Kana iwe uchida kuziva kuti chii chinonzi biodegradable plastics?, pamwe nekuziva nguva yehupenyu hwayo hunobatsira, kubva kune zvipi zvakasvibirira zvinogadzirwa, kubva rini zviri kugadzirwa uye kana zvichigona kushandiswazve, mibvunzo iyi ichapindurwa mune ino. chinyorwa chinonakidza, saka ndinokukoka kuti urambe uchiverenga.
Chii chinonzi Biodegradable Plastics?
Pamberi pefossil-based plastic yakashandiswa muma1930s, zvaingoitika bioplastic zvinhu zvaishandiswa. Panguva iyoyo, zvinhu zvakawanda zvepurasitiki zvaigadzirwa kubva kune biologically inotorwa mapolymer. Mumakore iwayo, chitubu chekugadzira bioplastics kana mapurasitiki ezvakasikwa rabha, cellulose, kugadzira Parkesin muma1850s, iyo gare gare, muna 1868, yakaunza celluloid plastiki zvinhu uye kunyange cellophane pakupera kwezana ramakore. XIX uye kutanga kweXX. Sezvimwewo zvimwe zvigadzirwa zvakatanga nezvikamu zvine casein, inova musanganiswa wemukaka wakagadzirwa nawo Galatita muna 1897.
Mumakore ekuma1940 ezana ramakore rechi1990, yekutanga tekinoroji bioplastic inozivikanwa nekuve neyakanyanya kunaka michina zvivakwa uye kugadzikana kwakanaka kwemakemikari kwakagadzirwa. Nekudaro, zvakabva kumaXNUMX zvichienda mberi uko kufambira mberi nekuwana izvo zvino zvinozivikanwa sebioplastics (PLA kana PHAs nemaplasticized starches) zvakaenderera, izvo zvinogadzirwa nekuda kwekufambira mberi mukutsvagisa kwegirinhi chemistry uye yechinyakare chemistry yekushandiswa kwebiomass, kureva. , kushandiswa kwe starch, shuga, cellulose nezvimwe.
Kubva pane zvakawanikwa izvi, sezvo tsvakiridzo ichifambira mberi, zvitsva zvakawanikwa zvemapolymers kubva kune zvipenyu kana biodegradable masosi akaitwa anogara achibuda, senge PEF, ayo anosiyana zvichienderana neakasiyana zviwanikwa zvinoongororwa uye kushandiswa kuunza kutsva kweBiodegradable Plastics, nechinangwa chekuwana kushandiswa kwakanakisisa kwemarara kubva kune zvakasiyana-siyana zvekushandisa kubva kune biological sources.
kutangazve mapurasitiki
Sezvo mitengo yemafuta yakadzikira, tsvakiridzo yakakwira kugadzira purasitiki kubva muoiri, kuwana purasitiki yakachipa yefossil yakabva, iyo yakabvumira kugadzirwa kwenhamba yakawanda yezvigadzirwa zvepurasitiki zvinogoneka uye zvinogara kwenguva refu. Izvi zvakakonzera kudzikira kwechido chekuenderera mberi nekugadzira Biodegradable Plastic. Nekudaro, sekusvibiswa kwenharaunda kunokonzerwa nekuraswa kwehuwandu hwezvigadzirwa zvepurasitiki zvefossil kwave kuzivikanwa, kufarira kugadzira zvigadzirwa neBiodegradable Plastic kwatanga zvakare.
Kufarira kutsva uku mukugadzira Biodegradable Plastic imhaka yekusvibiswa kunogadzirwa nepurasitiki yefossil kwakabva uye nekuwedzera kwemutengo wemafuta, pamwe nekudzikira kwakanyanya kwematura emafuta. Yakabatana nekufarira kwenharaunda dzesainzi nemaindasitiri kuita tsvakiridzo yekugadzira maBiodegradable Plastics kana EDPs (mapolymer nemapurasitiki anoshatisa nharaunda).
