Ko te mea e kiia neipolyurethaneKo te kupu "polyurethane" te whakarāpopototanga o te polyurethane, e hangaia ana mā te tauhohenga o ngā polyisocyanates me ngā polyols, ā, he maha ngā rōpū amino ester e tāruaruatia ana (- NH-CO-O -) i runga i te mekameka ngota. I roto i ngā kapia polyurethane kua hangaia, hei tāpiri atu ki te rōpū amino ester, kei reira anō ngā rōpū pērā i te urea me te biuret. Nō ngā ngota mekameka roa ngā polyols me ngā rōpū hydroxyl i te mutunga, e kiia ana ko "ngā wāhanga mekameka ngohengohe", ko ngā polyisocyanates ia e kiia ana ko "ngā wāhanga mekameka mārō".
I roto i ngā kapia polyurethane i hangaia e ngā wāhanga mekameka ngohengohe me ngā wāhanga mekameka mārō, he iti noa iho te ōrau he esters waikawa amino, nō reira kāore pea i te tika kia kiia he polyurethane. I te whānui, he tāpiringa o te isocyanate te polyurethane.
Ka tauhohe ngā momo isocyanate rerekē ki ngā pūhui polyhydroxy hei whakaputa i ngā hanganga polyurethane rerekē, ā, ka puta he rauemi polymer me ngā āhuatanga rerekē, pērā i te kirihou, te rapa, ngā paninga, ngā muka, ngā piripiri, me ētahi atu. Rapa polyurethane
Nō tētahi momo rapa motuhake te rapa polyurethane, e hangaia ana mā te tauhohenga o te polyether, te polyester rānei ki te isocyanate. He maha ngā momo nā runga i ngā momo rauemi mata, ngā āhuatanga tauhohenga, me ngā tikanga honohono. Mai i te tirohanga hanganga matū, he momo polyester me te polyether, ā, mai i te tirohanga tikanga tukatuka, e toru ngā momo: te momo whakaranu, te momo maka, me te momo thermoplastic.
Ko te tikanga, ka hangaia te rapa polyurethane hangai mā te tauhohe i te polyester, te polyether rānei ki te diisocyanate hei hanga i te prepolymer taumaha ngota iti, kātahi ka tukuna ki te tauhohenga toronga mekameka hei whakaputa i te polymer taumaha ngota teitei. Kātahi ka tāpirihia ngā kaihoko hononga e tika ana, ka whakamahanahia kia mārō, ka huri hei rapa whakamomona. Ka kiia tēnei tikanga ko te prepolymerization, ko te tikanga rua-taahiraa rānei.
Ka taea hoki te whakamahi i tētahi tikanga kotahi-taahiraa – te whakaranu tika i te polyester, te polyether rārangi rānei me ngā diisocyanates, ngā whakaroa mekameka, me ngā kaihoko hononga whakawhiti hei tīmata i tētahi tauhohenga me te whakaputa rapa polyurethane.
