov lus teb rau cov teeb meem ntawm kev pov tseg cov yas pov tseg. Nws tsis pub leejtwg paub tias lawv qhov ntim tau loj hlob txhua xyoo. Lo lus biopolymer kuj tseem siv rau lawv cov npe luv. Lawv peculiarity yog dab tsi? Lawv tuaj yeem decompose nyob rau hauv ib puag ncig vim yog kev ua ntawm lub cev thiab cov kab mob - fungi lossis kab mob. Ib lub polymer raug suav hais tias yog tias nws tag nrho cov huab hwm coj tau nqus hauv dej lossis av hauv rau lub hlis. Qhov no ib nrab daws cov teeb meem ntawm pov tseg. Nyob rau tib lub sijhawm, cov khoom decomposition tau txais - dej thiab carbon dioxide. Yog tias muaj lwm yam, ces nws yuav tsum tau tshawb xyuas kom muaj kev nyab xeeb thiab muaj cov tshuaj lom. Lawv kuj tseem tuaj yeem rov ua dua los ntawm cov txheej txheem plastics feem ntau tsim cov thev naus laus zis xws li extrusion, tshuab moulding, thermoforming thiab txhaj tshuaj molding.

peb ua haujlwm dabtsi?

Tau txais biodegradable polymers yog ib txoj haujlwm nyuaj heev. Kev txhim kho cov thev naus laus zis uas ua rau kom tau txais cov ntaub ntawv muaj kev nyab xeeb tau ua tiav hauv Tebchaws Meskas, ntawm Tebchaws Europe, Nyiv, Kaus Lim Qab Teb thiab Tuam Tshoj. Hmoov tsis, nws yuav tsum tau muab sau tseg tias nyob rau hauv Russia cov txiaj ntsig tsis txaus siab. Tsim cov thev naus laus zis rau biodegradation ntawm plastics thiab lawv cov khoom tsim los ntawm cov khoom siv txuas ntxiv dua tshiab yog qhov zoo siab heev. Tsis tas li ntawd, lub teb chaws tseem muaj roj txaus rau kev tsim cov polymers. Tab sis txhua yamtib yam, peb cov lus qhia tseem ceeb tuaj yeem paub qhov txawv:

1. Kev tsim cov biodegradable polyesters raws li hydroxycarboxylic acids.
2. Tsim cov yas raws li cov khoom xyaw ntuj tsim tawm.
3. Industrial polymers ua biodegradable.

Tab sis li cas txog kev xyaum? Cia wb mus saib seb yuav ua li cas biodegradable polymers ua.

YBacterial polyhydroxyalkanoates

Cov kab mob microorganisms feem ntau loj hlob hauv ib puag ncig uas muaj cov pa roj carbon zoo. Hauv qhov no, tsis muaj phosphorus lossis nitrogen. Hauv cov xwm txheej zoo li no, cov kab mob sib xyaw ua ke thiab sib sau polyhydroxyalkanoates. Lawv ua hauj lwm raws li qhov cia ntawm carbons (khoom noj khoom haus) thiab lub zog. Yog tias tsim nyog, lawv tuaj yeem decompose polyhydroxyalkanoates. Cov cuab yeej no yog siv rau kev tsim khoom ntawm cov ntaub ntawv ntawm pab pawg no. Qhov tseem ceeb tshaj plaws rau peb yog polyhydroxy butyrate thiab polyhydroxy valerate. Yog li, cov plastics no yog biodegradable. Tib lub sijhawm, lawv yog aliphatic polyesters resistant rau ultraviolet hluav taws xob.

Nws yuav tsum tau muab sau tseg tias txawm hais tias lawv muaj kev ruaj ntseg txaus nyob rau hauv cov dej ib puag ncig, hiav txwv, av, composting thiab recycling ib puag ncig pab rau lawv cov kev puas tsuaj ntawm cov roj ntsha. Thiab nws tshwm sim sai sai. Piv txwv li, yog hais tias lub compost muaj av noo ntawm 85% thiab 20-60 degrees Celsius, ces decomposition rau carbon dioxide thiab dej yuav siv sij hawm 7-10 lub lis piam. Polyhydroxyalkanoates siv nyob qhov twg?