Kuchinja mapurasitiki ane fossil ari kushandiswa pakugadzira zvinhu zvakasiyana-siyana zveBiodegradable Plastic chiyero chinogona kubatsira zvakatipoteredza nekuderedza kusvibisa kunoitwa nemapurasitiki ane fossil. Izvi zvakakonzera kukurudzira kutsva mukutsvagisa kuwana mapurasitiki kubva kwakasiyana kwakabva kwakasikwa, uye polyhydroxyalkanoates isarudzo inogoneka. Kunyanya sezvo tsvina kubva kuBiodegradable Plastics inogona kurapwa senge iyo ye organic mavambo uye kuparara kwayo kunoitika munguva pfupi yenguva.
Kuwedzeredzwa
Dhizaini yekugadzirwa kweBiodegradable Plastic ine chinangwa chekuti nekuita kwezvipenyu zvipenyu vanogona kuigadzira kuti vawane kabhoni, kubva mukudya zvinhu zvepurasitiki. Kune mamwe mapurasitiki ari pamusika anogadzirwa ane organic kana biobased raw materials, ayo anogona kudzokororwa zvinhu zvakaita semabhanana kana mabhanana, cassava, cellulose, legumes inopa huwandu hukuru hwelactic acid, soya bean mafuta uye mbatatisi starch. Rudzi urwu rwepurasitiki kana vasvika kuhupenyu hwavo hunobatsira vari Biodegraded neaerobic microorganisms.
Biodegradable Plastics inocheneswa nebhakitiriya inoda kuvepo kweokisijeni kana aerobic, mumacomposts makuru, mamwe maindasitiri ane tembiricha yakanyanya uye oxygen yakakwana. Nekudaro, mamwe maBiodegradable kana biobased Plastics haagadzirike mukati menguva pfupi yenguva, izvi zvinokonzerwa nekuti mamwe matekinoroji akagadzirwa ekuti, kuve nemuriwo wakasara sechitubu, unokonzeresa polymer ine hunhu hwakafanana nepurasitiki. yefossil mavambo nechinangwa chekuchengetedza maitiro ayo emuchina uye kuderera zvishoma nezvishoma. Biodegradable Plastics, nekuti ine mashoma emagetsi zvivakwa, haigone kudzokororwa.
Zvizvarwa zvitsva zvekuwedzera zvakagadzirwa, izvo zvine anaerobic enzymatic tekinoroji inoburitsa biobased plastic painokandwa muduru kana tsvina ine tsvina uye nekuda kwekuwanda kuunganidzwa kwemarara uye kushoma kuvapo kweokisijeni, iyo anaerobic bhakitiriya inowanda, tanga nekukurumidza biodegradation yezvinhu izvi zvepurasitiki.
Izvi zvitsva zvinowedzera zvinobvumira plastiki kuti ishandiswe zvakare, sezvo isingakanganise maitiro ayo epakutanga uye, kusiyana nematekinoroji akadai sezviwedzere zvinosvibiswa ne oxidation, kupisa kwakanyanya kana kuratidzwa kwechiedza chakakwirira, icho, pasi pemamiriro ekunze, chinotanga kuparara. kushandura zvimiro zvavo, kugadzira mapurasitiki madiki uye kudzivirira kudzokorodza kwawo, izvi nekuti zvikamu zvebiodegradation zvinofamba nemubiological uye kwete nzira dzemuviri.
Yakagadzirwa ne starch
Chigadzirwa chikuru chekugadzira Biodegradable Plastics is starch, iyi polima yechisikigo yakavakirwa pachibage, gorosi kana mbatatisi. Pazvitubu zvitatu izvi zvinogadzirwa ne starch, yakanakisa ndiyo inogadzirwa kubva kune mbatatisi starch. Izvi zviri kukonzerwa nekuti kunze kwekuve chiwanikwa chinovandudzwa, nguva yekugadzirwa kwayo ipfupi uye ine goho guru pahekita imwe chete inogadzirwa, inoshandisa mvura shoma uye inopa pundutso yakanaka muchikamu chekurima kuburikidza nekutorazve mawedzero eminda yakasiiwa.