Mā te wāhanga-A i roto i ngā ngota TPU ka ngāwari te huri i ngā mekameka macromolecular, ka pai te ngāwari o te rapa polyurethane, ka whakaiti i te pūwāhi whakangawari me te pūwāhi whakawhiti tuarua o te polymer, ka whakaiti i tōna pakeketanga me tōna kaha ā-pūmanawa. Ka herea e te wāhanga-B te hurihanga o ngā mekameka macromolecular, ka piki ake te pūwāhi whakangawari me te pūwāhi whakawhiti tuarua o te polymer, ka piki ake te pakeketanga me te kaha ā-pūmanawa, ka heke iho te ngāwaritanga. Mā te whakarerekē i te ōwehenga molar i waenga i a A me B, ka taea te whakaputa i ngā TPU me ngā āhuatanga ā-pūmanawa rerekē. Me whakaaro te hanganga hononga-whiti o te TPU ki te hononga-whiti tuatahi, me te hononga-whiti tuarua i hangaia e ngā hononga hauwai i waenga i ngā ngota. He rerekē te hononga-whiti tuatahi o te polyurethane i te hanganga whakamomona o te rapa hydroxyl. Ko tōna rōpū amino ester, te rōpū biuret, te rōpū urea formate me ētahi atu rōpū mahi kua whakaritea ki roto i te wāhanga mekameka mārō me te tawhiti, ka hua ake he hanganga whatunga rapa rite tonu, he ātete kakahu pai me ētahi atu āhuatanga pai. Tuarua, nā te mea he maha ngā rōpū mahi tino piripono pērā i te urea, i te carbamate rānei i roto i te rapa polyurethane, he kaha te hononga hauwai i hangaia i waenga i ngā mekameka ngota, ā, he pānga nui anō hoki ngā hononga whakawhiti tuarua i hangaia e ngā hononga hauwai ki ngā āhuatanga o te rapa polyurethane. Mā te hononga whakawhiti tuarua ka taea e te rapa polyurethane te whai i ngā āhuatanga o ngā elastomers thermosetting i tetahi taha, ā, i tetahi atu taha, kāore tēnei hononga whakawhiti i te tino hononga whakawhiti, ka waiho hei hononga whakawhiti mariko. Ko te āhua hononga whakawhiti e whakawhirinaki ana ki te pāmahana. I te pikinga o te pāmahana, ka ngoikore haere tēnei hononga whakawhiti, ka ngaro. He āhua rere te polymer, ā, ka taea te tukatuka thermoplastic. Ina heke te pāmahana, ka ora haere tēnei hononga whakawhiti, ka hanga anō. Mā te tāpiri i tētahi iti o te whakakī ka whakanui ake i te tawhiti i waenga i ngā ngota, ka ngoikore te kaha ki te hanga hononga hauwai i waenga i ngā ngota, ā, ka heke te kaha. Kua whakaatuhia e te rangahau ko te raupapa pumau o ngā rōpū mahi rerekē i roto i te rapa polyurethane mai i te teitei ki te iti ko: ester, ether, urea, carbamate, me te biuret. I te wā e pakeke haere ana te rapa polyurethane, ko te taahiraa tuatahi ko te motu i ngā hononga whakawhiti i waenga i te biuret me te urea, ā, muri iho ko te motu i ngā hononga carbamate me te urea, arā, ko te motu o te mekameka matua.
01 Te Whakangawari
Pērā i te nuinga o ngā rauemi pūmua, ka ngawari ngā elastomer polyurethane i ngā pāmahana teitei, ā, ka huri mai i te āhua pīngore ki te āhua rere matotoru, ka tere te heke o te kaha ā-ringa. Mai i te tirohanga matū, ko te pāmahana whakangawari o te pīngore e whakawhirinaki ana ki ngā āhuatanga pēnei i tōna hanganga matū, te taumaha ngota whanaunga, me te mātotoru hononga.
I te nuinga o te wā, ko te whakanui ake i te taumaha ngota ngota whanaunga, te whakanui ake i te pakari o te wāhanga mārō (pēnei i te whakauru i te mowhiti benzene ki roto i te ngota) me te ihirangi o te wāhanga mārō, me te whakanui ake i te mātotoru hononga whakawhiti he mea pai katoa mō te whakanui ake i te pāmahana whakangawari. Mō ngā elastomers thermoplastic, he rārangi te hanganga ngota ngota, ā, ka piki ake hoki te pāmahana whakangawari o te elastomer ina whakanuia te taumaha ngota ngota whanaunga.
Mō ngā elastomers polyurethane honohono-whiti, he nui ake te pānga o te mātotoru honohono-whiti i te taumaha ngota ngota whanaunga. Nō reira, i te wā e hanga ana i ngā elastomers, mā te whakanui ake i te mahi a ngā isocyanates, polyols rānei ka taea te hanga i tētahi hanganga honohono-matū whatunga pumau i roto i ētahi o ngā ngota rapa, te whakamahi rānei i ngā ōwehenga isocyanate nui rawa hei hanga i tētahi hanganga honohono-whiti isocyanate pumau i roto i te tinana rapa he huarahi kaha ki te whakapai ake i te ātete wera, te ātete whakarewa, me te kaha miihini o te elastomer.
