Ihe a na-akpọpolyurethanebụ abbreviation nke polyurethane, nke a kpụrụ site mmeghachi omume nke polyisocyanates na polyols, na nwere ọtụtụ ugboro ugboro amino ester otu (- NH-CO-O -) na molekụla yinye.Na ezigbo resins polyurethane synthesized, na mgbakwunye na otu amino ester, e nwekwara otu dị ka urea na biuret.Polyols bụ nke ụmụ irighiri akwara ogologo nwere otu hydroxyl na njedebe, nke a na-akpọ "akụkụ dị nro", ebe a na-akpọ polyisocyanates "akụkụ siri ike".
N'ime resin polyurethane nke akụkụ dị nro na nke siri ike na-emepụta, ọ bụ naanị obere pasent bụ amino acid esters, n'ihi ya, ọ nwere ike ọ gaghị adị mma ịkpọ ha polyurethane.N'echiche sara mbara, polyurethane bụ ihe mgbakwunye nke isocyanate.
Ụdị dị iche iche nke isocyanates na-emeghachi omume na ogige polyhydroxy iji mepụta ụdị dị iche iche nke polyurethane, si otú ahụ na-enweta ihe ndị polymer nwere ihe dị iche iche, dị ka plastik, roba, mkpuchi, eriri, adhesives, wdg Polyurethane roba.
Polyurethane roba bụ nke ụdị roba pụrụ iche, nke a na-eme site na imeghachi polyether ma ọ bụ polyester na isocyanate.Enwere ọtụtụ ụdị n'ihi ụdị akụrụngwa dị iche iche, ọnọdụ mmeghachi omume, yana ụzọ njikọ.Site na usoro nhazi nke kemịkal, e nwere ụdị polyester na polyether, na site na usoro nhazi usoro, e nwere ụdị atọ: ụdị ngwakọta, ụdị nkedo, na ụdị thermoplastic.
Sịntetik polyurethane roba na-emekarị synthesized site na-emeghachi omume linear polyester ma ọ bụ polyether na diisocyanate na-etolite a ala molekụla arọ prepolymer, nke a na-doro n'okpuru yinye ndọtị mmeghachi omume n'ịwa elu molekul arọ polymer.Mgbe ahụ, a na-agbakwunye ihe ndị na-emekọrịta ihe kwesịrị ekwesị ma kpoo ọkụ iji gwọọ ya, ghọọ rọba vulcanized.A na-akpọ usoro a prepolymerization ma ọ bụ usoro nzọụkwụ abụọ.
Ọ ga-ekwe omume iji usoro otu nzọụkwụ - na-agwakọta polyester linear ma ọ bụ polyether ozugbo na diisocyanates, ndị na-eme ka agbụ ígwè, na ndị na-agafe agafe iji malite mmeghachi omume na ịmepụta polyurethane roba.
Akụkụ A na ụmụ irighiri ihe TPU na-eme ka agbụ macromolecular dị mfe ịtụgharị, na-enye roba polyurethane ezigbo elasticity, na-ebelata ebe nro na ntụgharị nke abụọ nke polymer, na ibelata ike ya na ike ọrụ.Akụkụ B ga-ejikọta ntụgharị nke ụdọ macromolecular, na-eme ka ebe dị nro na ntụgharị nke abụọ nke polymer na-abawanye, na-ebute mmụba nke ike na ike ọrụ, na mbelata nke ngbanwe.Site n'ịgbanwe nha molar n'etiti A na B, enwere ike ịmepụta TPU nwere ihe eji arụ ọrụ dị iche iche.Usoro njikọ njikọ nke TPU agaghị atụle naanị isi njikọ njikọ, kamakwa njikọ njikọ nke abụọ nke njikọ hydrogen na-etolite n'etiti ụmụ irighiri ihe.Njikọ njikọ njikọ nke bụ isi nke polyurethane dị iche na nhazi vulcanization nke roba hydroxyl.Ya amino ester otu, biuret otu, urea formate otu na ndị ọzọ na-arụ ọrụ dị iche