Biodegradable Plastic inogadzirwa zvichibva pane starch inobviswa muchibage, ichishandurwa nema microorganisms kuita mamorekuru madiki elactic acid kubva panoitwa polymeric cheni dzepolylactic acid (PLA). Iyo PLA cheni yekuyambuka inovamba iyo biodegradable purasitiki pepa kubva kune akasiyana-siyana asina kusvibisa epurasitiki zvigadzirwa zvinogona kugadzirwa.
Aya maBiodegradable Plastics anokonzerwa nekugadziriswa kwe starch, anogona kubaiwa, kuvakwa uye kugadzirwa ne thermoform kana anogona kuumbwa kuti awedzere tembiricha, zvakafanana nezvinoitika nemapurasitiki echinyakare anogadzirwa kubva mupetroleum uye saizvozvi, izvo zvinoguma zvigadzirwa zvine zvakafanana zvemuviri-kemikari.
Izvo zvivakwa
Ukama huri pakati pe starch nemvura chibereko chekuvapo kwenhamba yakawanda yemapoka e-hydroxyl anodzivirira kunwa kwemvura uye ane simba rakaipa pamusoro peBiodegradable Plastic products. Mamiriro ezvinhu aya aita kuti kuferefetwa kwakasiyana-siyana mukushandurwa kwe starch yechisikigo kuburikidza nekuita kwemakemikari kunoshandura mapoka ehydroxyl uye kudyidzana nemamwe mashoma mapolymers ehydrophilic kana kushandura zvigadzirwa nenzira dzemuviri kuburikidza nekuvharira nzira dzakadai semachira epamusoro. Uku kudzikiswa kwe hydrophilicity kunodzikisa mutengo.
Mhando yeBiodegradable Plastics
Nekuwedzera, maindasitiri ari kushandisa midziyo inogadzirwa neBiodegradable Plastics senzira yekubatsira kudzikisira kusvibiswa kwezvakatipoteredza. Saizvozvo, serutsigiro kuongororo dzese dzinoitwa kuwedzera kugadzirwa kweBiodegradable Plastics izvo zvinozotungamira kune zvakanaka kugadzirwa kwekurima pasina kuderera kwezvakatipoteredza. Iwo mapurasitiki anogadzirwa biodegradable mapurasitiki anoiswa sezvizvi:
Mapolymers anobviswa zvakananga kubva kubiomass
Iyi mhando yepolymer iri muchikamu chekudzidza uye inotarisirwa kugadzira mapepa anodyiwa uye akaturikidzana, ane chinangwa chekuchengetedza chikafu. Nekuda kweizvi, mapolysaccharides akasiyana uye hydrocolloids yeprotein mavambo anodzidzwa, senge cassava starch yakagadziriswa neglycerol, polyethylene glycol, yakajairwa uye pre-gelatinized corn starch, carboxymethylcellulose, pectin yakasanganiswa nesodium alginate, pectin, gum tragacanth, gum guar, ethylcellulose, gelatin yakawedzerwa ne glycerol, gelatin-casein cross-yakabatanidzwa ne transglutaminase, sorbitol uye sucrose, casein, whey, soy uye gorosi gluten.
Nekuti gorosi gluten rinoshandiswa mune aya mapolymers akabviswa kubva mubiomass, ine muchetura kune avo allergic kune gluten uye vanotambura nechirwere checeliac, icho chinokanganisa 15% yehuwandu hwepasirese uye iri kuwedzera. Kushandiswa kweguten mumhando iyi yeBiodegradable Plastics kunotungamirira kuhutano husina kunaka hwehutano hwevanhu, nekuda kweizvi, chikonzero chekutsvaga mhinduro uye kugadzirisa kushandiswa kana kwete kwe gluten mukugadzirwa kwemhando iyi yepurasitiki.