Ina whakamahia te PPDI (p-phenyldiisocyanate) hei rauemi mata, nā te hononga tika o ngā rōpū isocyanate e rua ki te mowhiti benzene, he nui ake te ihirangi mowhiti benzene o te wāhanga mārō kua hangaia, ka whakapai ake i te pakari o te wāhanga mārō, ā, ka whakanui ake i te ātete wera o te elastomer.
Mai i te tirohanga ā-tinana, ko te pāmahana whakangawari o ngā elastomers e whakawhirinaki ana ki te nui o te wehenga ā-moroiti. E ai ki ngā pūrongo, he tino iti te pāmahana whakangawari o ngā elastomers kāore e wehea ā-moroiti, me te pāmahana tukatuka o te 70 ℃ anake, ko ngā elastomers ia e wehea ana ā-moroiti ka eke ki te 130-150 ℃. Nō reira, ko te whakanui ake i te nui o te wehenga ā-moroiti i roto i ngā elastomers tētahi o ngā tikanga whai hua hei whakapai ake i tō rātou ātete wera.
Ka taea te whakapai ake i te nui o te wehenga ā-moroiti o ngā elastomers mā te whakarerekē i te tohatoha taumaha ngota ngota whanaunga o ngā wāhanga mekameka me te ihirangi o ngā wāhanga mekameka pakari, ā, mā reira ka whakarei ake i tō rātou ātete wera. E whakapono ana te nuinga o ngā kairangahau ko te take o te wehenga ā-moroiti i roto i te polyurethane ko te kore hototahitanga o te pāmahana i waenga i ngā wāhanga ngohengohe me ngā wāhanga pakeke. He pānga nui tō te momo whakaroa mekameka, te wāhanga pakeke me ōna ihirangi, te momo wāhanga ngohengohe, me te hononga hauwai ki a ia.
Ki te whakatauritea ki ngā whakaroa mekameka diol, ko ngā whakaroa mekameka diamine pēnei i te MOCA (3,3-dichloro-4,4-diaminodiphenylmethane) me te DCB (3,3-dichloro-biphenylenediamine) ka hanga i ngā rōpū amino ester polar ake i roto i ngā elastomers, ā, ka taea te hanga hononga hauwai ake i waenga i ngā wāhanga pakeke, ka whakanui ake i te taunekeneke i waenga i ngā wāhanga pakeke me te whakapai ake i te taumata o te wehenga microphase i roto i ngā elastomers; He pai ngā whakaroa mekameka kakara ōrite pēnei i te p, p-dihydroquinone, me te hydroquinone mō te whakatikatika me te tākai piri o ngā wāhanga pakeke, ā, ka whakapai ake i te wehenga microphase o ngā hua.
He pai te hototahitanga o ngā wāhanga amino ester i hangaia e ngā isocyanate aliphatic ki ngā wāhanga ngohengohe, ka hua ake he nui ake ngā wāhanga mārō e memeha ana i roto i ngā wāhanga ngohengohe, ka whakaiti i te nui o te wehenga ā-mokoro. He ngoikore te hototahitanga o ngā wāhanga amino ester i hangaia e ngā isocyanate kakara ki ngā wāhanga ngohengohe, engari he teitei ake te nui o te wehenga ā-mokoro. He tata tonu te hanganga wehenga ā-mokoro o te polyurethane polyolefin nā te mea kāore te wāhanga ngohengohe e hanga hononga hauwai, ā, ka taea anake te puta ngā hononga hauwai i roto i te wāhanga mārō.
He mea nui anō hoki te pānga o te here hauwai ki te pūwāhi whakangawari o ngā elastomers. Ahakoa ka taea e ngā polyether me ngā carbonyl i roto i te wāhanga ngohengohe te hanga i te maha o ngā here hauwai me te NH i roto i te wāhanga mārō, ka piki ake anō hoki te pāmahana whakangawari o ngā elastomers. Kua whakaūtia kei te mau tonu ngā here hauwai ki te 40% i te 200 ℃.