iche na-ahaziri na a mgbe na spaced isiike yinye nkebi, dapụtara na a mgbe netwọk Ọdịdị nke roba, nke nwere magburu onwe eyi iguzogide na ndị ọzọ magburu onwe Njirimara.Nke abuo, n'ihi na ọnụnọ nke ọtụtụ ukwuu cohesive dị iche iche na-arụ ọrụ dị ka urea ma ọ bụ carbamate otu na polyurethane roba, hydrogen agbụ nke kpụrụ n'etiti molekụla agbụ nwere ike dị elu, na nke abụọ crosslinking bond guzobere site hydrogen bond nwekwara mmetụta dị ịrịba ama na Njirimara nke. roba polyurethane.Njikọ njikọ nke abụọ na-eme ka polyurethane rọba nwee njirimara nke thermosetting elastomer n'otu aka, na n'aka nke ọzọ, njikọ njikọ a abụghị njikọ n'ezie, na-eme ka ọ bụrụ njikọ njikọ.Ọnọdụ cross-link na-adabere na okpomọkụ.Ka okpomọkụ na-abawanye, njikọ a na-agafe agafe na-eji nwayọọ nwayọọ na-ebelata ma na-apụ n'anya.Na polima nwere ụfọdụ fluidity na ike ido n'okpuru thermoplastic nhazi.Mgbe okpomọkụ na-ebelata, njikọ a na-ejikọta ya na-eji nwayọọ nwayọọ na-agbake ma na-etolite ọzọ.Mgbakwunye nke obere ihe ndochi na-abawanye ohere dị n'etiti ụmụ irighiri ihe, na-ebelata ike ịmepụta njikọ hydrogen n'etiti ụmụ irighiri ihe, ma na-eduga n'ịbelata ike.Nnyocha egosiwo na usoro nkwụsi ike nke dị iche iche na-arụ ọrụ dị iche iche na roba polyurethane site na elu ruo ala bụ: ester, ether, urea, carbamate, na biuret.N'oge usoro ịka nká nke roba polyurethane, nzọụkwụ mbụ bụ nkwụsị nke njikọ njikọ n'etiti biuret na urea, na-esote nkwụsị nke carbamate na urea bond, ya bụ, isi ihe na-agbaji.
01 Ịdị nro
Polyurethane elastomers, dị ka ọtụtụ ihe ndị polymer, na-adị nro na okpomọkụ dị elu na mgbanwe site na ọnọdụ na-agbanwe agbanwe gaa na ọnọdụ viscous na-asọpụta, na-ebute mbelata ngwa ngwa na ike ọrụ.Site n'echiche kemịkalụ, okpomọkụ na-adị nro nke ngbanwe na-adabere na ihe ndị dị ka ihe mejupụtara kemịkalụ ya, ịdị arọ molekụla ikwu, na njupụta na-agafe agafe.
N'ikwu okwu n'ozuzu, ịbawanye ịdị arọ nke mkpụrụ ndụ ihe nketa, ịba ụba nke siri ike nke akụkụ siri ike (dịka iwebata mgbanaka benzene n'ime molekul) na ọdịnaya nke akụkụ siri ike, na ịba ụba njupụta nke crosslink na-aba uru maka ịba ụba okpomọkụ.Maka thermoplastic elastomer, ihe owuwu molekụla na-abụkarị nke ahịrị, na ọnọdụ okpomọkụ nke elastomer na-adị nro na-abawanye ma ọ bụrụ na ọ na-abawanye ịdị arọ nke molekul.
Maka polyurethane elastomers na-ejikọta ya, njupụta na-ejikọta ya na-enwe mmetụta dị ukwuu karịa ịdị arọ molecular ikwu.Ya mere, mgbe ị na-emepụta elastomers, ịba ụba ọrụ nke isocyanates ma ọ bụ polyols nwere ike ịmepụta usoro njikọ njikọ kemịkalụ netwọkụ na-ekpo ọkụ na ụfọdụ mkpụrụ ndụ na-agbanwe agbanwe, ma ọ bụ iji oke isocyanate oke na-etolite usoro njikọ njikọ isocyanate kwụsiri ike na ahụ na-agbanwe. ụzọ dị ike iji kwalite nguzogide okpomọkụ, ihe mgbaze, na ike igwe nke elastomer.