Polymers kubva kukirasi yemakemikari synthesis
Iri rudzi rwemapolymers anogadzirwa nekirasi yemakemikari synthesis anoshandisa biological monomers kubva kunowanikwazve masosi. Monomers ishoma mamorekuru huremu makomisheni ayo akasanganiswa nekuita kwemakemikari pakati pawo, ayo anogona kugadzira morekuru ane huremu hukuru, hunodaidzwa kuti mapolymer kana hombe uye matatu-dimensional molecule.
polymers kubva kune tupukanana
Izvi zvinogadzirwa semugumisiro wekuvirisa maitiro, izvo, zvichienderana nekwakabva kabhoni inoshandiswa, inoshandisa nzira dzakasiyana-siyana dzebiosynthetic. Aya mapolymer anogadzirwa neakasiyana ma microorganisms uye huwandu hwevagadziri huri kuwedzera uye imwe sosi inoshanduka zvirimwa. Biodegradable Plastics anobva kubhakitiriya akaiswa muboka iri, uko polyhydroxyalkanoates (PHA) uye polylactic acid (PLA) inowanikwa. polyhydroxyalkanoates (PHA) nekuti anotorwa kubva kune zvinogonekazve uye nekuda kwekugona kusvibisa biodegrade, anonzi "double green polymers".
Polylactic asidhi (PLA)
Munguva yephotosynthesis yezvirimwa, macarbohydrates anogadzirwa kuti abudise shuga uye starch (natural polymer), nechinangwa chekuchengetedza simba. Kunobva kunobva polylactic asidhi kubva chibage uye zviyo zvegorosi zvine huwandu hwakawanda hwestarch muzviyo zvadzo. Iyo Biodegradable Plastics mavanogadzirwa kubva mupolymer iyi vane midziyo yekuve neresin inogona kubaiwa, inoumbwa neextrusion uye thermoformed.
Rudzi urwu rwepolymer ndeimwe yeBiodegradable Plastics iri kudzidzwa zvakanyanya uye yave kuwanikwa pamusika kubva kuma1990s. Kugadzirwa kwayo kunobva mukubvisa starch kubva muchibage chirimwa, icho chinoshandurwa kuita diki molecule nema microorganisms, lactic acid kana iyo 2-hydroxypropionic monomer, iyo inoumba cheni dzine mamorekuru maumbirwo akafanana nemapurasitiki ekwakabva fossil. PLA imhando yeBiodegradable Plastic inoshandiswa kugadzira midziyo yechikafu nemabhodhoro epurasitiki ezvinwiwa zvinotonhora.
Polyhydroxyalkanoate (PHAs)
Iyi mhando yeBiodegradable Plastics inonzi Polyhydroxyalkanoate (PHAs), inogadzirwa zvakanyanya neGram negative bacteria, uye ishoma neGram positive bacteria. Iyo PHA yakawanikwa kekutanga yaive PHB, mugore ra1925 paPasteur Institute, Lemoigne paaidzidza Bacillus megaterium uye akacherechedza kugadzirwa kwePHB. Muna 1958, masayendisiti Macrae naWildinson vakasarudza izvozvo Bacillus megaterium yakachengeta iyo polymer kana hukama pakati peglucose nenitrogen husina kuenzana uye kudzikira kwayo kana kabhoni kana sosi resimba rakundikana. Anosvika zana nemakumi mashanu akasiyana epolyhydroxyalkanoates anozivikanwa parizvino.
Chigadzirwa chekutanga kubva mupolymer iyi chaizivikanwa se "Biopol" kwacho chinobva kuRalstonia eutropha, kubva kuglucose uye propionic acid. Parizvino, Biopol inogadzirwa kubva kabhoni kubva kubhakitiriya rimwechete, ine yakakwirira biodegradable kugona uye zviri nani thermomechanical zvivakwa pane yakachena PHB.
