Okubizwa ngokuthii-polyurethaneIsifinyezo se-polyurethane, esakhiwa ukusabela kwama-polyisocyanates nama-polyols, futhi siqukethe amaqembu amaningi aphindaphindwayo ama-amino ester (- NH-CO-O -) ku-molecular chain. Kuma-polyurethane resins angempela ahlanganisiwe, ngaphezu kweqembu lama-amino ester, kukhona namaqembu afana ne-urea ne-biuret. Ama-Polyols angamalungu ama-molecule e-long-chain anamaqembu e-hydroxyl ekugcineni, abizwa ngokuthi “izingxenye ze-soft chain”, kuyilapho ama-polyisocyanates ebizwa ngokuthi “izingxenye ze-hard chain”.
Phakathi kwama-resin e-polyurethane akhiqizwa yizingxenye ze-chain ezithambile neziqinile, amaphesenti amancane kuphela angama-amino acid esters, ngakho-ke kungase kungafaneleki ukuwabiza ngokuthi i-polyurethane. Ngomqondo obanzi, i-polyurethane iyisengezo se-isocyanate.
Izinhlobo ezahlukene zama-isocyanates zisabela ngama-polyhydroxy compounds ukuze zikhiqize izakhiwo ezahlukene ze-polyurethane, ngaleyo ndlela zithole izinto ze-polymer ezinezakhiwo ezahlukene, njengepulasitiki, irabha, izembozo, imicu, izinamathiseli, njll. Irabha ye-polyurethane
Irabha ye-polyurethane ingeyohlobo olukhethekile lwerabha, olwenziwa yi-polyether noma i-polyester ephendulayo nge-isocyanate. Kunezinhlobo eziningi ngenxa yezinhlobo ezahlukene zezinto zokusetshenziswa, izimo zokusabela, kanye nezindlela zokuxhumanisa. Ngokombono wesakhiwo samakhemikhali, kunezinhlobo ze-polyester ne-polyether, futhi ngokombono wendlela yokucubungula, kunezinhlobo ezintathu: uhlobo lokuxuba, uhlobo lokukhipha, kanye nohlobo lwe-thermoplastic.
Irabha ye-polyurethane yokwenziwa ngokuvamile yenziwa nge-polyester eqondile noma i-polyether ene-diisocyanate ukuze yakhe i-prepolymer enesisindo esincane sama-molecule, bese ifakwa ku-chain extension reaction ukuze ikhiqize i-polymer enesisindo sama-molecule esiphezulu. Ngemuva kwalokho, ama-agent afanele okuxhumanisa ayangezwa futhi ashiswe ukuze ayilungise, abe irabha evulcanized. Le ndlela ibizwa ngokuthi i-prepolymerization noma indlela yezinyathelo ezimbili.
Kungenzeka futhi ukusebenzisa indlela yesinyathelo esisodwa - ukuxuba ngqo i-polyester eqondile noma i-polyether nama-diisocyanates, izandisi zeketanga, kanye nama-agent okuxhumanisa ukuze kuqalwe ukusabela futhi kukhiqizwe irabha ye-polyurethane.