Lawvyog siv rau kev tsim cov khoom ntim biodegradable thiab cov ntaub ntawv tsis-woven, cov ntaub so ntswg pov tseg, fibers thiab cov yeeb yaj kiab, cov khoom siv tu tus kheej, cov tshuaj tiv thaiv dej rau cov duab los qhia thiab ntawv. Raws li txoj cai, lawv tuaj yeem hla cov pa oxygen, tiv taus cov tshuaj lom neeg, muaj cov txheeb ze thermal stability, thiab muaj zog piv rau polypropylene.

Hais txog qhov tsis zoo ntawm biodegradable polymers, nws yuav tsum raug sau tseg tias lawv kim heev. Ib qho piv txwv yog Biopol. Nws raug nqi 8-10 npaug ntau dua li cov yas yas. Yog li ntawd, nws tsuas yog siv rau hauv cov tshuaj, rau ntim qee cov tshuaj tsw qab thiab cov khoom siv tu tus kheej. Ntau nrov ntawm polyhydroxyalkanoates yog mirel, tau los ntawm saccharified cornstarch. Nws qhov zoo dua yog tus nqi qis. Tab sis, txawm li cas los xij, nws tus nqi tseem yog ob npaug ntawm cov tsoos low-density polyethylene. Nyob rau tib lub sijhawm, cov khoom siv raw khoom suav txog 60% ntawm tus nqi. Thiab cov kev siv zog tseem ceeb yog tsom mus nrhiav nws cov khoom pheej yig. Lub zeem muag hauv nqe lus nug yog cov hmoov txhuv nplej siab xws li nplej, rye, barley.

YPolylactic acid

Kev tsim cov biodegradable polymers rau ntim kuj yog siv los ntawm polylactide. Nws tseem yog polylactic acid. Nws sawv cev li cas? Nws yog linear aliphatic polyester, ib tug condensation khoom ntawm lactic acid. Nws yog monomer los ntawm polylactide yog tsim los ntawm cov kab mob. Nws yuav tsum raug sau tseg tias nws cov khoom tsim nrog kev pab los ntawm cov kab mob yog yooj yim dua li cov txheej txheem ib txwm muaj. Tom qab tag nrho, polylactides yog tsim los ntawm cov kab mob los ntawm muaj suab thaj nyob rau hauv ib tug technologically yooj yim txheej txheem. Lub polymer nws tus kheej yog sib xyaw ntawm ob qho tib si optical isomers nrog tib lub ntsiab lus.

Cov khoom uas tau tshwm sim muaj qhov zoo thermal stability. Yog li, vitrification tshwm sim ntawm qhov kub ntawm 90 degrees Celsius, thaum melting tshwm sim ntawm 210-220 Celsius. Tsis tas li ntawd, polylactide yog UV-resistant, me ntsis flammable, thiab yog hais tias nws hlawv, ces nrog ib tug me me ntawm cov pa luam yeeb. Nws tuaj yeem ua tiav siv txhua txoj kev uas haum rau cov thermoplastics. Cov khoom tau los ntawm polylactide muaj siab rigidity, gloss, thiab pob tshab. Lawv yog siv los ua cov phaj, tais, zaj duab xis, fiber ntau, implants (qhov no yog li cas biodegradable polymers yog siv nyob rau hauv cov tshuaj), ntim rau tshuaj pleev ib ce thiab khoom noj khoom haus, fwj dej, kua txiv, mis nyuj (tab sis tsis carbonated dej qab zib, vim hais tias cov khoom dhau los. carbon dioxide). Ntxiv rau cov ntaub, cov khoom ua si, cov xov tooj ntawm tes thiab cov nas hauv computer. Raws li koj tuaj yeem pom, kev siv biodegradable polymers yog qhov dav heev. Thiab qhov ntawd tsuas yog rau ib pab pawg xwb!