Polyhydroxyalkanoate (PHAs) inoora, isiri-chepfu uye inowirirana nenharaunda. Kugadzirwa kweBiodegradable Plastic kunotungamira mukudzikira kwekutsamira pakugadzira mapurasitiki sechinhu chinobva muindasitiri yemafuta, nekudaro kudzikiswa kwemarara akasimba uye magasi anokonzera greenhouse effect.
Biodegradable Plastics uye Indasitiri
Zvinoenderana nedata rakataurwa neInternational Association uye Working Boka reBiodegradable Polymers (IBAW), kwainogadzirwa Biodegradable Plastics yakanangana nezvikamu zvekuchengetera, zvemishonga, zvekurima nezvimwe zvinoraswa. Anoshandiswawo mukugadzira nharembozha, makomputa, midziyo yemavhidhiyo nezvimwe. Zvinofanira kucherechedzwa kuti maererano negumi muzana yepurasitiki inoshandiswa mukugadzira zvigadzirwa muindasitiri yemagetsi ine Biodegradable Plastics.
Fossil-Yakavakirwa Plastiki uye Zvakatipoteredza
Sezvo plastiki yakatanga kushandiswa kugadzira zvinhu, iyi indasitiri yave chiitiko. Zvichikonzera kugadzirwa kwezvinhu zvakasiyana-siyana izvo munguva yakapfuura zvakanga zvisingakoshi muupenyu hwezuva nezuva hwevanhu. Izvi zvinogadzirwa kuti zvipindure kune indasitiri yakakura yakagadzira zvinhu zvine mashandisirwo akasiyana siyana uye nekuda kwevanoongorora zvakatipoteredza vauya kuzoshandisa zita rekuti "Plastic Civilization", tichitarisa kukosha kwechinhu ichi mukusimudzira nekuvandudzwa kwehupenyu hwehupenyu. yenzanga munzvimbo yesainzi uye tekinoroji.
Zvinenge zvese zvigadzirwa zvakaputirwa kana kugadzirwa nepurasitiki, inobvisa girazi, mapepa nemakadhibhokisi wrappers uye midziyo. Purasitiki inoshandiswa semapepa echikafu, mishonga, michina, zvemagetsi, uye mamwe marudzi ezvigadzirwa zvinoraswa pasina kukosha kupi kana zvasvika paupenyu hwazvo hunobatsira kana kuti chimwe chitsva chatengwa. Izvi zvakakonzera mavambo emarara makuru emugungwa, ayo anoipa zita re "plastic soup", achigadzira nzvimbo huru yekurasira pasi.
Uku kuwanda kwakakwirira kwemarara epurasitiki kwakagadzira dambudziko guru rekusvibiswa kwezvakatipoteredza, nemapurasitiki akakwirira uye akaderera. Hunhu hwepurasitiki kubva kupetroleum hunofarira kuramba kwayo kukuru kushatiswa nemamiriro ekunze uye zvakatonyanya nekuti haina biodegradable. Chete mwaranzi ye UV solar rays inogona kukonzera kuderera kwepakati-kati mupurasitiki, zvishoma nezvishoma ichiparadza iyo polymeric zvisungo uye nekuishandura kuita chinotyoka uye chisina kusimba chigadzirwa.
Kuunganidzwa kwepamusoro kwemapurasitiki akakandwa munharaunda kunokanganisa miviri yemvura nekukweverwa kubva munzizi uye kutamiswa kusvikira yayerera mugungwa; inosvibisa mvura nezvigadzirwa zvavaive nazvo; vanokonzera zvirwere zvakadai sedengue, nemhaka yokumira kwemvura yakasviba uye mumagaba epurasitiki ari nzvimbo dzokuberekera umhutu. Inobata zviitwa zvekuvaraidza uye kushanya, nekukanganisa nzvimbo yechisikigo nenzvimbo dzakaita semapaki, nzira, migwagwa, zvivakwa uye zvivakwa.