Ingxenye ye-A kuma-molecule e-TPU yenza amaketanga e-macromolecule kube lula ukuwazungeza, inika irabha ye-polyurethane ukuqina okuhle, inciphise iphuzu lokuthambisa kanye nephuzu lesibili lokuguquka kwe-polymer, futhi inciphise ubulukhuni bayo kanye namandla okusebenza. Ingxenye ye-B izobopha ukujikeleza kwamaketanga e-macromolecule, ibangele ukuthi iphuzu lokuthambisa kanye nephuzu lesibili lokuguquka kwe-polymer likhuphuke, okuholela ekwandeni kobulukhuni kanye namandla okusebenza, kanye nokwehla kokuqina. Ngokulungisa isilinganiso se-molar phakathi kuka-A no-B, ama-TPU anezakhiwo ezahlukene zokusebenza angakhiqizwa. Isakhiwo sokuxhumanisa se-TPU akumele sicabangele ukuxhumanisa okuyinhloko kuphela, kodwa futhi nokuxhumanisa okwesibili okwakhiwa yizibopho ze-hydrogen phakathi kwama-molecule. Isibopho sokuxhumanisa esiyinhloko se-polyurethane sihlukile esakhiweni se-vulcanization serabha ye-hydroxyl. Iqembu layo le-amino ester, iqembu le-biuret, iqembu le-urea formate kanye namanye amaqembu asebenzayo ahlelwe ngesigaba seketanga esiqinile nesijwayelekile, okuholela esakhiweni senethiwekhi esivamile serabha, esinokumelana okuhle kakhulu kokuguguleka kanye nezinye izakhiwo ezinhle kakhulu. Okwesibili, ngenxa yokuba khona kwamaqembu amaningi asebenzayo ahlangene kakhulu njengeqembu le-urea noma le-carbamate ngerabha ye-polyurethane, izibopho ze-hydrogen ezakhiwe phakathi kwamaketanga ama-molecule zinamandla aphezulu, kanti izibopho zesibili zokuxhumanisa ezakhiwe yizibopho ze-hydrogen nazo zinomthelela omkhulu ezimpahleni zerabha ye-polyurethane. Ukuxhumanisa kwesibili kwenza irabha ye-polyurethane ibe nezici ze-thermosetting elastomers ngakolunye uhlangothi, kanti ngakolunye uhlangothi, lokhu kuxhumanisa akuxhumene ngempela, okwenza kube ukuxhumanisa okubonakalayo. Isimo sokuxhumanisa sincike ekushiseni. Njengoba izinga lokushisa landa, lokhu kuxhumanisa kuyancipha kancane kancane futhi kunyamalale. I-polymer inoketshezi oluthile futhi ingacutshungulwa nge-thermoplastic. Lapho izinga lokushisa lehla, lokhu kuxhumanisa kuyalulama kancane kancane futhi kwakheke futhi. Ukwengezwa kwenani elincane lokugcwalisa kwandisa ibanga phakathi kwama-molecule, kunciphisa ikhono lokwakha izibopho ze-hydrogen phakathi kwama-molecule, futhi kuholela ekwehleni okukhulu kwamandla. Ucwaningo lukhombisile ukuthi ukuhleleka kokuzinza kwamaqembu ahlukahlukene asebenzayo ngerabha ye-polyurethane kusukela phezulu kuya phansi yilokhu: i-ester, i-ether, i-urea, i-carbamate, kanye ne-biuret. Ngesikhathi senqubo yokuguga kwerabha ye-polyurethane, isinyathelo sokuqala ukuphulwa kwezibopho ezixhumanisayo phakathi kwe-biuret ne-urea, kulandelwe ukuphulwa kwezibopho ze-carbamate ne-urea, okungukuthi, ukuphulwa kweketanga eliyinhloko.
01 Ukuthambisa
Ama-elastomer e-polyurethane, njengezinto eziningi ze-polymer, athambisa emazingeni okushisa aphezulu futhi aguqukele esimweni sokunwebeka aye esimweni sokugeleza okuqinile, okuholela ekwehleni okusheshayo kwamandla omshini. Ngokombono wamakhemikhali, izinga lokushisa lokunwebeka lokunwebeka lincike kakhulu ezintweni ezifana nokwakheka kwamakhemikhali, isisindo sama-molecule esihlobene, kanye nobuningi obuhlanganisayo.
Ngokuvamile, ukwandisa isisindo sama-molecule esihlobene, ukwandisa ukuqina kwengxenye eqinile (njengokufaka indandatho ye-benzene ku-molecule) kanye nokuqukethwe kwengxenye eqinile, kanye nokwandisa ubuningi bokuxhumanisa konke kuzuzisa ekwandiseni izinga lokushisa lokuthambisa. Kuma-elastomer e-thermoplastic, isakhiwo sama-molecule siqondile kakhulu, futhi izinga lokushisa lokuthambisa le-elastomer nalo liyakhula lapho isisindo sama-molecule esihlobene sikhuphuka.
