Kubva payakatanga panguva uye mushure meHondo Yenyika II, indasitiri yekutengeserana yemapolymers-yakareba-chain-chain synthetic mamorekuru ayo "mapurasitiki" ari akajairika mazita-akakura nekukurumidza.Muna 2015, anopfuura 320 miriyoni matani emapolymers, kusasanganisa mafiber, akagadzirwa kutenderera pasirese.
[Chati: Kukurukurirana] Kusvika makore mashanu apfuura, vagadziri vezvigadzirwa zvepolymer havasati vafunga zvichaitika mushure mekupera kwehupenyu hwekutanga hwechigadzirwa chavo.Izvi zvave kutanga kuchinja, uye nyaya iyi inoda kuwedzera kutarisisa mumakore ari mberi.
THE PLASTICS INDUSTRY
"Purasitiki" yave imwe nzira isiriyo yekutsanangura mapolymer.Kazhinji inotorwa kubva mupetroleum kana gasi rechisikigo, aya mamorekuru ane cheni refu ane mazana kusvika kuzviuru zvezvinongedzo mucheni imwe neimwe.Cheni dzakareba dzinoburitsa zvinhu zvakakosha zvemuviri, senge simba uye kuomarara, izvo mamorekuru mapfupi haakwanise kuenderana.
"Plastiki" inonyatso kupfupikiswa kwe "thermoplastic," izwi rinotsanangura zvinhu zvepolymeric zvinogona kuumbwa uye kuumbwa zvakare uchishandisa kupisa.
Indasitiri yepolymer yemazuva ano yakagadzirwa zvakanaka naWallace Carothers kuDuPont muma1930s.Basa rake rinorwadza pamapoliamide rakatungamira mukutengeswa kwenaironi, sekuperevedza kwesiririka munguva yehondo kwakamanikidza vakadzi kuti vatarise kune imwe nzvimbo kuti vawane masokisi.
Zvimwe zvinhu pazvakashomeka mukati meHondo Yenyika II, vaongorori vakatarisa kune mapolymer ekugadzira kuti azadze mapeji.Semuenzaniso, kupihwa kwerabha yechisikigo yematayi emotokari kwakagurwa nekukunda kweJapan kweSoutheast Asia, zvichitungamira kune synthetic polymer yakaenzana.
Kuda kuziva kwakabudirira mukemistry kwakakonzera kuenderera mberi kwekugadzirwa kwemapolymers, kusanganisira iyo yava kushandiswa zvakanyanya polypropylene uye high-density polyethylene.Mamwe mapolymer, akadai seTeflon, akagumburwa netsaona.
Pakupedzisira, musanganiswa wezvinodiwa, kufambira mberi kwesainzi, uye runyararo zvakatungamira kune yakazara sutu yemapolymers ayo iwe aunogona kuziva zviri nyore se "plastiki."Aya mapolymer akakurumidza kutengeswa, nekuda kwechishuwo chekudzikisa huremu hwezvigadzirwa uye nekupa zvisingadhure dzimwe nzira kune zvakasikwa seselulosi kana donje.
MATYPES EPLASTIC
Kugadzirwa kwemapolymer ekugadzira pasi rose kunotongwa ne polyolefins-polyethylene uye polypropylene.
Polyethylene inouya mumhando mbiri: "high density" uye "low density."Pachiyero che molecular, high-density polyethylene inoratidzika semuzinga une mazino mapfupi nguva dzose.Iyo yakaderera-density vhezheni, kune rumwe rutivi, inoita senge muzinga une mazino asina kuganhurwa akaenzana ehurefu hwakangoerekana hwavapo-zvakaita serwizi nepanoyerera kana ukaonekwa kubva kumusoro.Kunyangwe ese ari maviri polyethylene, misiyano yechimiro inoita kuti zvinhu izvi zvibate zvakasiyana kana zvaumbwa kuita mafirimu kana zvimwe zvigadzirwa.
[Chati: Hurukuro]
Polyolefins inotonga nekuda kwezvikonzero zvishoma.Kutanga, anogona kugadzirwa pachishandiswa gasi rechisikigo risingadhure.Chechipiri, ndiwo akareruka ekugadzira mapolima anogadzirwa pamwero mukuru;density yavo yakadzikira zvekuti vanoyangarara.Chechitatu, mapololefin anodzivirira kukuvadzwa nemvura, mhepo, girisi, kuchenesa zvinonyungudutsa—zvinhu zvose zvingasangana nemapolima aya kana zvichishandiswa.Chekupedzisira, ari nyore kuumba kuita zvigadzirwa, nepo akasimba zvakakwana zvekuti kurongedza kwakagadzirwa kubva kwavari hakuzokanganisa murori yekutakurisa yakagara muzuva zuva rese.