Mgbe a na-eji PPDI (p-phenyldiisocyanate) mee ihe dị ka ihe eji eme ihe, n'ihi njikọ kpọmkwem nke otu isocyanate abụọ na mgbanaka benzene, akụkụ ahụ siri ike a kpụrụ nwere ọdịnaya mgbanaka benzene dị elu, nke na-eme ka nkwụsi ike nke akụkụ siri ike dịkwuo mma ma si otú a na-eme ka ọ dịkwuo elu. na-eguzogide okpomọkụ nke elastomer.
Site n'echiche anụ ahụ, okpomọkụ na-adị nro nke elastomers na-adabere n'ogo nke nkewa microphase.Dị ka akụkọ si kwuo, okpomọkụ na-adị nro nke elastomers nke na-adịghị enweta nkewa microphase dị nnọọ ala, na-enwe okpomọkụ nhazi nke nanị ihe dịka 70 ℃, ebe elastomers na-enweta nkewa microphase nwere ike iru 130-150 ℃.Ya mere, ịbawanye ogo nke microphase nkewa na elastomers bụ otu n'ime ụzọ dị irè iji meziwanye nguzogide okpomọkụ ha.
Enwere ike imeziwanye ogo microphase nkewa nke elastomers site n'ịgbanwe oke nkesa molekụla dị arọ nke akụkụ yinye yana ọdịnaya nke akụkụ yinye siri ike, si otú a na-eme ka nguzogide okpomọkụ ha dịkwuo elu.Ọtụtụ ndị nchọpụta kwenyere na ihe kpatara nkewa microphase na polyurethane bụ thermodynamic incompatibility n'etiti akụkụ dị nro na nke siri ike.Ụdị ihe ndọtị nke yinye, akụkụ siri ike na ọdịnaya ya, ụdị akụkụ dị nro, na njikọ hydrogen niile nwere mmetụta dị ukwuu na ya.
E jiri ya tụnyere ihe ndọtị diol yinye, ndị na-agbatị diamine dị ka MOCA (3,3-dichloro-4,4-diaminodiphenylmethane) na DCB (3,3-dichloro-biphenylenediamine) na-etolite ọtụtụ amino ester amino ester na elastomer, yana ọtụtụ njikọ hydrogen nwere ike. a ga-etolite n'etiti akụkụ siri ike, na-amụba mmekọrịta dị n'etiti akụkụ siri ike na imeziwanye ogo microphase nkewa na elastomer;Ihe ndọtị nke yinye aromatic Symmetric dị ka p, p-dihydroquinone, na hydroquinone bara uru maka ịhazigharị na ịchịkọta akụkụ siri ike, si otú a na-emeziwanye nkewa microphase nke ngwaahịa.
Akụkụ amino ester nke aliphatic isocyanates hibere nwere ezigbo ndakọrịta na akụkụ dị nro, na-eme ka akụkụ ndị siri ike na-agbaze na akụkụ dị nro, na-ebelata ogo nkewapụ microphase.Akụkụ amino ester guzobere site na aromatic isocyanates enweghị ndakọrịta nke ọma na akụkụ dị nro, ebe ogo microphase nkewa dị elu.Polyolefin polyurethane nwere ihe fọrọ nke nta ka ọ bụrụ usoro nkewa nkewa microphase zuru oke n'ihi eziokwu ahụ bụ na akụkụ dị nro anaghị emepụta njikọ hydrogen na njikọ hydrogen nwere ike ime naanị na akụkụ siri ike.
Mmetụta hydrogen bonding na ebe nro nke elastomers dịkwa ịrịba ama.Ọ bụ ezie na polyethers na carbonyls na akụkụ dị nro nwere ike ịmepụta ọnụ ọgụgụ dị ukwuu nke njikọ hydrogen na NH na akụkụ siri ike, ọ na-abawanye okpomọkụ nke dị nro nke elastomers.Ekwenyere na njikọ hydrogen ka na-ejigide 40% na 200 ℃.