02 Te pirau wera
Ka pāngia ngā rōpū amino ester e ngā pāmahana tiketike e whai ake nei:
- RNHCOOR – RNC0 HO-R
- RNHCOOR – RNH2 CO2 ene
- RNHCOOR – RNHR CO2 ene
E toru ngā momo matua o te pirau wera o ngā rauemi polyurethane:
① Te hanga i ngā isocyanates me ngā polyols taketake;
② α— Ka motu te here hāora i runga i te turanga CH2, ā, ka hono atu ki te here hauwai kotahi i runga i te tuarua o ngā CH2 hei hanga i ngā waikawa amino me ngā alkene. Ka pakaru ngā waikawa amino hei amine tuatahi kotahi me te hauhā waro:
③ Amene tuarua me te hauhā waro āhua 1.
Te wetewete wera o te hanganga carbamate:
Aryl NHCO Aryl,~120 ℃;
N-alkyl-NHCO-aryl,~180 ℃;
Aryl NHCO n-alkyl,~200 ℃;
N-alkyl-NHCO-n-alkyl,~250 ℃.
Ko te pumau wera o ngā waikawa amino esters e pā ana ki ngā momo rauemi tīmatanga pēnei i te isocyanates me te polyols. He teitei ake ngā isocyanates aliphatic i ngā isocyanates kakara, ko ngā waipiro ngako he teitei ake i ngā waipiro kakara. Heoi, e ai ki ngā tuhinga ko te pāmahana pirau wera o ngā waikawa amino esters aliphatic kei waenga i te 160-180 ℃, ā, ko ngā waikawa amino esters kakara kei waenga i te 180-200 ℃, he mea kāore e rite ki ngā raraunga o runga ake nei. Tērā pea ko te take e pā ana ki te tikanga whakamātautau.
Ina hoki, he pai ake te ātete wera o te CHDI aliphatic (1,4-cyclohexane diisocyanate) me te HDI (hexamethylene diisocyanate) i te MDI kakara me te TDI e whakamahia whānuitia ana. Ina koa ko te CHDI trans me te hanganga ōrite kua mōhiotia ko te isocyanate tino ātete wera. He pai te tukatuka o ngā elastomers polyurethane i hangaia mai i a ia, he ātete pai ki te waikura, he pāmahana whakangawari teitei, he pāmahana whakawhiti karāhe iti, he hysteresis wera iti, me te ātete UV teitei.
Haunga te rōpū amino ester, kei roto anō i ngā elastomers polyurethane ētahi atu rōpū mahi pērā i te urea formate, te biuret, te urea, me ētahi atu. Ka taea e ēnei rōpū te pirau wera i ngā pāmahana teitei:
NHCONCOO – (whakapūtanga urea aliphatic), 85-105 ℃;
- NHCONCOO – (te urea formate kakara), i te awhe pāmahana 1-120 ℃;
- NHCONCONH – (biuret aliphatic), i te pāmahana mai i te 10 ° C ki te 110 ° C;
NHCONCONH – (biuret kakara), 115-125 ℃;
NHCONH – (ūrea āripātika), 140-180 ℃;
- NHCONH – (urea kakara), 160-200 ℃;
Mowhiti isocyanurate>270 ℃.
He iti iho te pāmahana pirau wera o te formate biuret me te urea i tērā o te aminoformate me te urea, ko te isocyanurate te mea tino pumau i te wera. I roto i te hanga elastomers, ka taea e ngā isocyanates nui rawa te tauhohe atu ki te aminoformate me te urea kua hangaia hei hanga i ngā hanganga formate me te biuret kua honoa. Ahakoa ka taea e rātou te whakapai ake i ngā āhuatanga miihini o ngā elastomers, he tino koretake ki te wera.
Hei whakaiti i ngā rōpū kore pumau o te wera pērā i te biuret me te urea formate i roto i ngā elastomers, me whai whakaaro ki te ōwehenga o ngā rauemi mata me te tukanga whakaputa. Me whakamahi i ngā ōwehenga isocyanate nui rawa atu, ā, me whakamahi i ētahi atu tikanga kia taea ai te hanga tuatahi i ngā mowhiti isocyanate wāhanga i roto i ngā rauemi mata (ko te nuinga he isocyanates, polyols, me ngā whakaroa mekameka), kātahi ka whakaurua ki roto i te elastomer kia rite ki ngā tukanga noa. Kua waiho tēnei hei tikanga e whakamahia whānuitia ana mō te whakaputa i ngā elastomers polyurethane ātete wera me te ātete mura.
