Okubizwa ngokubai-polyurethanesisifinyezo segama elithi polyurethane, elenziwa yimpendulo ye-polyisocyanates kunye ne-polyols, kwaye liqulathe amaqela amaninzi e-amino ester aphindaphindwayo (- NH-CO-O -) kwi-molecular chain. Kwii-polyurethane resins ezidityanisiweyo, ukongeza kwiqela le-amino ester, kukwakho namaqela afana ne-urea kunye ne-biuret. Ii-Polyols zeze-long-chain molecules ezine-hydroxyl groups ekupheleni, ezibizwa ngokuba "zi-soft chain segments", ngelixa ii-polyisocyanates zibizwa ngokuba "zi-hard chain segments".
Phakathi kwee-resin ze-polyurethane eziveliswa ziingqokelela ze-chain ezithambileyo neziqinileyo, yipesenti encinci kuphela ezi-amino acid esters, ngoko ke kusenokungafanelekanga ukuzibiza ngokuba yi-polyurethane. Ngokubanzi, i-polyurethane sisithako se-isocyanate.
Iindidi ezahlukeneyo ze-isocyanates zisabela kunye nee-polyhydroxy compounds ukuze zenze izakhiwo ezahlukeneyo ze-polyurethane, ngaloo ndlela zifumana izinto ze-polymer ezineempawu ezahlukeneyo, ezifana neeplastiki, irabha, iingubo, iifayibha, izincamathelisi, njl. Irabha ye-polyurethane
Irabha yepolyurethane iluhlobo oluthile lwerabha, eyenziwa yi-reactive polyether okanye i-polyester ene-isocyanate. Kukho iintlobo ezininzi ngenxa yeentlobo ezahlukeneyo zezinto ezikrwada, iimeko zokusabela, kunye neendlela zokudibanisa. Ngokwembono yesakhiwo seekhemikhali, kukho iintlobo zepolyester kunye ne-polyether, kwaye ngokwembono yendlela yokucubungula, kukho iintlobo ezintathu: uhlobo lokuxuba, uhlobo lwe-casting, kunye nohlobo lwe-thermoplastic.
Irabha ye-polyurethane eyenziweyo idla ngokwenziwa nge-polyester ethe ngqo okanye i-polyether ene-diisocyanate ukwenza i-prepolymer enobunzima obuphantsi be-molecular, ethi emva koko ibekwe kwi-chain extension reaction ukuze ivelise i-polymer enobunzima obuphezulu be-molecular. Emva koko, ii-agents ezifanelekileyo zokudibanisa ziyafakwa kwaye zifudunyezwe ukuze zinyangwe, zibe yirabha evulcanized. Le ndlela ibizwa ngokuba yi-prepolymerization okanye indlela ye-two-step.
Kukwanokwenzeka ukusebenzisa indlela yenyathelo elinye - ukuxuba ngokuthe ngqo i-linear polyester okanye i-polyether kunye ne-diisocyanates, ii-chain extenders, kunye nee-crosslinking agents ukuqalisa i-reaction kunye nokuvelisa i-polyurethane rubber.