Kuma-elastomer e-polyurethane axhumene ne-cross-linked, ubuningi bokuxhumanisa bunomthelela omkhulu kunesisindo sama-molecule esihlobene. Ngakho-ke, lapho kukhiqizwa ama-elastomer, ukwandisa ukusebenza kwama-isocyanates noma ama-polyol kungakha isakhiwo sokuxhumanisa samakhemikhali senethiwekhi esizinzile ngokushisa kwamanye ama-molecule anwebekayo, noma ukusebenzisa izilinganiso ze-isocyanate eziningi kakhulu ukwakha isakhiwo sokuxhumanisa esizinzile se-isocyanate emzimbeni onwebekayo kuyindlela enamandla yokuthuthukisa ukumelana nokushisa, ukumelana ne-solvent, kanye namandla omshini we-elastomer.
Uma i-PPDI (p-phenyldiisocyanate) isetshenziswa njengezinto zokusetshenziswa, ngenxa yokuxhumana okuqondile kwamaqembu amabili e-isocyanate nendandatho ye-benzene, ingxenye eqinile eyakhiwe inokuqukethwe okuphezulu kwendandatho ye-benzene, okuthuthukisa ukuqina kwengxenye eqinile ngaleyo ndlela kuthuthukisa ukumelana nokushisa kwe-elastomer.
Ngokombono ongokwenyama, izinga lokushisa lokuthambisa lama-elastomer lincike ezingeni lokuhlukaniswa kwe-microphase. Ngokusho kwemibiko, izinga lokushisa lokuthambisa lama-elastomer angadluli ekuhlukanisweni kwe-microphase liphansi kakhulu, kanti izinga lokushisa lokucubungula lingaba ngu-70 ℃ kuphela, kuyilapho ama-elastomer adlula ekuhlukanisweni kwe-microphase angafinyelela ku-130-150 ℃. Ngakho-ke, ukwandisa izinga lokuhlukaniswa kwe-microphase kuma-elastomer kungenye yezindlela ezisebenzayo zokuthuthukisa ukumelana kwawo nokushisa.
Izinga lokuhlukaniswa kwe-microphase kwama-elastomer lingathuthukiswa ngokushintsha ukusatshalaliswa kwesisindo sama-molecule esihlobene sezingxenye zeketanga kanye nokuqukethwe kwezingxenye zeketanga eziqinile, ngaleyo ndlela kuthuthukiswe ukumelana kwazo nokushisa. Iningi labacwaningi likholelwa ukuthi isizathu sokuhlukaniswa kwe-microphase ku-polyurethane ukungavumelani kwe-thermodynamic phakathi kwezingxenye ezithambile neziqinile. Uhlobo lwe-chain extender, ingxenye eqinile kanye nokuqukethwe kwayo, uhlobo lwengxenye ethambile, kanye nokubopha kwe-hydrogen konke kunomthelela omkhulu kukho.
Uma kuqhathaniswa nezandisi ze-diol chain, izandisi ze-diamine chain ezifana ne-MOCA (3,3-dichloro-4,4-diaminodiphenylmethane) kanye ne-DCB (3,3-dichloro-biphenylenediamine) zakha amaqembu amaningi e-polar amino ester kuma-elastomers, futhi izibopho ze-hydrogen eziningi zingakhiwa phakathi kwezingxenye eziqinile, okwandisa ukusebenzisana phakathi kwezingxenye eziqinile futhi kuthuthukiswe izinga lokuhlukaniswa kwe-microphase kuma-elastomers; Izandisi ze-symmetric aromatic chain ezifana ne-p, i-p-dihydroquinone, kanye ne-hydroquinone ziwusizo ekwenzeni kube lula futhi kuhlanganiswe kahle kwezingxenye eziqinile, ngaleyo ndlela kuthuthukiswe ukuhlukaniswa kwe-microphase kwemikhiqizo.
