Ukuthuthukiswa kanye nokusetshenziswa kwamapulasitiki e-polymer abolayo, amapulasitiki abolayo wuhlobo olusha olunomsebenzi wokucekelwa phansi kwezinto ze-polymer, lapho kusetshenziswa, kuhlobene nohlobo olufanayo lwepulasitiki evamile nempilo ehambisanayo nokusebenza kwesicelo esifanele, futhi ngemva kokusebenza kwayo okuphelele, izinto ezisetshenziswayo zingonakaliswa ngokushesha ezimweni zemvelo zibe lula ukunikezwa izingcezu zemvelo noma ukuchotshozwa, futhi ngokuhamba kwesikhathi ukuwohloka okwengeziwe kube yimikhiqizo ye-oxidation (CO2 namanzi), ibuyele emvelweni.
Ukuthuthukiswa kanye nokusetshenziswa kwe-biodegradableamapulasitiki e-polymer, amapulasitiki abolayo uhlobo olusha olunomsebenzi wokucekelwa phansi kwezinto ze-polymer, inqubo yokusetshenziswa, ihlobene nohlobo olufanayo lwepulasitiki evamile nempilo ehambisanayo nokusebenza kwesicelo esifanele, futhi ngemva komsebenzi wayo ophelele, impahla. zingonakaliswa ngokushesha endaweni yemvelo izimo ziba lula ukuthi zinikezwe izingcezwana zemvelo noma zichotshozwe, futhi ngokuhamba kwesikhathi ukuwohloka okwengeziwe kube yimikhiqizo ye-oxidation (CO2 namanzi), ibuyele emvelweni.
Ngokusekelwe ekungcolisweni kwemvelo okubangelwa udoti wepulasitiki, kanye nesidingo sokuvikelwa kwemvelo kanye nezidingo zabantu, kuyaphuthuma ukutadisha izinto ze-polymer ezonakele.Esikhathini esithile nangaphansi kwezimo ezithile zemvelo, ukwakheka kwamakhemikhali kwamapulasitiki abolayo azoshintsha.Ngokwezizathu zezinguquko ekwakhekeni kwamakhemikhali awo, amapulasitiki angaboli angahlukaniswa abe izigaba ezimbili: amapulasitiki abolayo kanye namapulasitiki abolayo.
1. Indlela yokuwohloka kwamapulasitiki awonakele
Ngokuvamile, ipulasitiki eyonakaliswayo ibhekisela ohlotsheni lwepulasitiki olungaboliswa lube ama-molecule amancane ngokusebenza kwama-microorganisms enhlabathini noma emisebeni yelanga.Kumelwe ihlangabezane nezidingo zokusetshenziswa kwemikhiqizo futhi kulula ukuyicubungula ngesisekelo izakhiwo ze-biodegradable.Imvelo yesenzo sokukhanya kwelanga ezintweni ze-polymer ingumphumela ophelele wokukhanya kwe-ultraviolet ekukhanyeni kwelanga nomoya-mpilo osemoyeni, ngakho kubizwa nangokuthi ukuwohloka kwe-photooxidation.Thatha i-polyolefin njengesibonelo ukuze uchaze indlela yokuwohloka kwe-photooxidation.Empeleni, i-photooxidation ibangela ukwephulwa kweketango noma ukuphambana kwama-polymers, futhi amanye amaqembu asebenzayo aqukethe umoya-mpilo, njengama-carboxylic acid, ama-peroxides, ama-ketone nama-alcohol, akhiwa kule nqubo.Izinsalela ze-Catalyst kuma-polymers kanye nokuqaliswa kwe-peroxide namaqembu e-carboxyl ezethulwa ngesikhathi sokucubungula ziyimithombo eyinhloko yokuwohloka.
Ngaphansi kokusebenza kwama-microorganisms (ikakhulukazi isikhunta, amabhaktheriya noma ulwelwe, njll.), ama-polymers angaguguleka noma agaywe i-metabolism ukuze abangele izinguquko ekwakhekeni kwawo kwamakhemikhali kanye nokuncipha kwesisindo samangqamuzana.Indlela yokwenza ingahlukaniswa ngokuyinhloko ngezimo ezimbili:
(1) isenzo se-biophysical.Okusho ukuthi, emva kokuguguleka kwemikhiqizo yepulasitiki ngama-microorganisms, ukukhula kwamangqamuzana e-biological, kukhuthaze ukubola kwama-polymers, i-ionization noma i-proton, lesi senzo somzimba ku-polymer sibangele ukulimala komshini, isisindo esiphezulu se-polymer sibe yizicucu ze-oligomer, ukuze ukufeza inhloso yokuwohloka komzimba.