Zvisinei, zvinhu izvi zvine zvakaipa zvakakomba.Vanodzikisira zvinorwadza zvishoma nezvishoma, zvichireva kuti polyolefins ichararama munzvimbo yemakumi emakore kusvika kumazana emakore.Zvichakadaro, masaisai nemhepo zvinozvikwenya, zvogadzira tunhu tuduku tunogona kudyiwa nehove nemhuka, zvichiita kuti tikwire necheni yezvokudya takananga kwatiri.
Kudzokorodza polyolefins hakuna kutwasanuka sezvaungade munhu nekuda kwekuunganidza nekuchenesa nyaya.Oxygen uye kupisa zvinokonzeresa kukuvadzwa kwecheni panguva yekudzokorora, asi chikafu nezvimwe zvinhu zvinosvibisa polyolefin.Kuenderera mberi kwekemistry kwakagadzira mamakisi matsva emapololefin ane simba rakawedzerwa uye kusimba, asi izvi hazvigone kugara zvichisangana nemamwe mamakisi panguva yekudzokorodza.Zvakare, ma polyolefins anowanzo kusanganiswa nezvimwe zvinhu mu multilayer kurongedza.Nepo aya akawanda ekuvaka anovaka anoshanda nemazvo, haagone kudzokorodza.
Mapolymers dzimwe nguva anoshoropodzwa nekugadzirwa kubva pakuwedzera kushomeka peturu uye gasi rechisikigo.Zvisinei, chikamu chegasi rechisikigo kana peturu inoshandiswa kugadzira mapolymer chakaderera zvikuru;isingasviki 5% yemafuta kana gasi rechisikigo rinogadzirwa gore rega rega rinoshandiswa kugadzira mapurasitiki.Uyezve, ethylene inogona kugadzirwa kubva munzimbe ethanol, sezvinoitwa zvokutengeserana neBraskem muBrazil.
MASHANDISIRO EPLASTIC
Zvichienderana nedunhu, kurongedza kunotora 35% kusvika 45% yepolymer yakagadzirwa yakazara, uko ma polyolefins anotonga.Polyethylene terephthalate, polyester, inotonga musika wemabhodhoro ezvinwiwa uye machira eshinda.
Kuvaka uye kuvaka kunodya imwe 20% yemapolymers akazara anogadzirwa, uko PVC pombi nemakemikari ayo makunakuna anotonga.Mapombi ePVC akareruka, anogona kunamwa pane kutengeswa kana kusungirirwa, uye anopikisa zvakanyanya kukuvadza kwechlorine mumvura.Nehurombo, maatomu eklorini anopa PVC mukana uyu anoita kuti zviome kudzokorodza- mazhinji anoraswa pakupera kwehupenyu.
Polyurethanes, mhuri yese yemapolymer ane hukama, anoshandiswa zvakanyanya mukuputika kwefuro kudzimba nemidziyo, pamwe chete mumachira ekuvaka.
Chikamu chemotokari chinoshandisa kuwedzera huwandu hwe thermoplastics, kunyanya kudzikisa huremu uye nekudaro kuwana hukuru hwemafuta ehuremu.European Union inofungidzira kuti 16% yehuremu hweavhareji yemotokari zvikamu zvepurasitiki, kunyanya zvemukati nezvikamu.
Anopfuura mamirioni makumi manomwe ematani e thermoplastics pagore anoshandiswa mumachira, kunyanya zvipfeko uye kapeti.Inopfuura 90% yemafuta ekugadzira, kunyanya polyethylene terephthalate, inogadzirwa muAsia.Kukura kwekushandiswa kwefayibha muzvipfeko kwauya nekurasikirwa kweshinda dzechisikigo sedonje nemvere dzemakwai, izvo zvinoda huwandu hwakakura hweminda yekurima kuti igadzirwe.Iyo synthetic fiber indasitiri yakaona kukura kunoshamisa kwezvipfeko uye kapeti, nekuda kwekufarira kwezvinhu zvakakosha senge kutambanudza, kunyorova, uye kufema.
Sezvekurongedza, machira haawanzo shandiswazve.Avhareji mugari wemuUS anogadzira anopfuura 90 mapaundi emarara emarara gore rega rega.Sekureva kweGreenpeace, munhu avhareji muna 2016 akatenga 60% zvimwe zvinhu zvembatya gore rega rega pane avhareji munhu makore gumi nemashanu apfuura, uye anochengeta zvipfeko kwenguva pfupi.
Nguva yekutumira: Jul-03-2023