Izingxenye ze-amino ester ezakhiwe yi-aliphatic isocyanates zinokuhambisana okuhle nezingxenye ezithambile, okuholela ekutheni izingxenye eziningi eziqinile zincibilike ezingxenyeni ezithambile, okunciphisa izinga lokuhlukaniswa kwe-microphase. Izingxenye ze-amino ester ezakhiwe yi-aromatic isocyanates azivumelani kahle nezingxenye ezithambile, kuyilapho izinga lokuhlukaniswa kwe-microphase liphakeme. I-Polyolefin polyurethane inesakhiwo sokuhlukaniswa kwe-microphase esicishe siphelele ngenxa yokuthi ingxenye ethambile ayakhi izibopho ze-hydrogen futhi izibopho ze-hydrogen zingenzeka kuphela engxenyeni eqinile.
Umphumela wokubopha kwe-hydrogen endaweni yokuthambisa yama-elastomer nawo ubalulekile. Nakuba ama-polyether nama-carbonyl engxenyeni ethambile angakha inani elikhulu lezibopho ze-hydrogen ne-NH engxenyeni eqinile, futhi kwandisa izinga lokushisa lokuthambisa lama-elastomer. Kuqinisekisiwe ukuthi izibopho ze-hydrogen zisagcina u-40% ku-200 ℃.
02 Ukubola kokushisa
Amaqembu e-amino ester abhekana nokubola okulandelayo emazingeni okushisa aphezulu:
- RNHCOOR – RNC0 HO-R
- RNHCOOR – RNH2 CO2 ene
- RNHCOOR – RNHR CO2 ene
Kunezinhlobo ezintathu eziyinhloko zokubola kokushisa kwezinto ezisekelwe ku-polyurethane:
① Ukwakha ama-isocyanates nama-polyol okuqala;
② α— Isibopho se-oxygen esisekelweni se-CH2 siyaphuka futhi sihlangane nesibopho se-hydrogen esisodwa esise-CH2 yesibili ukuze sakhe ama-amino acid nama-alkenes. Ama-amino acid ayabola abe yi-amine eyodwa eyinhloko kanye ne-carbon dioxide:
③ Ifomu 1 i-amine yesibili kanye ne-carbon dioxide.
Ukubola kokushisa kwesakhiwo se-carbamate:
I-Aryl NHCO I-Aryl, ~ 120 ℃;
I-N-alkyl-NHCO-aryl,~180 ℃;
I-Aryl NHCO n-alkyl,~200 ℃;
I-N-alkyl-NHCO-n-alkyl,~250 ℃.
Ukuzinza kokushisa kwama-amino acid esters kuhlobene nezinhlobo zezinto zokuqala ezifana nama-isocyanates nama-polyol. Ama-isocyanates e-aliphatic aphakeme kune-aromatic isocyanates, kuyilapho ama-fatty alcohols aphezulu kune-aromatic alcohols. Kodwa-ke, izincwadi zibika ukuthi izinga lokushisa lokubola kokushisa kwama-amino acid esters e-aliphatic liphakathi kuka-160-180 ℃, kanti elama-aromatic amino acid esters liphakathi kuka-180-200 ℃, okungavumelani nedatha engenhla. Isizathu singase sihlobene nendlela yokuhlola.
Eqinisweni, i-aliphatic CHDI (1,4-cyclohexane diisocyanate) kanye ne-HDI (hexamethylene diisocyanate) zinokumelana nokushisa okungcono kune-aromatic MDI kanye ne-TDI evame ukusetshenziswa. Ikakhulukazi i-trans CHDI enesakhiwo esilinganayo iye yaqashelwa njenge-isocyanate engamelana nokushisa kakhulu. Ama-polyurethane elastomers alungiselelwe ngawo anokucutshungulwa okuhle, ukumelana okuhle kakhulu kwe-hydrolysis, izinga lokushisa eliphakeme lokuthambisa, izinga lokushisa eliphansi lokushintsha kwengilazi, i-hysteresis ephansi yokushisa, kanye nokumelana okuphezulu kwe-UV.