Kev tsim khoom thiab biodegradation ntawm polylactic acid

Thawj zaug, patent rau nws cov khoom tsim tawm rov qab rau xyoo 1954. Tab sis kev lag luam ntawm no bioplastic pib tsuas yog thaum pib ntawm lub xyoo pua 21st - hauv 2002. Txawm hais tias qhov no, twb muaj ntau lub tuam txhab uas koom nrog hauv nws cov khoom siv - tsuas yog hauv Tebchaws Europe muaj ntau dua 30 ntawm lawv. Ib qho txiaj ntsig tseem ceebpolylactic acid yog tus nqi qis - nws twb sib tw yuav luag ntawm qhov sib npaug ntawm cov khoom siv polypropylene thiab polyethylene. Nws yog xav tias twb nyob rau hauv 2020, polylactide yuav muaj peev xwm pib thawb lawv nyob rau hauv lub ntiaj teb no kev ua lag luam. Txhawm rau kom nws biodegradability, hmoov txhuv nplej siab feem ntau ntxiv rau nws. Qhov no kuj muaj txiaj ntsig zoo rau tus nqi ntawm cov khoom. Muaj tseeb, cov khoom sib xyaw ua ke yog qhov tsis yooj yim, thiab cov khoom siv yas, xws li sorbitol lossis glycerin, yuav tsum tau ntxiv rau lawv txhawm rau ua kom cov khoom kawg ua kom zoo dua qub. Lwm txoj hauv kev daws teeb meem yog los tsim cov hlau nrog lwm cov polyesters degradable.

Polylactic acid decomposes hauv ob kauj ruam. Ua ntej, pawg ester yog hydrolyzed nrog dej, ua rau tsim cov lactic acid thiab ob peb lwm cov molecules. Tom qab ntawd lawv decompose nyob rau hauv ib qho chaw nrog kev pab los ntawm microbes. Polylactides raug cov txheej txheem no hauv 20-90 hnub, tom qab ntawd tsuas yog carbon dioxide thiab dej nyob.

Starch hloov kho

Thaum cov khoom siv raw khoom siv, nws yog qhov zoo, vim tias cov peev txheej rau nws txuas ntxiv mus tas li, yog li lawv xyaum tsis txwv. Starch tau txais qhov nrov tshaj plaws hauv qhov no. Tab sis nws muaj qhov tsis zoo - nws muaj peev xwm nqus dej noo. Tab sis qhov no tuaj yeem zam tau yog tias koj pom ib feem ntawm pawg hydroxyl ntawm ester.

Tshuaj kho mob tso cai rau koj los tsim kev sib txuas ntxiv ntawm qhov chaw ntawm cov khoom siv polymer, uas pab ua kom muaj cua sov, ruaj khov.rau acids thiab shear force. Qhov tshwm sim, hloov cov hmoov txhuv nplej siab, yog siv los ua cov yas biodegradable. Nws decomposes ntawm 30 degrees hauv compost nyob rau hauv ob lub hlis, ua rau nws ib puag ncig zoo phooj ywg.

Txhawm rau txo tus nqi ntawm cov khoom siv, cov hmoov txhuv nplej siab yog siv, uas yog tov nrog talc thiab polyvinyl cawv. Nws tuaj yeem tsim tau siv cov khoom siv tib yam li cov yas zoo tib yam. Cov hmoov txhuv nplej siab hloov tau kuj tuaj yeem dyed thiab luam tawm siv cov txheej txheem ib txwm ua.

Thov nco ntsoov tias cov khoom siv no yog cov tshuaj tiv thaiv zoo li qub. Qhov tsis zoo ntawm cov hmoov txhuv nplej siab yog tias nws lub cev muaj zog feem ntau tsis zoo rau petrochemically tsim cov resins. Ntawd yog, polypropylene, nrog rau siab thiab tsis tshua muaj siab polyethylene. Thiab tseem, nws yog siv thiab muag ntawm lub khw. Yog li, nws yog siv los ua pallets rau cov khoom noj, cov yeeb yaj kiab ua liaj ua teb, cov ntaub ntawv ntim khoom, cov tais diav, nrog rau cov nets rau txiv hmab txiv ntoo thiab zaub.