03 Te waikura me te waikura wera
He ngāwari ngā elastomer polyurethane ki te pirau wera i roto i ō rātou wāhanga pakeke, me ngā huringa matū e rite ana ki ō rātou wāhanga ngohengohe i ngā pāmahana teitei. He ngoikore te ātete wai o ngā elastomer polyester, ā, he kaha ake te āhua ki te waikura i ngā pāmahana teitei. Ka taea e te roanga mahi o te polyester/TDI/diamine te eke ki te 4-5 marama i te 50 ℃, e rua wiki noa iho i te 70 ℃, ā, he torutoru noa ngā rā i runga ake i te 100 ℃. Ka taea e ngā hononga ester te pirau ki ngā waikawa me ngā waipiro e rite ana ina pāngia e te wai wera me te mamaoa, ā, ka taea hoki e ngā rōpū urea me te amino ester i roto i ngā elastomer te pāngia e ngā tauhohenga waikura:
RCOOR H20- → RCOOH HOR
Waipiro Ester
Kotahi RNHCONHR kotahi H20- → RXHCOOH H2NR -
Ureamide
Kotahi RNHCOOR-H20- → RNCOOH HOR -
Amino formate ester Waipiro amino formate
He ngoikore te pumau o te waikura wera o ngā elastomers e hangai ana ki te polyether, ā, ka ngāwari te waikura o ngā elastomers e hangai ana ki te ether α- i te hauwai i runga i te ngota waro, ka hanga he hauwai peroxide. I muri i te wetewete me te tapahi, ka puta he rauropi waikura me ngā rauropi hydroxyl, ka wetewete hei formates, hei aldehydes rānei.
He iti noa te pānga o ngā polyester rerekē ki te ātete wera o ngā elastomers, engari he pānga anō tō ngā polyether rerekē. Ki te whakatauritea ki te TDI-MOCA-PTMEG, ko te tere pupuri kaha kume o te TDI-MOCA-PTMEG he 44% me te 60% ia ina pakekehia i te 121 ℃ mō ngā rā e 7, ā, he pai ake te mea whakamutunga i te mea tuatahi. Ko te take pea he mekameka peka ngā ngota PPG, kāore e pai ki te whakaritenga auau o ngā ngota rapa, ā, ka whakaiti i te ātete wera o te tinana rapa. Ko te raupapa pumau wera o ngā polyether ko: PTMEG>PEG>PPG.
Ka pāngia hoki ētahi atu rōpū mahi i roto i ngā elastomers polyurethane, pērā i te urea me te carbamate, e ngā tauhohenga waikura me te waikura. Heoi, ko te rōpū ether te mea tino ngāwari ki te waikura, ko te rōpū ester ia te mea tino ngāwari ki te waikura. Ko te raupapa o tō rātou ātete antioxidant me te waikura ko:
Ngā mahi ārai-ātete: ngā ester>urea>carbamate>ether;
Ātete ki te waikura: ester
Hei whakapai ake i te ātete waikura o te polyether polyurethane me te ātete hydrolysis o te polyester polyurethane, ka tāpirihia hoki ngā tāpiringa, pērā i te tāpiri i te 1% phenolic antioxidant Irganox1010 ki te PTMEG polyether elastomer. Ka taea te whakanui ake i te kaha kume o tēnei elastomer mā te 3-5 ngā wā ki te whakataurite ki te kore he antioxidants (ngā hua whakamātautau i muri i te pakeketanga i te 1500C mō te 168 hāora). Engari kāore e pā ana ngā antioxidants katoa ki ngā elastomers polyurethane, ko te phenolic 1rganox 1010 me te TopanOl051 anake (phenolic antioxidant, hindered amine light stabilizer, benzotriazole complex) he pānga nui, ā, ko te mea tuatahi te mea pai rawa atu, nā te mea pea he pai te hototahi o ngā antioxidants phenolic ki ngā elastomers. Heoi, nā te mea he mea nui te mahi a ngā rōpū phenolic hydroxyl i roto i te tikanga whakapūmau o ngā antioxidants phenolic, kia kore ai e tauhohe me te "korenga" o tēnei rōpū phenolic hydroxyl me ngā rōpū isocyanate i roto i te pūnaha, kaua e nui rawa te ōwehenga o ngā isocyanates ki ngā polyols, ā, me tāpiri ngā antioxidants ki ngā prepolymers me ngā whakaroa mekameka. Mēnā ka tāpirihia i te wā e hangaia ana ngā prepolymers, ka nui te pānga ki te pānga whakapūmau.
