(I-PVC) i-thermoplastic edumile engenaphunga, eqinile, ephukayo, futhi ngokuvamile emhlophe ngombala.Njengamanje ibalwa njengepulasitiki yesithathu esetshenziswa kakhulu emhlabeni (ngemuva kwe-polyethylene ne-polypropylene).I-PVC isetshenziswa kakhulu ekufakweni kwamapayipi nokukhipha amanzi, nakuba ibuye ithengiswe ngendlela yama-pellets noma njenge-resin kwifomu yayo yempushana.
Ukusetshenziswa kwe-PVC
Ukusetshenziswa kwe-PVC kuhamba phambili embonini yokwakha izindlu.Isetshenziswa njalo njengokumiselela noma okunye okuhlukile kwamapayipi ensimbi (ikakhulukazi ithusi, insimbi, noma insimbi ecijile), nasezinhlelweni eziningi lapho ukugqwala kungonakalisa ukusebenza futhi kwenyuse izindleko zokulungisa.Ngaphezu kwezicelo zokuhlala, i-PVC iphinde isetshenziselwe amaphrojekthi kamasipala, izimboni, ezempi, nezohwebo.
Ngokuvamile, i-PVC kulula kakhulu ukusebenza nayo kunepayipi lensimbi.Inganqunywa ubude obufunayo ngamathuluzi alula wezandla.Izinto ezifakwayo namapayipi amapayipi akudingeki ukuthi zishiselwe.Amapayipi axhumene nokusetshenziswa kwamalunga, usimende oncibilikayo, nezinsimbi ezikhethekile.Enye inzuzo ye-PVC ukuthi eminye imikhiqizo okufakwe kuyo ama-plasticizers ithambile futhi iguquguqukayo, ngokuphambene nokuqina, okwenza kube lula ukuyifaka.I-PVC iphinde isetshenziswe kabanzi kuwo womabili amafomu aguquguqukayo futhi aqinile njenge-insulation yezingxenye zikagesi ezifana nocingo nekhebula.
Embonini yezokunakekelwa kwempilo, i-PVC ingatholakala ngendlela yamashubhu okuphakelayo, izikhwama zegazi, izikhwama ze-intravenous (IV), izingxenye zemishini ye-dialysis, kanye nenqwaba yezinye izinto.Kufanele kuqashelwe ukuthi izicelo ezinjalo zingenzeka kuphela lapho ama-phthalates—amakhemikhali akhiqiza amamaki aguquguqukayo e-PVC namanye amapulasitiki—engezwa ekwakhiweni kwe-PVC.
Imikhiqizo evamile yabathengi njengamajazi emvula, izikhwama zepulasitiki, amathoyizi ezingane, amakhadi esikweletu, amapayipi angadini, amafreyimu eminyango namafasitela, namakhethini eshawa—ukubala nje izinto ezimbalwa ongazithola endlini yakho siqu—nazo zenziwe nge-PVC ifomu elilodwa noma elinye.
I-PVC yenziwe kanjani
Nakuba amapulasitiki ayinto eyenziwe ngabantu, izithako ezimbili eziyinhloko ezingena ku-PVC-usawoti namafutha-ziyizinto eziphilayo.Ukuze wenze i-PVC, into yokuqala okufanele uyenze ukuhlukanisa i-ethylene, i-gas derivative yemvelo, kulokho okwaziwa ngokuthi "i-feedstock."Embonini yamakhemikhali, i-petroleum iyisitoko esikhethwayo samakhemikhali amaningi, okuhlanganisa i-methane, i-propylene, ne-butane.(Isitokwe semvelo sokuphakelayo sihlanganisa ulwelwe, okuwukudla okuvamile kwamafutha e-hydrocarbon, kanye nommbila nomoba, kokubili okungenye yezindlela zokudla ze-ethanol.)
Ukuze kuhlukaniswe i-ethanol, uphethiloli owuketshezi ushiswa esithandweni somusi futhi ufakwe ngaphansi kwengcindezi enkulu (inqubo ebizwa ngokuthi i-thermal cracking) ukuze kulethwe izinguquko esisindweni samangqamuzana amakhemikhali esitokisini sokudla.Ngokushintsha isisindo sayo samangqamuzana, i-ethylene ingabonakala, ihlukaniswe, futhi ivunwe.Uma lokho sekwenziwe, ipholiswa ibe yisimo sayo samanzi.
Ingxenye elandelayo yenqubo ihilela ukukhipha ingxenye ye-chlorine kusawoti emanzini olwandle.Ngokudlula amandla kagesi anamandla ngokusebenzisa isixazululo samanzi anosawoti (i-electrolysis), i-electron eyengeziwe yengezwa kuma-molecule e-chlorine, futhi, ivumela ukuba ibonakale, ihlukaniswe, futhi ikhishwe.
Manje usunezingxenye eziyinhloko.
Lapho i-ethylene ne-chlorine kuhlangana, ukusabela kwamakhemikhali ezikukhiqizayo kudala i-ethylene dichloride (EDC).I-EDC ibhekana nenqubo yesibili yokuqhekeka okushisayo, yona, ikhiqiza i-vinyl chloride monomer (VCM).Okulandelayo, i-VCM idluliswa nge-reactor equkethe i-catalyst, eyenza ama-molecule e-VCM axhumane (i-polymerization).Lapho ama-molecule e-VCM exhuma, uthola i-PVC resin-isisekelo sazo zonke izinhlanganisela ze-vinyl.