02 Thermal ire ere
Otu Amino ester na-enweta ire ere na oke okpomọkụ:
- RNHCOOR – RNC0 HO-R
- RNHCOOR - RNH2 CO2 ene
- RNHCOOR - RNHR CO2 ene
Enwere ụdị atọ bụ isi nke ire ere nke ihe ndị dabere na polyurethane:
① Ịmepụta isocyanates na polyols mbụ;
② α- Njikọ oxygen na ntọala CH2 na-agbaji wee jikọta ya na njikọ hydrogen na CH2 nke abụọ iji mepụta amino acid na alkenes.Amino acids na-emebi n'ime otu amine na carbon dioxide:
③ Ụdị amine nke abụọ na carbon dioxide.
Thermal ire ere nke usoro carbamate:
Aryl NHCO Aryl, ~ 120 ℃;
N-alkyl-NHCO-aryl, ~ 180 ℃;
Aryl NHCO n-alkyl, ~ 200 ℃;
N-alkyl-NHCO-n-alkyl,~250 ℃.
Nkwụsi ike nke okpomọkụ nke esters amino acid metụtara ụdị mmalite ihe dị ka isocyanates na polyols.Aliphatic isocyanates dị elu karịa aromatic isocyanates, ebe mmanya ndị nwere abụba dị elu karịa mmanya na-esi ísì ụtọ.Otú ọ dị, akwụkwọ akụkọ na-akọ na okpomọkụ decomposition nke aliphatic amino acid esters dị n'etiti 160-180 ℃, na nke aromatic amino acid esters dị n'etiti 180-200 ℃, nke na-ekwekọghị na n'elu data.Ihe kpatara ya nwere ike jikọta na usoro nyocha.
N'ezie, aliphatic CHDI (1,4-cyclohexane diisocyanate) na HDI (hexamethylene diisocyanate) nwere nguzogide okpomọkụ ka mma karịa MDI aromatic na TDI.Karịsịa trans CHDI nwere usoro ihe atụ ka amatala dị ka isocyanate kachasị na-eguzogide okpomọkụ.Polyurethane elastomers nke a kwadebere na ya nwere usoro nhazi dị mma, nguzogide hydrolysis dị mma, okpomọkụ dị nro dị nro, obere iko mgbanwe okpomọkụ, obere hysteresis thermal, na elu UV.
Na mgbakwunye na amino ester otu, polyurethane elastomers nwekwara ndị ọzọ na-arụ ọrụ dị iche iche dị ka urea formate, biuret, urea, wdg. Ndị a nwere ike na-enweta thermal decomposition na elu okpomọkụ:
NHCONCOO - (aliphatic urea formate), 85-105 ℃;
- NHCONCOO - (urea formate aromatic), na oke okpomọkụ nke 1-120 ℃;
- NHCONCONH - (aliphatic biuret), na okpomọkụ sitere na 10 Celsius C ruo 110 Celsius;
NHCONCONH - ( aromatic biuret), 115-125 ℃;
NHCONH - (urea aliphatic), 140-180 ℃;
- NHCONH - (urea aromatic), 160-200 ℃;
Isocyanurate mgbanaka> 270 ℃.
The thermal decomposition okpomọkụ nke biuret na urea dabeere formate dị nnọọ ala karịa nke aminoformate na urea, ebe isocyanurate nwere kasị mma thermal kwụsie ike.N'ime mmepụta nke elastomers, oke isocyanates nwere ike meghachi omume na aminoformate na urea a kpụrụ akpụ iji mepụta usoro urea na biuret nwere njikọ.Ọ bụ ezie na ha nwere ike imeziwanye ihe ndị na-arụ ọrụ nke elastomers, ha na-esiwanye ike ikpo ọkụ.
Iji belata thermal ejighị n'aka dị ka biuret na urea formate na elastomers, ọ dị mkpa iji tụlee ha akụrụngwa ruru na mmepụta usoro.Ekwesịrị iji oke oke isocyanate mee ihe, a ga-ejikwa ụzọ ndị ọzọ dị ka enwere ike ibu ụzọ mepụta mgbanaka isocyanate akụkụ na akụrụngwa (karịsịa isocyanates, polyols, na chain extenders), wee webata ha n'ime elastomer dị ka usoro nkịtị si dị.Nke a aghọwo ụzọ a na-ejikarị eme ihe maka ịmepụta polyurethane elastomer na-eguzogide ọkụ na ọkụ.