(2) isenzo se-biochemical - isenzo esiqondile sama-enzyme.Lesi simo sibangelwa ukuguguleka kwama-enzyme akhiqizwe isikhunta noma amagciwane, okuholela ekuqhekekeni noma ekuhlakazweni kwe-oxidative kwamapulasitiki, futhi kubangele ukuwohloka kokuqhekeka noma kwe-oxidative kwama-polymer angancibiliki abe yizingcezu ezincibilika emanzini, akhiqize izinhlanganisela ezintsha zamangqamuzana (CH4), CO2 kanye ne-H2O) kuze kube ukubola kokugcina.
Ngokuvamile kunemibono emibili mayelana nendlela ye-biodegradation yezinto ze-polymer eziholela ekuwohlokeni kwe-biodegradation.Okunye ukusika okuhlaselayo kusukela ekugcineni kweketango.Ngakho-ke, izakhiwo zesakhiwo sezinto zokwakha, njengokubunjwa, ukwakheka kweketango eliyinhloko neseceleni, ubukhulu bamaqembu okuphela, kanye nokuba khona noma ukungabikho kokuphikiswa kwe-steric yendawo, yizici ezibalulekile ezithinta ukusebenza kwazo kokuwohloka.Phakathi kwazo, izakhiwo eziyinhloko zamaketanga zinomthelela omkhulu.Uma iketango eliyinhloko le-polymer liqukethe amabhondi akhishwa kalula nge-hydrolyzed, azobe enziwe nge-biodegraded kalula.Okwesibili, uma umgogodla uguquguquka, izinga lokuwohloka lizoshesha kakhulu, kanti uma umgogodla uqinile futhi uhlelekile, izinga lokuwohloka lizohamba kancane.
I-biodegradability yezinto ze-polymer iyancishiswa ngamagatsha kanye nokuxhumanisa.Isibonelo, ukwethulwa kwamaqembu e-hydrophobic ekupheleni kwe-polylactic acid (PLA) iketanga lamangqamuzana kunganciphisa izinga lokuguguleka esigabeni sokuqala sokuwohloka.Lokhu kungenxa yokuthi enqubweni yokuqala yokuwohloka, ukuguguleka kwe-PLA kuncike kakhulu ekwakhekeni kokuphela kweketango lamangqamuzana, futhi ukwengezwa kwamaqembu e-hydrophobic kuholela ekwehleni kwezinga lokuguguleka kwayo.Ngaphezu kwalokho, abanye abacwaningi baye bahlola ukwakheka kwamakhemikhali ama-polymers kanye nesisindo samangqamuzana esihlobene sezinto ezidlala indima ebalulekile ekuwohlokeni kwawo.
2. Ukuthuthukiswa kwamapulasitiki angaboli
Isiqondiso sokuthuthukiswa kwamapulasitiki angaboli ngokuzayo singaba kanje:
(1) amapulasitiki abolayo alungiswa ngokutadisha indlela yokuwohloka kwemvelo yama-polymers awonakele, kanye ne-block copolymerization yamapulasitiki angaboli nama-polymer akhona avamile, ama-microbial polymers nama-polymers emvelo kwafundwa futhi kwathuthukiswa.
(2) ukucinga ama-microorganisms angakhiqiza amapulasitiki e-polymer, ukuhlola ama-polymer amasha, ukuhlaziya indlela yawo yokuhlanganisa ngokuningiliziwe, ukuthuthukisa ukukhiqiza kwawo ngezindlela ezikhona nezindlela zobunjiniyela bezakhi zofuzo, nokutadisha izindlela eziphumelelayo zokutshala amagciwane.
(3) qaphela ukulawulwa kwezinga lokuwohloka, ukuthuthukisa abagqugquzeli bokwehliswa kwesithunzi abaphumelelayo kanye nezinzinzisi ukuze kuthuthukiswe ukusebenza kokuwohloka kwemvelo kwamapulasitiki awonakaliswayo, ukunciphisa izindleko zabo, nokwandisa ukusetshenziswa kwemakethe.
(4) cwaninga futhi usungule incazelo ehlanganisiwe yamapulasitiki awonakalayo, anothise futhi athuthukise indlela yokuhlola yokuwohloka kwemvelo, futhi aqonde ngokwengeziwe indlela yokuwohloka.
Isikhathi sokuthumela: Aug-13-2019