Zvinokonzera kufa kwemhuka neshiri kungave nekudyiwa kweaya mapurasitiki akashatiswa kana nekudzipwa, semhuka dzinoisa misoro yadzo mumabhegi uye dzisingakwanise kuiburitsa gare gare. Saizvozvowo, shiri dzinoturikwa nemhete dzepurasitiki kana mapadza kubva mumabhegi epurasitiki. Somuenzaniso, muna 1967, munharaunda yeLa Serena muChile, kufa kwechiverengero chakati chembudzi munguva yokusanaya kwemvura kwenguva refu iyo yakadya zvisaririra zvemasaga e<em>polyethylene akakandwa kumahombekombe navanhu, uye pakupedza mombe, dzakafa. .mumaawa mashoma ekuzvipedza.
Zvigaba zvepurasitiki zvefossil zvakabva zvave kusagadzikana kukuru mumaguta. Nekuti mabatirwo emarara aya anodhura zvakanyanya kuvakuru vekanzuru vanotungamira marara akasimba nekuda kwehuwandu hwemidziyo uye huwandu hwayo. Plastiki inokonzera matambudziko panguva yekuunganidza kwayo uye kuraswa kwekupedzisira. Izvi zvinodaro nekuti kuunganidzwa kwemarara, rori inotakura marara inokwanisa kutakura matani angangosvika gumi nemaviri emarara akajairika, inotakura chete matani mashanu kana matanhatu epurasitiki yakamanikana uye matani maviri chete epurasitiki isina kuumbwa.
Ipurasitiki inonyanya kuwanikwa mumarara akaunganidzwa, kupfuura chero chinhu, PET midziyo yepurasitiki kubva mumabhodhoro anoraswa emvura yekunwa, mafuta, zvinwiwa zvinyoro, majusi uye zvimwe zvekudya. Izvi zvinodaro nekuti makambani akamira kushandisa mabhodhoro egirazi kana midziyo uye akaashandura kune anodzoserwa uye asingadzoke epurasitiki midziyo, zvichikonzera dambudziko rekusvibiswa kwezvakatipoteredza.
Kuchengetedzwa Kwezvakatipoteredza
Kugadzirwa kweBiodegradable Plastic kwakazadzikiswa nechinangwa chekuti chinhu ichi chakaitwa biodegraded munguva shoma nekuita kwema microorganisms uye nekudaro kunyangarika zvachose. Ichi chinangwa chakaitwa muzvigadzirwa zvakagadzirwa nenylon: mabhakitiriya maviri anodya nylon, flavobacteria uye Pseudomonas, anopindira mukuora kwavo. Masayendisiti anofunga dzidziso yekuti mune ramangwana mamwe ma microorganisms anoshandura nzira dzawo dzemetabolism uye kushandisa plastiki se substrate.
Iko kusvibiswa kwemazuva ano kunokonzerwa nehuwandu hwepurasitiki yefossil yakabva kunokonzerwa nekuti rudzi urwu rwepurasitiki runoumbwa nezvivako zvisingagadziriswi nekuora, zvichiita kuti pave nekukanganisa hupenyu hwehupenyu hwehupenyu. Semhinduro kudambudziko iri rekusvibiswa kwezvakatipoteredza, maindasitiri akatungamira zviito zvawo pakuvandudza uye kushandiswa kwezvinhu zvakareruka zvinodzikisira zvakasikwa, zvine basa rakasiyana-siyana uye mutengo wakaderera wekudyara.
Iyi Biodegradable Plastic inodzokororwa zvakare sezvo iri chikamu chezve nzira yekuwanazve makomisheni eaya mapurasitiki ayo mukugadzirira kwawo akashandiswa echisikigo makomisheni kuitira kuti ashandiswezve, pasi pemamiriro ekuchengetedzwa kwemaindasitiri nehutsanana, zvinhu zvine hunhu hwavanogadzira. antioxidants, inogoneka, inodzivirira, isina mvura uye inochinjika, pakati pevamwe.
Kana iwe uchida kuziva zvakawanda nezve misoro ine chekuita nehunhu hunoshamisa uye maitiro ekuzvichengeta, ini ndinokukoka iwe kuti uverenge zvinotevera zvinyorwa: