Uphuhliso kunye nokusetyenziswa biodegradable polymer iiplastiki, iiplastiki biodegradable luhlobo olutsha uhlobo umsebenzi wokuthotywa kwemathiriyeli polymer, kwinkqubo yokusetyenziswa, inento yokwenza nohlobo olufanayo lweplastiki eqhelekileyo kunye nempilo ehambelanayo kunye nokusebenza isicelo efanelekileyo, kwaye emva komsebenzi wayo opheleleyo, izinto ezinokuthi zithotywe ngokukhawuleza kwiimeko zendalo zendalo zibe lula ukuba zinikwe amaqhekeza okusingqongileyo okanye zityunyuziwe, kwaye ngokuhamba kwexesha ukuthotywa okungaphezulu kube ekugqibeleni iimveliso ze-oxidation (CO2 kunye namanzi), zibuyele kwindalo.
Uphuhliso kunye nokusetyenziswa kwe-biodegradableiiplastiki zepolymer, iiplastiki ze-biodegradable luhlobo olutsha olunomsebenzi wokuthotywa kwezinto zepolymer, kwinkqubo yokusetyenziswa, inento yokwenza nohlobo olufanayo lweplastiki eqhelekileyo kunye nempilo ehambelanayo kunye nokusebenza kwesicelo esifanelekileyo, kwaye emva komsebenzi wayo opheleleyo, izinto eziphathekayo. kunokonakaliswa ngokukhawuleza kwimekobume yendalo ibe lula ukunikwa amaqhekeza okusingqongileyo okanye ukutyunyuzwa, kwaye ngokuhamba kwexesha ukonakaliswa okungaphezulu kuye ekugqibeleni kube ziimveliso ze-oxidation (CO2 kunye namanzi), zibuyele kwindalo.
Ngokusekwe kungcoliseko lokusingqongileyo olubangelwa yinkunkuma yeplastiki, kunye nemfuno yokukhuselwa kwendalo kunye neemfuno zabantu, kungxamisekile ukufunda imathiriyeli yepolymer eyonakalisayo.Ngexesha elithile naphantsi kweemeko ezithile zokusingqongileyo, ulwakhiwo lweekhemikhali zeeplastiki eziguquguqukayo ziya kutshintsha.Ngokwezizathu zotshintsho kulwakhiwo lwekhemikhali, iiplastiki ezinokonakala ngokwezinto eziphilayo zinokwahlulwa zibe ngamacandelo amabini: iiplastiki eziguquguqukayo kunye neeplastiki ezinokonakala.
1. Indlela yokuthotywa kweeplastiki ezonakeleyo
Ngokuqhelekileyo, iplastiki eyonakalisayo ibhekisela kuhlobo lweplastiki enokuthi iboliswe kwiimolekyuli ezincinci ngokusebenzisa i-microorganisms emhlabeni okanye kwimitha yelanga.Kufuneka ihlangabezane neemfuno zokusetyenziswa kweemveliso kwaye kulula ukuyiqhuba ngesiseko iipropati ezinokubola.Ubume besenzo sokukhanya kwelanga kwizinto ze-polymer yimpembelelo ebanzi yokukhanya kwe-ultraviolet ekukhanyeni kwelanga kunye ne-oksijini emoyeni, ngoko ikwabizwa ngokuba yi-photooxidation degradation.Thatha i-polyolefin njengomzekelo ukuchaza indlela yokuthotywa kwe-photooxidation.Eyona nto ibalulekileyo, i-photooxidation ibangela ukuqhekeka kwekhonkco okanye ukuphambana kweepolymers, kwaye amanye amaqela asebenzayo aneoksijini, afana ne-carboxylic acid, iperoxides, iiketones kunye neealcohols, zenziwa kule nkqubo.Iintsalela ze-Catalyst kwiipolymers kunye nokuqaliswa kweperoxide kunye namaqela e-carboxyl angeniswe ngexesha lokulungiswa kweyona mithombo iphambili yokuwohloka.
Ngaphantsi kwesenzo se-microorganisms (ikakhulukazi i-fungi, ibhaktheriya okanye i-algae, njl.), ii-polymers zinokuchithwa okanye zenziwe nge-metabolized ukuze zenze utshintsho kwisakhiwo sabo samakhemikhali kunye nokunciphisa ubunzima be-molecular.Indlela yokusebenza inokohlulwa ikakhulu kwiimeko ezimbini :
(1) isenzo sebhayoloji.Oko kukuthi, emva kokukhukuliseka kweemveliso zeplastiki nge-microorganisms, ukukhula kweeseli zebhayoloji, ukukhuthaza ukubola kweepolymers, ionization okanye iproton, esi senzo somzimba kwipolymer sibangele umonakalo womatshini, ubunzima obuphezulu bemolekyuli yepolymer ibe ngamaqhekeza e-oligomer, ukuze ukufezekisa injongo yokuthotywa komzimba.