Icandelo le-A kwiimolekyuli ze-TPU lenza ukuba iitsheyini ze-macromolecular zibe lula ukuzijikelezisa, zinika irabha ye-polyurethane ukuthamba okuhle, zinciphise indawo yokuthamba kunye nendawo yesibini yokutshintsha yepolymer, kwaye zinciphise ubulukhuni bayo kunye namandla oomatshini. Icandelo le-B liza kubopha ukujikeleza kweetsheyini ze-macromolecular, okubangela ukuba indawo yokuthamba kunye nendawo yesibini yokutshintsha yepolymer inyuke, okubangela ukwanda kobulukhuni kunye namandla oomatshini, kunye nokuncipha kokuguquguquka. Ngokulungisa umlinganiselo we-molar phakathi kuka-A no-B, ii-TPU ezineempawu ezahlukeneyo zoomatshini zinokuveliswa. Ulwakhiwo lwe-cross-linking lwe-TPU akufuneki luqwalasele kuphela ukuxhuma okuphambili, kodwa kunye nokudibanisa okwesibini okwenziwe ziibhondi ze-hydrogen phakathi kweemolekyuli. Ukubopha okuphambili kokudibanisa kwe-polyurethane kwahlukile kwisakhiwo se-vulcanization serabha ye-hydroxyl. Iqela layo le-amino ester, iqela le-biuret, iqela le-urea formate kunye namanye amaqela asebenzayo acwangciswe kwicandelo le-chain engqongqo neliqhelekileyo, okubangela isakhiwo senethiwekhi yerabha esiqhelekileyo, esinokuxhathisa ukuguguleka okuhle kunye nezinye iimpawu ezintle. Okwesibini, ngenxa yokubakho kwamaqela amaninzi asebenzayo afana ne-urea okanye amaqela e-carbamate kwirabha ye-polyurethane, iibhondi ze-hydrogen ezenziwe phakathi kwee-molecular chains zinamandla aphezulu, kwaye iibhondi zesibini ezidibanisayo ezenziwe ziibhondi ze-hydrogen nazo zinempembelelo enkulu kwiimpawu zerabha ye-polyurethane. Ukudibanisa okwesibini kwenza irabha ye-polyurethane ibe neempawu ze-thermosetting elastomers kwelinye icala, kwaye kwelinye icala, oku kudibanisa okunqamlezileyo akunxibelelani ngokwenene, okwenza kube kukudibanisa okunqamlezileyo okubonakalayo. Imeko yokudibanisa okunqamlezileyo ixhomekeke kubushushu. Njengoko ubushushu busanda, oku kudibanisa okunqamlezileyo kuyaphela kancinci. I-polymer inobumanzi obuthile kwaye inokusetyenziswa kwi-thermoplastic processing. Xa ubushushu buhla, oku kudibanisa okunqamlezileyo kuyaphinda kubuye kwaye kuphinde kwenzeke kwakhona. Ukongezwa kwenani elincinci le-filler kwandisa umgama phakathi kwee-molecules, kunciphisa amandla okwenza iibhondi ze-hydrogen phakathi kwee-molecules, kwaye kukhokelela ekwehleni okukhulu kwamandla. Uphando lubonise ukuba ulungelelwaniso lokuzinza kwamaqela ahlukeneyo asebenzayo kwirabha ye-polyurethane ukusuka phezulu ukuya ezantsi yi: ester, ether, urea, carbamate, kunye ne-biuret. Ngexesha lenkqubo yokwaluphala kwerabha ye-polyurethane, inyathelo lokuqala kukuqhekeka kweebhondi ezidibanisa i-cross-linking phakathi kwe-biuret kunye ne-urea, kulandele ukuqhekeka kweebhondi ze-carbamate kunye ne-urea, oko kukuthi, ukuqhekeka kwekhonkco eliphambili.
01 Ukuthambisa
Ii-elastomers zePolyurethane, njengezinye izinto ezininzi zepolymer, ziyathamba xa kushushu kakhulu kwaye zitshintshela kwimeko yokuthamba ukuya kwimeko yokuhamba okuxineneyo, nto leyo ebangela ukwehla ngokukhawuleza kwamandla oomatshini. Ngokwembono yeekhemikhali, ubushushu bokuthamba buxhomekeke kakhulu kwizinto ezifana nokwakheka kweekhemikhali, ubunzima beemolekyuli, kunye noxinano oludibanisayo.
Ngokubanzi, ukonyusa ubunzima beemolekyuli, ukonyusa ukuqina kwecandelo eliqinileyo (njengokufaka indandatho yebenzene kwimolekyuli) kunye nomxholo wecandelo eliqinileyo, kunye nokonyusa uxinano oludibanisayo konke kuluncedo ekonyuseni ubushushu bokuthambisa. Kwii-elastomers ze-thermoplastic, ulwakhiwo lweemolekyuli lujolise ngqo, kwaye ubushushu bokuthambisa be-elastomer buyanda xa ubunzima beemolekyuli bunyuswa.