Siv lwm yam ntuj tsim polymers

Nov yog lub ntsiab lus tshiab - biodegradable polymers. Kev tswj hwm qhov xwm txheej zoo ua rau muaj kev tshawb pom tshiab hauv cheeb tsam no. Yog li ntau lwm yam ntuj tsim polysaccharides yog siv los tsim cov yas biodegradable: chitin, chitosan, cellulose. Thiab tsis tsuas yog cais, tab sis kuj ua ke. Piv txwv li, ib zaj duab xis uas muaj zog ntxiv yog tau los ntawm chitosan, microcellulose fiber thiab gelatin. Thiab yog tias koj faus nws hauv av, ces nws yuav sai saitawg los ntawm microorganisms. Nws tuaj yeem siv rau ntim, tais thiab cov khoom zoo sib xws.

Ntxiv rau, kev sib txuas ntawm cellulose nrog dicarboxylic anhydrides thiab epoxy compounds yog qhov ntau heev. Lawv lub zog yog tias lawv decompose nyob rau hauv plaub lub lis piam. Lub raj mis, zaj duab xis rau mulching, pov tseg tableware yog tsim los ntawm cov khoom tshwm sim. Lawv cov creation thiab ntau lawm yog nquag loj hlob txhua txhua xyoo.

Biodegradability ntawm industrial polymers

Qhov teeb meem no muaj feem cuam tshuam. Biodegradable polymers, piv txwv uas tau hais los saum toj no rau kev cuam tshuam nrog ib puag ncig, yuav tsis kav ib xyoos hauv ib puag ncig. Txawm hais tias cov khoom lag luam tuaj yeem ua paug rau ntau xyoo thiab ntau pua xyoo. Tag nrho cov no siv rau polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyethylene terephthalate. Yog li ntawd, txo lub sij hawm ntawm lawv degradation yog ib txoj hauj lwm tseem ceeb.

Txhawm rau ua tiav qhov txiaj ntsig no, muaj ntau txoj hauv kev daws teeb meem. Ib txoj hauv kev zoo tshaj plaws yog kev qhia txog cov khoom siv tshwj xeeb rau hauv cov khoom siv polymer. Thiab nyob rau hauv tshav kub los yog nyob rau hauv lub teeb, cov txheej txheem ntawm lawv decomposition yog ceev. Qhov no yog tsim rau pov tseg tableware, fwj, ntim thiab ua liaj ua teb zaj duab xis, hnab. Tab sis, alas, kuj muaj teeb meem.

Thawj yog tias cov khoom ntxiv yuav tsum tau siv rau hauv txoj kev ib txwm - molding, casting, extrusion. Hauv qhov no, cov polymers yuav tsum tsis txhob decompose, txawm tias lawv raug kubua. Tsis tas li ntawd, cov additives yuav tsum tsis txhob ua kom lub decomposition ntawm polymers nyob rau hauv lub teeb, thiab tseem tso cai rau lub sij hawm ntev siv nyob rau hauv nws. Ntawd yog, nws yuav tsum tau ua kom paub tseeb tias cov txheej txheem degradation pib ntawm ib lub sijhawm. Nws nyuaj heev. Cov txheej txheem thev naus laus zis suav nrog qhov sib ntxiv ntawm 1-8% additives (piv txwv li, cov hmoov txhuv nplej siab yav dhau los tau qhia) ua ib feem ntawm cov txheej txheem me me, thaum cua sov ntawm cov khoom siv raw tsis pub tshaj 12 feeb. Tab sis nyob rau tib lub sijhawm, nws yog ib qho tsim nyog los xyuas kom meej tias lawv sib npaug sib npaug thoob plaws hauv cov khoom siv polymer. Tag nrho cov no ua rau nws ua tau kom lub sij hawm degradation nyob rau hauv thaj tsam ntawm cuaj lub hlis mus rau tsib xyoos.