Izinhlanganisela ze-vinyl ngokwezifiso eziqinile, eziguquguqukayo, noma ezihlanganisiwe zidalwa ngokuxuba inhlaka nezinhlobo ezahlukene zepulasitiki, iziqinisi, nezishintshi ukuze kuzuzwe izakhiwo ezifiselekayo ezihlanganisa yonke into kusukela kumbala, ukuthungwa, nokuvumelana nezimo kuya ekuqineni esimweni sezulu esibi kakhulu nezimo ze-UV.
Izinzuzo ze-PVC
I-PVC iwumsebenzi obiza kancane ongasindi, othambile, futhi ovamise ukuphatheka kalula nokuwufaka.Uma kuqhathaniswa nezinye izinhlobo zama-polymers, inqubo yayo yokukhiqiza ayikhawulelwe ekusebenziseni uwoyela ongahluziwe noma igesi yemvelo.(Abanye baphikisa ngokuthi lokhu kwenza i-PVC ibe "ipulasitiki esimeme" njengoba ingancikile ezinhlotsheni zamandla ezingavuseleleki.)
I-PVC futhi iqinile futhi ayithinteki ukugqwala noma ezinye izinhlobo zokuwohloka, futhi ngenxa yalokho, ingagcinwa isikhathi eside.Ukwakhiwa kwayo kungaguqulelwa kalula kube amafomu ahlukene ukuze isetshenziswe ezimbonini ezihlukahlukene nezinhlelo zokusebenza, okuhlanganisa okuqinisekile.I-PVC iphinde ibe nokusimama kwamakhemikhali, okuyisici esibalulekile lapho imikhiqizo ye-PVC isetshenziswa ezindaweni ezinezinhlobo ezahlukene zamakhemikhali.Lesi sici siqinisekisa ukuthi i-PVC igcina izakhiwo zayo ngaphandle kokwenza izinguquko eziphawulekayo lapho amakhemikhali ethulwa.Ezinye izinzuzo zifaka:
● I-Biocompatibility
● Ukucaca nokungafihli lutho
● Ukumelana nokuqhekeka kwengcindezi yamakhemikhali
● I-conductivity ephansi ye-thermal
● Idinga ukunakekelwa okuncane noma ukunganakwa
Njenge-thermoplastic, i-PVC ingagaywa kabusha futhi iguqulwe ibe yimikhiqizo emisha yezimboni ezahlukene, nakuba ngenxa yokwakheka okuningi okuhlukene okusetshenziselwa ukwakhiwa kwe-PVC, akuyona inqubo elula ngaso sonke isikhathi.
Ukungalungi kwe-PVC
I-PVC ingaba ne-chlorine efika ku-57%.Ikhabhoni—etholakala emikhiqizweni ka-petroleum—nayo ngokuvamile isetshenziswa lapho kukhiqizwa.Ngenxa yobuthi obungase bukhishwe ngesikhathi sokukhiqizwa, lapho buchayeka emlilweni, noma njengoba bubola ezindaweni zokulahla imfucumfucu, i-PVC iye yabizwa ngabacwaningi bezokwelapha kanye nezazi zemvelo ngokuthi "ipulasitiki enobuthi."
Ukukhathazeka kwezempilo okuhlobene ne-PVC kusazofakazelwa ngokwezibalo, nokho, lobu buthi buye baxhunyaniswa nezimo ezihlanganisa kodwa ezingagcini nje ngomdlavuza, ukukhubazeka komntwana, ukuphazamiseka kwe-endocrine, isifuba somoya, nokuncipha kokusebenza kwamaphaphu.Nakuba abakhiqizi bekhomba usawoti omningi we-PVC njengento engokwemvelo futhi engenabungozi, isayensi iphakamisa ukuthi i-sodium-kanye nokukhululwa kwe-dioxin ne-phthalate-empeleni kuyizici ezingaba nomthelela ezingozini zemvelo nempilo ye-PVC.
Ikusasa lePVC Plastiki
Ukukhathazeka mayelana nezingozi ezihlobene ne-PVC futhi kuye kwabangela ucwaningo ekusetshenzisweni kwe-ethanol yomoba ukuze kutholakale ukudla esikhundleni se-naphtha (uwoyela ovuthayo otholwe ukucwiliswa kwe-distillation okomile kwamalahle, i-shale, noma i-petroleum).Ucwaningo olwengeziwe luyenziwa kuma-plasticizers asekelwe ku-bio ngenhloso yokudala ezinye izindlela ezingenayo i-phthalate.Nakuba lezi zivivinyo zisezigabeni zakho zokuqala, ithemba ukuthuthukisa izinhlobo ezizinzile ze-PVC ukunciphisa umthelela omubi ongaba khona empilweni yomuntu kanye nemvelo ngesikhathi sokukhiqiza, ukusetshenziswa, kanye nezigaba zokulahla.
Isikhathi sokuthumela: Apr-07-2022