(2) isenzo se-biochemical - isenzo esithe ngqo se-enzymes.Le meko ibangelwa ukukhukuliseka kwee-enzymes ezifihliweyo ngumngundo okanye ibhaktheriya, ekhokelela ekuqhekekeni okanye ekuqhekekeni kwe-oxidative yeeplastiki, kwaye ibangele ukuhlukana okanye ukuchithwa kwe-oxidative yeepholima ezinganyibilikiyo zibe ngamaqhekeza anyibilikayo emanzini, ukuvelisa iikhompawundi ezincinci ze-molecular (CH4), CO2 kunye ne-H2O) kude kube ngukubola kokugqibela.
Kukho iingqikelelo ezimbini ngokubanzi malunga nenkqubo ye-biodegradation yemathiriyeli yepolymer ekhokelela kwi-biodegradation.Enye i-invasive cut from the end of the chain.Ngako oko, iipropati zesakhiwo sezinto eziphathekayo, ezifana nokubunjwa, ukwakhiwa kwekhonkco kunye necala, ubukhulu bamaqela okugqibela, kunye nobukho okanye ukungabikho kokumelana ne-spatial steric, zizinto eziphambili ezichaphazela ukuthotywa kwazo.Phakathi kwabo, iipropati eziphambili zekhonkco zinempembelelo enkulu.Ukuba ikhonkco eliphambili lepolymer liqukethe iibhondi ezihlanjululwa ngokulula nge-hydrolyzed, iya kuba lula i-biodegraded.Okwesibini, ukuba umqolo uguquguqukayo, izinga lokuthotywa liya kukhawuleza ngokukhawuleza, kanti ukuba umqolo uqinile kwaye ulungelelanise, izinga lokunciphisa liya kuhamba.
I-biodegradability yezinto ze-polymer iyancitshiswa ngama-branching kunye ne-crosslinking.Ngokomzekelo, ukuqaliswa kwamaqela e-hydrophobic ekupheleni kwe-polylactic acid (PLA) i-molecular chain inokunciphisa izinga lokukhukuliseka kwinqanaba lokuqala lokuthotywa.Oku kungenxa yokuba kwinkqubo yokuthotywa komgangatho, ukhukuliseko lwe-PLA luxhomekeke ikakhulu kulwakhiwo lwe-molecular chain end, kwaye ukongezwa kwamaqela e-hydrophobic kukhokelela ekwehleni kwezinga lokukhukuliseka kwayo.Ukongeza, abanye abaphandi baye bafunda ubume beekhemikhali zeepolymers kunye nobunzima bemolekyuli bezinto ezidlala indima ebalulekileyo ekuthotyweni kwazo.
2. Ukuphuhliswa kweeplastiki ezinokubola
Umkhombandlela wophuhliso lweplastiki enokubola kwixa elizayo ingaba ngolu hlobo lulandelayo:
(1) iiplastiki ze-biodegradable zalungiswa ngokufunda indlela yokuguqulwa kwe-biodegradation yeepolymers ezinokonakala, kunye ne-copolymerization yebhloko yeeplastiki ze-biodegradable kunye neepolima eziqhelekileyo ezikhoyo, iipholima ezincinci kunye neepolima zendalo zafundwa kwaye zaphuhliswa.
(2) ukukhangela ii-microorganisms ezinokuvelisa iiplastiki ze-polymer, ukuphonononga iipolymers ezintsha, ukuhlalutya indlela yazo yokudibanisa ngokubanzi, ukuphucula imveliso yazo ngeendlela ezikhoyo kunye neendlela zobunjineli bemfuza, kunye nokufunda iindlela ezifanelekileyo zokuhlakulela i-microorganisms.
(3) ingqalelo ekulawuleni izinga lokuthotywa, ukuphuhlisa abagqugquzeli bokuthotywa okusebenzayo kunye nezizinzisi ukuphucula ukusebenza kwe-biodegradation yeeplastiki ezinokonakala, ukunciphisa iindleko zabo, kunye nokwandisa ukusetyenziswa kwemarike.
(4) uphando kunye nokuseka inkcazo edibeneyo yeeplastiki ezinokonakala, ukutyebisa kunye nokuphucula indlela yokuvavanya ye-biodegradation, kunye nokuqonda ngakumbi indlela yokunciphisa umgangatho.
Ixesha lokuposa: Aug-13-2019