Kwi-cross-linked polyurethane elastomers, uxinano lwe-crosslinking lunempembelelo enkulu kunobunzima beemolekyuli. Ke ngoko, xa kusenziwa ii-elastomers, ukwandisa ukusebenza kwee-isocyanates okanye ii-polyols kunokwenza isakhiwo se-thermally stable network chemical cross-linking structure kwezinye zee-molecules ze-elastic, okanye ukusebenzisa i-isocyanate ratios eninzi ukwenza isakhiwo se-isocyanate esizinzileyo emzimbeni we-elastic yindlela enamandla yokuphucula ukumelana nobushushu, ukumelana ne-solvent, kunye namandla oomatshini e-elastomer.
Xa i-PPDI (p-phenyldiisocyanate) isetyenziswa njengezinto eziluhlaza, ngenxa yoqhagamshelo oluthe ngqo lwamaqela amabini e-isocyanate kwiringi yebenzene, icandelo eliqinileyo elenziweyo linomxholo ophezulu weringi yebenzene, nto leyo ephucula ukuqina kwecandelo eliqinileyo ngaloo ndlela iphucula ukumelana nobushushu kwe-elastomer.
Ngokwembono yomzimba, ubushushu bokuthamba kwee-elastomers buxhomekeke kwinqanaba lokwahlulwa kwe-microphase. Ngokweengxelo, ubushushu bokuthamba kwee-elastomers ezingadlulanga kulwahlulo lwe-microphase buphantsi kakhulu, kunye nobushushu bokucubungula obumalunga ne-70 ℃ kuphela, ngelixa ii-elastomers ezidlula kulwahlulo lwe-microphase zinokufikelela kwi-130-150 ℃. Ke ngoko, ukwandisa izinga lokwahlulwa kwe-microphase kwii-elastomers yenye yeendlela ezisebenzayo zokuphucula ukumelana kwazo nobushushu.
Umlinganiselo wokwahlulwa kwe-microphase ye-elastomers unokuphuculwa ngokutshintsha ukusasazwa kobunzima be-molecular kwiinxalenye ze-chain kunye nomxholo weenxalenye ze-rigid chain, ngaloo ndlela kuphucula ukumelana kwazo nobushushu. Uninzi lwabaphandi lukholelwa ukuba isizathu sokwahlulwa kwe-microphase kwi-polyurethane kukungahambelani kwe-thermodynamic phakathi kweenxalenye ezithambileyo neziqinileyo. Uhlobo lwe-chain extender, i-hard segment kunye nomxholo wayo, uhlobo lwe-soft segment, kunye ne-hydrogen bonding zonke zinempembelelo enkulu kuyo.
Xa kuthelekiswa nezandisi zetyathanga le-diol, izandisi zetyathanga le-diamine ezifana ne-MOCA (3,3-dichloro-4,4-diaminodiphenylmethane) kunye ne-DCB (3,3-dichloro-biphenylenediamine) zenza amaqela e-amino ester e-polar kwi-elastomers, kwaye iibhondi ze-hydrogen ezingaphezulu zinokwenziwa phakathi kwezandisi eziqinileyo, nto leyo eyandisa ukusebenzisana phakathi kwezandisi eziqinileyo kwaye iphucule izinga lokwahlulwa kwe-microphase kwi-elastomers; Izandisi zetyathanga le-aromatic ezilinganayo ezifana ne-p, i-p-dihydroquinone, kunye ne-hydroquinone ziluncedo ekuqheleni nasekupakishweni okuqinileyo kwezandisi eziqinileyo, ngaloo ndlela ziphucula ukwahlulwa kwe-microphase kweemveliso.