Ko ngā tāpiringa e whakamahia ana hei ārai i te waikura o ngā elastomers polyurethane polyester he matū carbodiimide te nuinga, e tauhohe ana ki ngā waikawa carboxylic i hangaia e te waikura ester i roto i ngā ngota elastomer polyurethane hei whakaputa i ngā hua acyl urea, hei ārai i te waikura anō. Mā te tāpiri o te carbodiimide i te wāhanga papatipu o te 2% ki te 5% ka taea te whakanui ake i te pumau wai o te polyurethane mā te 2-4 ngā wā. Hei tāpiri, he pānga ārai waikura anō hoki tō tert butyl catechol, hexamethylenetetramine, azodicarbonamide, me ētahi atu.
04 Ngā āhuatanga mahi matua
Ko ngā elastomer polyurethane he copolymer poraka maha noa iho, me ngā mekameka ngota i hangaia mai i ngā wāhanga ngāwari me te pāmahana whakawhiti karāhe i raro iho i te pāmahana rūma me ngā wāhanga pakari me te pāmahana whakawhiti karāhe teitei ake i te pāmahana rūma. I roto i ēnei, ka hangaia e ngā polyol oligomeric ngā wāhanga ngāwari, ko ngā diisocyanate me ngā kaiwhakaroa mekameka ngota iti ka hangaia ngā wāhanga pakari. Ko te hanganga whakauru o ngā wāhanga mekameka ngāwari me te pakari e whakatau ana i tā rātou mahi ahurei:
(1) Ko te awhe pakeke o te rapa noa kei waenganui i te Shaoer A20-A90, ko te awhe pakeke o te kirihou kei waenganui i te Shaoer A95 Shaoer D100. Ka taea e ngā elastomers polyurethane te tae ki te iti rawa o te Shaoer A10 me te teitei rawa o te Shaoer D85, me te kore e hiahiatia he āwhina whakakī;
(2) Ka taea tonu te pupuri i te kaha me te ngāwari o te hanga i roto i te whānuitanga o te pakeketanga;
(3) He ātete pai rawa atu ki te kakahu, e 2-10 ngā wā i tō te rapa maori;
(4) He ātete tino pai ki te wai, te hinu, me ngā matū;
(5) He ātete nui ki te pānga, ki te ngenge, ki te wiri hoki, he pai mō ngā tono piko auau teitei;
(6) He ātete pai ki te pāmahana iti, me te pakarukaru o te pāmahana iti i raro i te -30 ℃, i te -70 ℃ rānei;
(7) He tino pai te mahi whakamarumaru, ā, nā te iti o te kawe wera, he pai ake te pānga whakamarumaru ki te whakataurite ki te rapa me te kirihou;
(8) He pai te hototahitanga koiora me ngā āhuatanga ārai toto;
(9) He tino pai te ārai hiko, te ātete ki te pokepokea ai, me te pumau ki te hihi UV.
Ka taea te hanga i ngā elastomer polyurethane mā te whakamahi i ngā tukanga ōrite ki te rapa noa, pērā i te whakakirikiri, te whakaranu, me te whakamomona. Ka taea hoki te whakakōpikopiko i te āhua o te rapa wai mā te ringihanga, te whakakōpikopiko, te rehu rānei. Ka taea hoki te hanga hei rauemi kirikiri, ā, mā te werohanga, te whakaputa, te hurihuri, te whakakōpikopiko pupuhi, me ētahi atu tukanga. Mā tēnei, ehara i te mea ka whakapai ake i te pai o te mahi anake, engari ka whakapai ake hoki i te tika o te āhua me te āhua o te hua.
Wā tuku: Hakihea-05-2023