03 Hydrolysis na thermal oxidation
Polyurethane elastomer na-adịkarị mfe ire ere na akụkụ ha siri ike yana mgbanwe kemịkalụ kwekọrọ na akụkụ ha dị nro na oke okpomọkụ.Polyester elastomers nwere oke mmiri na-eguzogide mmiri yana ọchịchọ siri ike nke hydrolyze na okpomọkụ dị elu.Ndụ ọrụ nke polyester/TDI/diamine nwere ike iru ọnwa 4-5 na 50 ℃, naanị izu abụọ na 70 ℃, na naanị ụbọchị ole na ole karịa 100 ℃.Njikọ Ester nwere ike imebi n'ime acids na alcohols kwekọrọ na mmiri ọkụ na uzuoku, na urea na amino ester dị na elastomer nwekwara ike nweta mmeghachi omume hydrolysis:
RCOOR H20- → RCOOH HOR
Ester mmanya
Otu RNHCONHR otu H20- → RXHCOOH H2NR -
Ureamide
Otu RNHCOOR-H20- → RNCOOH HOR -
Amino formate ester Amino formate mmanya
Polyether dabeere elastomers nwere ogbenye thermal oxidation nkwụsi ike, na ether dabeere elastomers α- The hydrogen na carbon atom na-adị mfe oxidized, na-akpụ a hydrogen peroxide.Mgbe mwepu ọzọ na mgbawa, ọ na-emepụta radicals oxide na hydroxyl radicals, nke na-emecha decompose n'ime formates ma ọ bụ aldehydes.
Polyester dị iche iche na-enwe mmetụta dị nta na nguzogide okpomọkụ nke elastomers, ebe polyester dị iche iche nwere mmetụta ụfọdụ.Tụnyere na TDI-MOCA-PTMEG, TDI-MOCA-PTMEG nwere a tensile ike njide ọnụego nke 44% na 60% karị mgbe agadi na 121 ℃ maka 7 ụbọchị, na nke ikpeazụ dị nnọọ mma karịa nke mbụ.Ihe kpatara ya nwere ike ịbụ na ụmụ irighiri ihe PPG nwere agbụ nke alaka, nke na-adịghị akwado nhazi oge niile nke ụmụ irighiri ihe na-agbanwe agbanwe ma belata nguzogide okpomọkụ nke ahụ na-agbanwe.Usoro nkwụsi ike nke okpomọkụ nke polyethers bụ: PTMEG>PEG>PPG.
Otu ndị ọzọ na-arụ ọrụ na polyurethane elastomer, dị ka urea na carbamate, na-enwetakwa mmeghachi omume oxidation na hydrolysis.Otú ọ dị, otu ether bụ nke kachasị mfe oxidized, ebe ester otu bụ nke kachasị mfe hydrolyzed.Usoro nke antioxidant ha na nguzogide hydrolysis bụ:
Ọrụ antioxidant: esters>urea>carbamate>ether;
Hydrolysis eguzogide: ester
Iji meziwanye nguzogide oxidation nke polyether polyurethane na mgbochi hydrolysis nke polyester polyurethane, a na-agbakwunyekwa ihe mgbakwunye, dị ka ịgbakwunye 1% phenolic antioxidant Irganox1010 na PTMEG polyether elastomer.Enwere ike ịbawanye ike ike nke elastomer a ugboro 3-5 ma e jiri ya tụnyere enweghị antioxidants (nnwale ule mgbe ịka nká na 1500C maka awa 168).Ma ọ bụghị antioxidant ọ bụla nwere mmetụta na polyurethane elastomers, naanị phenolic 1rganox 1010 na TopanOl051 (phenolic antioxidant, egbochi amine light stabilizer, benzotriazole complex) nwere mmetụta dị ịrịba ama, na nke mbụ bụ nke kacha mma, ikekwe n'ihi na phenolic antioxidants nwere ezigbo ndakọrịta na elastomers.Otú ọ dị, n'ihi ọrụ dị mkpa nke ìgwè phenolic hydroxyl na usoro nkwụsi ike nke antioxidants phenolic, iji zere mmeghachi omume na "ọdịda" nke ìgwè phenolic hydroxyl a na ndị otu isocyanate na usoro ahụ, oke nke isocyanates na polyols ekwesịghị ịbụ. buru oke ibu, na a ga-agbakwunye antioxidants na prepolymers na ndị na-eke agbụ.Ọ bụrụ na agbakwunyere n'oge mmepụta nke prepolymer, ọ ga-emetụta mmetụta nkwụsi ike nke ukwuu.