Iinxalenye ze-amino ester ezenziwe zii-isocyanates ze-aliphatic zihambelana kakuhle neenxalenye ezithambileyo, nto leyo ebangela ukuba iinxalenye eziqinileyo zinyibilike kwiinxalenye ezithambileyo, nto leyo enciphisa inqanaba lokwahlulwa kwe-microphase. Iinxalenye ze-amino ester ezenziwe zii-isocyanates ezinuka kamnandi azihambelani kakuhle neenxalenye ezithambileyo, ngelixa inqanaba lokwahlulwa kwe-microphase liphezulu. I-polyurethane ye-Polyolefin inesakhiwo sokwahlulwa kwe-microphase esiphantse saphelela ngenxa yokuba icandelo elithambileyo alenzi iibhondi ze-hydrogen kwaye iibhondi ze-hydrogen zinokwenzeka kuphela kwicandelo eliqinileyo.
Isiphumo sokubopha i-hydrogen kwindawo yokuthamba kwee-elastomers sibalulekile. Nangona ii-polyethers kunye nee-carbonyls kwinxalenye ethambileyo zinokwenza inani elikhulu leebhondi ze-hydrogen kunye ne-NH kwinxalenye eqinileyo, ikwanyusa ubushushu bokuthamba kwee-elastomers. Kuqinisekisiwe ukuba iibhondi ze-hydrogen zisagcina i-40% kwi-200 ℃.
02 Ukubola kobushushu
Amaqela e-amino ester adlula kule nkqubo yokubola kubushushu obuphezulu:
- RNHCOOR – RNC0 HO-R
- RNHCOOR – RNH2 CO2 ene
- RNHCOOR – RNHR CO2 ene
Kukho iindlela ezintathu eziphambili zokubola kobushushu bezinto ezisekwe kwi-polyurethane:
① Ukwenza ii-isocyanates kunye nee-polyols zokuqala;
② α— I-oxygen bond kwisiseko se-CH2 iyaqhekeka ize idibane ne-hydrogen bond enye kwi-CH2 yesibini ukuze yenze ii-amino acids kunye nee-alkenes. Ii-amino acids ziyabola zibe yi-amine enye ephambili kunye ne-carbon dioxide:
③ Ifomu 1 ye-amine yesibini kunye ne-carbon dioxide.
Ukubola kobushushu besakhiwo 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 ℃.
Uzinzo lobushushu lwee-amino acid esters lunxulumene neentlobo zezinto zokuqala ezifana nee-isocyanates kunye nee-polyols. Ii-isocyanates ze-Aliphatic ziphezulu kunee-aromatic isocyanates, ngelixa ii-fatty alcohols ziphezulu kunee-aromatic alcohols. Nangona kunjalo, uncwadi lubika ukuba ubushushu bokubola kobushushu bee-aliphatic amino acid esters buphakathi kwe-160-180 ℃, kwaye obo be-aromatic amino acid esters buphakathi kwe-180-200 ℃, nto leyo engahambelaniyo nedatha engentla. Isizathu sinokuhambelana nendlela yokuvavanya.
Enyanisweni, i-aliphatic CHDI (1,4-cyclohexane diisocyanate) kunye ne-HDI (hexamethylene diisocyanate) zinokumelana nobushushu okungcono kune-aromatic MDI kunye ne-TDI esetyenziswa rhoqo. Ingakumbi i-trans CHDI enesakhiwo esilinganayo iye yabonwa njengeyona isocyanate imelana nobushushu kakhulu. Ii-polyurethane elastomers ezenziwe ngayo zinokumelana nobushushu okuhle, ukumelana ne-hydrolysis egqwesileyo, ubushushu obuphezulu bokuthambisa, ubushushu obuphantsi bokutshintsha kweglasi, i-hysteresis ephantsi yobushushu, kunye nokumelana ne-UV ephezulu.