Ngaphezu kweqembu lama-amino ester, ama-polyurethane elastomers nawo anamaqembu asebenzayo njenge-urea formate, i-biuret, i-urea, njll. La maqembu angabola ngokushisa emazingeni okushisa aphezulu:
I-NHCONCOO – (i-aliphatic urea formate), 85-105 ℃;
- NHCONCOO – (i-aromatic urea formate), ebangeni lokushisa elingu-1-120 ℃;
- I-NHCONCONH – (i-aliphatic biuret), ekushiseni okusukela ku-10 ° C kuya ku-110 ° C;
I-NHCONCONH – (i-biuret enuka kamnandi), 115-125 ℃;
I-NHCONH – (i-urea ye-aliphatic), 140-180 ℃;
- NHCONH – (i-urea enuka kamnandi), 160-200 ℃;
Indandatho ye-Isocyanurate>270 ℃.
Izinga lokushisa lokubola kokushisa kwe-formate esekelwe ku-biuret kanye ne-urea liphansi kakhulu kunele-aminoformate kanye ne-urea, kuyilapho i-isocyanurate inokuqina kokushisa okungcono kakhulu. Ekukhiqizweni kwama-elastomer, ama-isocyanate amaningi angasabela kakhulu kuma-aminoformate kanye ne-urea akhiwe ukuze akhe izakhiwo ezixhumene ne-urea ezisekelwe ku-urea kanye ne-biuret. Nakuba zingathuthukisa izakhiwo ze-elastomer, azizinzile kakhulu ekushiseni.
Ukuze kuncishiswe amaqembu angazinzile okushisa njenge-biuret kanye ne-urea formate kuma-elastomers, kubalulekile ukucabangela isilinganiso sawo sezinto zokusetshenziswa kanye nenqubo yokukhiqiza. Kufanele kusetshenziswe izilinganiso ze-isocyanate ezidlulele, futhi ezinye izindlela kufanele zisetshenziswe ngangokunokwenzeka ukuze kuqale kwakhiwe izindandatho ze-isocyanate ezingaphelele ezintweni zokusetshenziswa (ikakhulukazi ama-isocyanate, ama-polyol, kanye ne-chain extenders), bese zifakwa kwi-elastomer ngokwezinqubo ezijwayelekile. Lena isibe yindlela esetshenziswa kakhulu yokukhiqiza ama-polyurethane elastomers angamelani nokushisa futhi angamelani nomlilo.
03 I-Hydrolysis kanye ne-thermal oxidation
Ama-elastomer e-polyurethane athambekele ekuboleni kokushisa ezigabeni zawo eziqinile kanye nezinguquko zamakhemikhali ezihambisanayo ezigabeni zawo ezithambile emazingeni okushisa aphezulu. Ama-elastomer e-polyester anokumelana okuncane kwamanzi kanye nokuthambekela okukhulu koku-hydrolyze emazingeni okushisa aphezulu. Isikhathi senkonzo ye-polyester/TDI/diamine singafinyelela ezinyangeni ezingu-4-5 ku-50 ℃, amasonto amabili kuphela ku-70 ℃, kanye nezinsuku ezimbalwa kuphela ezingaphezu kuka-100 ℃. Ama-Ester bonds angabola abe ama-acid nama-alcohol ahambisanayo uma evezwa emanzini ashisayo kanye nomusi, kanti amaqembu e-urea nama-amino ester kuma-elastomer nawo angabhekana nokusabela kwe-hydrolysis:
I-RCOOR H20- → I-RCOOH HOR
Utshwala be-Ester
I-RNHCONHR eyodwa H20- → I-RXHCOOH H2NR -
I-Ureamide
I-RNHCOOR-H20 eyodwa- → I-RNCOOH HOR -
I-Amino formate ester I-Amino formate alcohol
Ama-elastomer asekelwe ku-polyether anokuqina okuphansi kwe-thermal oxidation, kanye nama-elastomer asekelwe ku-ether α- I-hydrogen e-athomu yekhabhoni i-oxidation kalula, yakha i-hydrogen peroxide. Ngemva kokubola nokuqhekeka okwengeziwe, ikhiqiza ama-oxide radicals kanye nama-hydroxyl radicals, agcina ebola abe ama-formates noma ama-aldehydes.