Ihe mgbakwunye eji egbochi hydrolysis nke polyester polyurethane elastomer bụ tumadi carbodiimide ogige, nke na-emeghachi omume na carboxylic acid nke ester hydrolysis na-emepụta na polyurethane elastomer molecules iji mepụta acyl urea derivatives, na-egbochi ọzọ hydrolysis.Mgbakwunye nke carbodiimide na ọnụ ọgụgụ dị nta nke 2% ruo 5% nwere ike ịbawanye nkwụsi ike nke polyurethane site na ugboro 2-4.Na mgbakwunye, tert butyl catechol, hexamethylenetetramine, azodicarbonamide, wdg nwekwara mmetụta mgbochi hydrolysis ụfọdụ.
04 Isi njirimara arụmọrụ
Polyurethane elastomers bụ ụdị copolymers multi block, nke nwere ụdọ molekụla mejupụtara akụkụ na-agbanwe agbanwe na iko mgbanwe okpomọkụ dị ala karịa ụlọ okpomọkụ na akụkụ siri ike na iko mgbanwe okpomọkụ dị elu karịa ụlọ okpomọkụ.N'ime ha, polyols oligomeric na-etolite akụkụ ndị na-agbanwe agbanwe, ebe diisocyanates na obere ihe ndọtị molecule na-etolite akụkụ siri ike.Usoro agbakwunyere nke akụkụ yinye na-agbanwe agbanwe na nke siri ike na-ekpebi arụmọrụ ha pụrụ iche:
(1) Oke siri ike nke rọba nkịtị na-adịkarị n'etiti Shaoer A20-A90, ebe ike siri ike nke plastik bụ Shaoer A95 Shaoer D100.Polyurethane elastomers nwere ike iru ala dị ka Shaoer A10 ma dị elu dị ka Shaoer D85, na-enweghị mkpa enyemaka enyemaka;
(2) A ka nwere ike ịnọgide na-enwe ike dị elu na elasticity n'ime ọtụtụ ihe siri ike;
(3) Nguzogide iyi mara mma, 2-10 ugboro nke roba eke;
(4) Nnukwu iguzogide mmiri, mmanụ, na kemịkal;
(5) Mmetụta mmetụta dị elu, nkwụsị ike ọgwụgwụ, na nkwụsị nke vibration, kwesịrị ekwesị maka ngwa na-ehulata elu ugboro ugboro;
(6) Ezigbo nguzogide okpomọkụ dị ala, nke nwere obere okpomọkụ n'okpuru -30 ℃ ma ọ bụ -70 ℃;
(7) Ọ na-arụ ọrụ mkpuchi dị mma, na n'ihi nkwụsị ọkụ ọkụ ya dị ala, ọ nwere mmetụta mkpuchi ka mma ma e jiri ya tụnyere roba na plastik;
(8) Ezi biocompatibility na anticoagulant Njirimara;
(9) Ihe mkpuchi eletrik mara mma, nguzogide ebu, na nkwụsi ike UV.
Enwere ike ịmepụta elastomer polyurethane site na iji otu usoro dị ka roba nkịtị, dị ka plasticization, ịgwakọta, na vulcanization.Enwere ike ịkpụzi ha n'ụdị rọba mmiri mmiri site na ịwụsa, ịkpụzi centrifugal, ma ọ bụ ịgbasa.A pụkwara ime ha ka ọ bụrụ ihe granular ma kpụrụ ya site na iji injection, extrusion, mpịakọta, ịkpụzi ihe, na usoro ndị ọzọ.N'ụzọ dị otú a, ọ bụghị nanị na ọ na-eme ka arụmọrụ ọrụ dịkwuo mma, kamakwa ọ na-eme ka akụkụ ziri ezi na ọdịdị nke ngwaahịa ahụ dịkwuo mma.
Oge nzipu: Dec-05-2023