Ukongeza kwiqela le-amino ester, ii-polyurethane elastomers nazo zinamaqela asebenzayo afana ne-urea formate, i-biuret, i-urea, njl. La maqela anokubola ngobushushu xa amaqondo obushushu aphezulu:
I-NHCONCOO – (i-aliphatic urea formate), 85-105 ℃;
- NHCONCOO – (i-aromatic urea formate), kubushushu obuyi-1-120 ℃;
- NHCONCONH – (aliphatic biuret), kubushushu obuqala kwi-10 ° C ukuya kwi-110 ° C;
I-NHCONCONH – (i-biuret enuka kamnandi), 115-125 ℃;
I-NHCONH – (i-aliphatic urea), 140-180 ℃;
- NHCONH – (i-urea enuka kamnandi), 160-200 ℃;
Isangqa se-Isocyanurate>270 ℃.
Ubushushu bokubola kobushushu be-biuret kunye ne-urea based formate buphantsi kakhulu kune-aminoformate kunye ne-urea, ngelixa i-isocyanurate inozinzo oluhle kakhulu lobushushu. Kwimveliso yee-elastomers, ii-isocyanates ezigqithisileyo zinokusabela ngakumbi kwi-aminoformate kunye ne-urea ezenziweyo ukuze zenze izakhiwo ezidityaniswe ne-urea based formate kunye ne-biuret cross-linked. Nangona zinokuphucula iipropati zoomatshini ze-elastomers, azizinzanga kakhulu ekufudumaleni.
Ukunciphisa amaqela angazinzile kubushushu afana ne-biuret kunye ne-urea formate kwi-elastomers, kuyimfuneko ukuqwalasela umlinganiselo wezinto eziluhlaza kunye nenkqubo yemveliso. Umlinganiselo we-isocyanate ogqithisileyo kufuneka usetyenziswe, kwaye ezinye iindlela kufuneka zisetyenziswe kangangoko kunokwenzeka ukuze kuqala kwenziwe amaringi e-isocyanate angaphelelanga kwizinto eziluhlaza (ikakhulu i-isocyanates, i-polyols, kunye nee-chain extenders), uze uzifake kwi-elastomer ngokweenkqubo eziqhelekileyo. Le ibe yindlela esetyenziswa kakhulu ukuvelisa ii-polyurethane elastomers ezimelana nobushushu kunye nezingatshiyo.
03 I-Hydrolysis kunye ne-thermal oxidation
Ii-elastomer ze-polyurethane zinobunzima bokubola kobushushu kwiindawo zazo eziqinileyo kunye notshintsho lweekhemikhali oluhambelanayo kwiindawo zazo ezithambileyo kumaqondo obushushu aphezulu. Ii-elastomer ze-polyester azinawo amandla okumelana namanzi kwaye zinotyekelo olunzima lokusebenzisa i-hydrolyze kumaqondo obushushu aphezulu. Ubomi benkonzo ye-polyester/TDI/diamine bunokufikelela kwiinyanga ezi-4-5 kwi-50 ℃, iiveki ezimbini kuphela kwi-70 ℃, kwaye iintsuku ezimbalwa kuphela ngaphezulu kwe-100 ℃. Iibhondi ze-Ester zinokubola zibe zii-asidi kunye nee-alcohols ezifanelekileyo xa zivezwe emanzini ashushu kunye nomphunga, kwaye amaqela e-urea kunye ne-amino ester kwi-elastomers nawo anokungenelwa ziimpendulo ze-hydrolysis:
RCOOR H20- → RCOOH HOR
Utywala be-Ester
Inye i-RNHCONHR enye i-H20- → i-RXHCOOH H2NR -
I-Ureamide
Inye i-RNHCOOR-H20- → i-RNCOOH HOR -
I-Amino formate ester I-Amino formate alcohol
Ii-elastomers ezisekelwe kwi-polyether azinawo uzinzo olubi kwi-thermal oxidation, kwaye ii-elastomers ezisekelwe kwi-ether α- I-hydrogen ekwi-athomu yekhabhoni inyibilikiswa lula, yenze i-hydrogen peroxide. Emva kokuqhekeka nokuqhekeka okungakumbi, ivelisa ii-oxide radicals kunye nee-hydroxyl radicals, ezithi ekugqibeleni zibole zibe zii-formates okanye ii-aldehydes.