Kev Pom Zoo rau kev txhim kho

Txawm hais tias kev siv biodegradable polymers tau txais lub zog, tam sim no lawv tsim ib feem measly ntawm tag nrho cov lag luam. Tab sis, txawm li cas los xij, lawv tseem pom ntau daim ntawv thov dav thiab tau dhau los ua neeg nyiam. Tam sim no lawv tau zoo heev nkag mus rau hauv lub niche ntawm ntim khoom noj. Tsis tas li ntawd, biodegradable polymers yog dav siv rau cov fwj pov tseg, khob, phaj, tais thiab tais. Lawv kuj tau tsim lawv tus kheej nyob rau hauv kev ua lag luam nyob rau hauv daim ntawv ntawm lub hnab rau kev sau thiab tom qab composting ntawm cov zaub mov pov tseg, hnab rau supermarkets, ua liaj ua teb films thiab tshuaj pleev ib ce. Nyob rau hauv rooj plaub no, cov cuab yeej txheem rau kev tsim cov biodegradable polymers tuaj yeem siv. Vim lawv qhov zoo (ua haujlwm rau kev degradation nyob rau hauv ib txwm muaj, tsis tshua muaj kev cuam tshuam rau dej vapor thiab oxygen, tsis muaj teeb meem nrog kev pov tseg, kev ywj pheej los ntawm petrochemical raw cov ntaub ntawv), lawv txuas ntxiv yeej.market.

Ntawm qhov tsis zoo, ib tus yuav tsum nco qab txog cov teeb meem ntawm kev tsim khoom loj thiab tus nqi siab. Qhov teeb meem no, rau qee qhov, tuaj yeem daws tau los ntawm cov txheej txheem ntau lawm. Kev txhim kho thev naus laus zis kuj tseem ua rau nws tuaj yeem tau txais cov khoom siv ruaj khov thiab hnav-resistant. Tsis tas li ntawd, nws yuav tsum raug sau tseg tias muaj lub siab nyiam tsom mus rau cov khoom lag luam nrog lub npe "eco". Qhov no yog txhawb nqa los ntawm ob qho tib si xov xwm thiab tsoomfwv thiab cov kev pabcuam thoob ntiaj teb.

Kev ntsuas kev txuag tau maj mam muab nruj, ua rau qee cov khoom siv yas raug txwv hauv qee lub tebchaws. Piv txwv li, pob khoom. Lawv raug txwv nyob rau hauv Bangladesh (tom qab lawv tau pom tias txhaws cov kab dej thiab ua rau dej nyab loj ob zaug) thiab Ltalis. Maj mam los ntawm kev ua tiav ntawm tus nqi tiag tiag uas yuav tsum tau them rau kev txiav txim siab tsis raug. Thiab kev nkag siab tias yuav tsum ua kom muaj kev nyab xeeb ntawm ib puag ncig yuav ua rau muaj kev txwv ntau dua rau cov khoom siv yas. Hmoov zoo, muaj kev thov rau kev hloov pauv mus rau qhov tseem kim dua, tab sis cov khoom siv ib puag ncig. Tsis tas li ntawd, cov chaw tshawb fawb hauv ntau lub tebchaws thiab cov tuam txhab ntiag tug loj tab tom nrhiav cov thev naus laus zis tshiab thiab pheej yig dua, uas yog xov xwm zoo.

Zaj lus

Yog li peb tau txiav txim siab dab tsi yog biodegradable polymers, cov txheej txheem ntawm kev tsim khoom thiab thaj tsam ntawm cov ntaub ntawv no. Muaj qhov tsis tu ncuakev txhim kho thiab txhim kho cov cuab yeej technology. Yog li cia peb cia siab tias nyob rau xyoo tom ntej, tus nqi ntawm biodegradable polymers tiag tiag yuav ntes nrog cov ntaub ntawv tau los ntawm cov txheej txheem ib txwm muaj. Tom qab ntawd, kev hloov pauv mus rau kev nyab xeeb thiab kev nyab xeeb dua ib puag ncig yuav tsuas yog lub sijhawm xwb.