Ama-polyester ahlukene awathinti kangako ukumelana nokushisa kwama-elastomer, kuyilapho ama-polyether ahlukene enethonya elithile. Uma kuqhathaniswa ne-TDI-MOCA-PTMEG, i-TDI-MOCA-PTMEG inezinga lokugcina amandla okudonswa elingu-44% kanye no-60% ngokulandelana uma iguga ku-121 ℃ izinsuku ezingu-7, kanti elokugcina lingcono kakhulu kunelokuqala. Isizathu kungaba ukuthi ama-molecule e-PPG anezinhlayiya ezinamagatsha, ezingahambisani nokuhlelwa okuvamile kwama-molecule anwebekayo futhi zinciphisa ukumelana nokushisa komzimba onwebekayo. I-oda lokuzinza kokushisa kwama-polyether yileli: PTMEG>PEG>PPG.
Amanye amaqembu asebenzayo kuma-elastomer e-polyurethane, njenge-urea ne-carbamate, nawo abhekana nokusabela kwe-oxidation kanye ne-hydrolysis. Kodwa-ke, iqembu le-ether yilona elifakwa kalula i-oxidation, kanti iqembu le-ester yilona elifakwa kalula i-hydrolyzed. Uhlelo lokumelana kwabo ne-antioxidant kanye ne-hydrolysis yilolu:
Umsebenzi we-antioxidant: ama-esters>urea>carbamate>ether;
Ukumelana ne-hydrolysis: i-ester
Ukuze kuthuthukiswe ukumelana nokushiswa kwe-polyether polyurethane kanye nokumelana ne-hydrolysis kwe-polyester polyurethane, kunezelwa nezithasiselo, njengokwengeza i-1% phenolic antioxidant Irganox1010 ku-PTMEG polyether elastomer. Amandla okudonsa ale elastomer angandiswa ngokuphindwe ka-3-5 uma kuqhathaniswa nokungenawo ama-antioxidants (imiphumela yokuhlola ngemva kokuguga ku-1500C amahora angu-168). Kodwa akuwona wonke ama-antioxidant anethonya kuma-polyurethane elastomer, yi-phenolic 1rganox 1010 kanye ne-TopanOl051 kuphela (i-phenolic antioxidant, i-hindraised amine light stabilizer, i-benzotriazole complex) enemiphumela ebalulekile, futhi eyokuqala iyona engcono kakhulu, mhlawumbe ngoba ama-phenolic antioxidants anokuhambisana okuhle nama-elastomer. Kodwa-ke, ngenxa yendima ebalulekile yamaqembu e-phenolic hydroxyl endleleni yokuzinzisa ama-antioxidants e-phenolic, ukuze kugwenywe ukusabela kanye "nokwehluleka" kwaleli qembu le-phenolic hydroxyl elinamaqembu e-isocyanate ohlelweni, isilinganiso sama-isocyanate kuma-polyol akufanele sibe sikhulu kakhulu, futhi ama-antioxidants kumele afakwe kuma-prepolymers kanye nama-chain extenders. Uma engezwa ngesikhathi sokukhiqizwa kwama-prepolymers, kuzothinta kakhulu umphumela wokuzinzisa.