Iipolyester ezahlukeneyo azinampembelelo ingako ekumelaneni nobushushu kwee-elastomers, ngelixa iipolyether ezahlukeneyo zinempembelelo ethile. Xa kuthelekiswa ne-TDI-MOCA-PTMEG, i-TDI-MOCA-PTMEG inomlinganiselo wokugcina amandla okutsalwa angama-44% kunye nama-60% ngokulandelelanayo xa ikhula kwi-121 ℃ kangangeentsuku ezi-7, kwaye le yokugqibela ingcono kakhulu kuneyokuqala. Isizathu sisenokuba kukuba iimolekyuli zePPG zinemixokelelwane enamasebe, engalungelaniyo nokulungelelaniswa rhoqo kweemolekyuli ze-elastic kwaye inciphisa ukumelana nobushushu bomzimba we-elastic. Umyalelo wozinzo lobushushu lweepolyethers ngu: PTMEG>PEG>PPG.
Amanye amaqela asebenzayo kwi-polyurethane elastomers, njenge-urea kunye ne-carbamate, nawo afumana ii-oxidation kunye ne-hydrolysis reactions. Nangona kunjalo, iqela le-ether lelona lifumaneka lula kwi-oxidation, ngelixa iqela le-ester lelona lifumaneka lula kwi-hydrolyzed. Ulandelelwano lokumelana kwabo ne-antioxidant kunye ne-hydrolysis lulandelayo:
Umsebenzi we-antioxidant: ii-esters>urea>carbamate>ether;
Ukumelana ne-hydrolysis: i-ester
Ukuphucula ukumelana nokuxinana kwe-polyether polyurethane kunye nokumelana ne-hydrolysis ye-polyester polyurethane, kongezwa nezinye izongezo, njengokongeza i-1% ye-phenolic antioxidant Irganox1010 kwi-PTMEG polyether elastomer. Amandla okuxinana kwale elastomer anokwandiswa amaxesha ama-3-5 xa kuthelekiswa nokungabikho kwe-antioxidants (iziphumo zovavanyo emva kokuguga kwi-1500C iiyure ezili-168). Kodwa ayizizo zonke ii-antioxidant ezinefuthe kwi-polyurethane elastomers, yi-phenolic 1rganox 1010 kunye ne-TopanOl051 kuphela (i-phenolic antioxidant, i-hindraid amine light stabilizer, i-benzotriazole complex) ezineziphumo ezibalulekileyo, kwaye eyokuqala yeyona ilungileyo, mhlawumbi kuba ii-phenolic antioxidants zihambelana kakuhle nee-elastomers. Nangona kunjalo, ngenxa yendima ebalulekileyo yamaqela e-phenolic hydroxyl kwindlela yokuzinzisa ii-antioxidants ze-phenolic, ukuze kuthintelwe ukusabela kunye "nokungaphumeleli" kweli qela le-phenolic hydroxyl elinamaqela e-isocyanate kwinkqubo, umlinganiselo we-isocyanates kwi-polyols akufuneki ube mkhulu kakhulu, kwaye ii-antioxidants kufuneka zongezwe kwi-prepolymers kunye ne-chain extenders. Ukuba zongezwa ngexesha lokuveliswa kwee-prepolymers, ziya kuyichaphazela kakhulu impembelelo yokuzinzisa.