Izithasiselo ezisetshenziselwa ukuvimbela i-hydrolysis ye-polyester polyurethane elastomers ikakhulukazi ama-carbodiimide compounds, asabela nama-carboxylic acid akhiqizwa yi-ester hydrolysis kuma-molecule e-polyurethane elastomer ukuze akhiqize ama-acyl urea derivatives, okuvimbela i-hydrolysis eyengeziwe. Ukwengezwa kwe-carbodiimide engxenyeni enkulu engu-2% kuya ku-5% kungandisa ukuzinza kwamanzi kwe-polyurethane izikhathi ezingu-2-4. Ngaphezu kwalokho, i-tert butyl catechol, i-hexamethylenetetramine, i-azodicarbonamide, njll. nazo zinemiphumela ethile yokulwa ne-hydrolysis.
04 Izici zokusebenza eziyinhloko
Ama-elastomer e-polyurethane angama-copolymer ajwayelekile ama-multi block, anamaketanga e-molecule akhiwe yizingxenye eziguquguqukayo ezinezinga lokushisa lokuguquka kwengilazi elingaphansi kunezinga lokushisa legumbi kanye nezingxenye eziqinile ezinezinga lokushisa lokuguquka kwengilazi eliphakeme kunezinga lokushisa legumbi. Phakathi kwawo, ama-polyol e-oligomeric akha izingxenye eziguquguqukayo, kuyilapho ama-diisocyanates kanye nezinwebi ze-molecule encane zakha izingxenye eziqinile. Isakhiwo esihlanganisiwe sezingxenye zeketanga eziguquguqukayo neziqinile sinquma ukusebenza kwazo okuhlukile:
(1) Ububanzi bobulukhuni berabha evamile buvame ukuba phakathi kweShaoer A20-A90, kuyilapho ububanzi bobulukhuni bepulasitiki bungaba yiShaoer A95 Shaoer D100. Ama-elastomer e-polyurethane angafinyelela phansi njengeShaoer A10 futhi afinyelele phezulu njengeShaoer D85, ngaphandle kwesidingo sosizo lokugcwalisa;
(2) Amandla aphezulu kanye nokunwebeka kusengakwazi ukugcinwa ngaphakathi kobubanzi obukhulu bobulukhuni;
(3) Ukumelana okuhle kakhulu nokuguguleka, okuphindwe kabili kuya kweshumi kunerabha yemvelo;
(4) Ukumelana okuhle kakhulu namanzi, uwoyela, namakhemikhali;
(5) Ukumelana nomthelela omkhulu, ukumelana nokukhathala, kanye nokumelana nokudlidliza, okufanele ukusetshenziswa kokugoba okuvamise kakhulu;
(6) Ukumelana okuhle nokushisa okuphansi, kanye nokuqhekeka kokushisa okuphansi okungaphansi kuka -30 ℃ noma -70 ℃;
(7) Isebenza kahle kakhulu ekushiseni, futhi ngenxa yokushisa kwayo okuphansi, inomphumela omuhle wokushisa uma kuqhathaniswa nerabha nepulasitiki;
(8) Ukuhambisana kahle kwezinto eziphilayo kanye nezakhiwo zokulwa nokuvuvukala;
(9) Ukushisa okuhle kakhulu kukagesi, ukumelana nesikhunta, kanye nokuqina kwe-UV.
Ama-elastomer e-polyurethane angakhiwa kusetshenziswa izinqubo ezifanayo nerabha evamile, njengokwenziwa kwepulasitiki, ukuxuba, kanye nokuhlanganiswa kwe-vulcanization. Angabunjwa futhi ngesimo serabha eliwuketshezi ngokuthulula, ukubumba nge-centrifugal, noma ngokufafaza. Angenziwa futhi abe izinto ezi-granular futhi akhiwe kusetshenziswa umjovo, i-extrusion, i-rolling, i-blow molding, nezinye izinqubo. Ngale ndlela, ayigcini nje ngokuthuthukisa ukusebenza kahle komsebenzi, kodwa futhi ithuthukisa ukunemba kobukhulu kanye nokubukeka komkhiqizo.
Isikhathi sokuthunyelwe: Disemba-05-2023