Izithako ezisetyenziselwa ukuthintela i-hydrolysis ye-polyester polyurethane elastomers ikakhulu zii-carbodiimide compounds, ezisabela kunye nee-carboxylic acids eziveliswa yi-ester hydrolysis kwiimolekyuli ze-polyurethane elastomer ukuvelisa i-acyl urea derivatives, nto leyo ethintela i-hydrolysis engaphezulu. Ukongezwa kwe-carbodiimide kwi-mass fraction ye-2% ukuya kwi-5% kunokunyusa uzinzo lwamanzi lwe-polyurethane ngamaxesha ama-2-4. Ukongeza, i-tert butyl catechol, i-hexamethylenetetramine, i-azodicarbonamide, njl.njl. nazo zinemiphumo ethile yokulwa ne-hydrolysis.
04 Iimpawu eziphambili zokusebenza
Ii-elastomers zePolyurethane zii-copolymers eziqhelekileyo ze-multi block, ezinee-molecular chain ezenziwe ngamacandelo aguquguqukayo ane-glass transition temperature ephantsi kune-room temperature kunye nee-rigid segments ezine-glass transition temperature ephezulu kune-room temperature. Phakathi kwazo, ii-oligomeric polyols zenza amacandelo aguquguqukayo, ngelixa ii-diisocyanates kunye nee-small molecule chain extenders zenza amacandelo aqinileyo. Ulwakhiwo olufakwe ngaphakathi lwamacandelo aguquguqukayo naqinileyo lwe-chain lumisela ukusebenza kwawo okwahlukileyo:
(1) Uluhlu lobunzima berabha eqhelekileyo luhlala luphakathi kweShaoer A20-A90, ngelixa uluhlu lobunzima beplastiki lumalunga neShaoer A95 Shaoer D100. Ii-elastomers zePolyurethane zinokufikelela ezantsi njengeShaoer A10 kwaye zifikelele eShaoer D85, ngaphandle kwesidingo soncedo lokuzalisa;
(2) Amandla aphezulu kunye nokuthamba kusenokugcinwa ngaphakathi koluhlu olubanzi lobunzima;
(3) Ukumelana nokuguguleka okugqwesileyo, okuphindwe kabini ukuya kwishumi kunerabha yendalo;
(4) Ukumelana kakuhle namanzi, ioyile, kunye neekhemikhali;
(5) Ukumelana nempembelelo ephezulu, ukumelana nokudinwa, kunye nokumelana nokungcangcazela, okufanelekileyo kwizicelo zokugoba ezisebenzisa amaxesha amaninzi;
(6) Ukumelana okuhle nobushushu obuphantsi, kunye nokungaqini kobushushu obuphantsi ngaphantsi kwe -30 ℃ okanye -70 ℃;
(7) Isebenza kakuhle kakhulu ekugqumeni, kwaye ngenxa yokuba iphantsi kakhulu ekufudumaleni, inefuthe elingcono ekugqumeni xa ithelekiswa nerabha kunye neplastiki;
(8) Iipropati ezilungileyo zokuhambelana kwezinto eziphilayo kunye ne-anticoagulant;
(9) Ubushushu obugqwesileyo bombane, ukumelana nokungunda, kunye nozinzo lwe-UV.
Ii-elastomers ze-polyurethane zinokwenziwa kusetyenziswa iinkqubo ezifanayo nezerabha eqhelekileyo, ezifana nokufakelwa kweplastiki, ukuxuba, kunye nokufakelwa kwe-vulcanization. Zingabunjwa ngendlela yerabha engamanzi ngokuthulula, ukubumba nge-centrifugal, okanye ukutshiza. Zingenziwa zibe zizinto ezinamaqhekeza kwaye zenziwe kusetyenziswa i-injection, extrusion, rolling, blow molding, kunye nezinye iinkqubo. Ngale ndlela, ayiphuculi nje kuphela ukusebenza kakuhle, kodwa ikwaphucula ukuchaneka kobukhulu kunye nembonakalo yemveliso.
Ixesha lokuthumela: Disemba-05-2023