Da abin da ake kirapolyurehaneShin raguwa ne na polyurehane, wanda aka kafa ta hanyar amsawa da polyisocyanates da polyols, kuma ya sa maimaita yawancin ƙungiyoyin Amino EST (- NH-Co-O - a kan sarkar kwayoyin. A cikin ainihin samar da polyurethane resins, ban da ƙungiyar Amino ester, akwai kuma kungiyoyi kamar ureta da biure. Polyols suna cikin kwayoyin halitta masu dadewa tare da kungiyoyin hydroxyl a ƙarshen, waɗanda ake kira "sarkar sarkar sarkar sarkar ana kiransu" wuya sarkar sarkar sarkoki ".
Daga cikin abubuwan polyurethane na samar da sarkar sarkar taushi da kuma karamin kashi ne masu daidaitaccen amino active, don haka bazai dace da kiran su polyurthane ba. A cikin babban hankali, polyurethane shine ƙarin sigari.
Nau'ikan isocyanates suna amsawa tare da mahaɗan polyhydroxy don samar da nau'ikan polyurthanes tare da wasu abubuwa daban-daban, kamar roba, roba, da sauransu.
Polyurethane roba nasa ne na musamman na roba, wanda ke amsawa ta hanyar mai ba da polyither ko polyester tare da isocyanate. Akwai nau'ikan da yawa saboda nau'ikan albarkatun ƙasa daban-daban, yanayin amsawa, da hanyoyin masu tsafta. Daga tsarin sunadarai, akwai nau'ikan polyester da nau'in kayan kwalliya, kuma daga tsarin sarrafawa, akwai nau'ikan guda uku: nau'in haɗawa, da nau'in haɗaɗe, da nau'in hemfoplast.
Rynthane Rynurethane roba gabaɗaya ta mayar da kayan aikin polyester ko polyither tare da diiscularate don samar da nauyin sarkar kayan aiki don ƙirƙirar polymer nauyi kwayar cuta. Bayan haka, an ƙara wakilan masu fasahar da suka dace kuma ana mai zafi don warkar da shi, zama roba mai rauni. Ana kiran wannan hanyar prepolymerization ko hanya biyu-biyu.
Hakanan yana yiwuwa a yi amfani da hanyar mataki ɗaya - haɗa haɗi kai tsaye ko polyter tare da diiscyanates, sarkar sarkar, da kuma masu fasahar ruwa don fara roba na polyurthane.
A-kashi a cikin kwayoyin TPU suna sa masu ɗaukar hoto mai sauƙi don juyawa, suna ba da damar wucewa da sakandare na polymer, da rage girman ƙarfin sa da injiniya. A B-sashi zai ɗaure subation na macromemecular sarƙoƙi da na sakandare na polymer don ƙara, ƙarfi na yau da kullun, da raguwar elasticity. Ta hanyar daidaita matsayin Mark. Tsarin haɗin gwiwar TPU dole ne kawai la'akari da bayanan firamare-haɗi, amma kuma haɗin gwiwa na sakandare wanda aka haɗa shi ta hanyar hydrogen parts tsakanin kwayoyin. Babban haɗin gwiwar na farko na polyurethane daga tsarin rashin daidaituwa na roba na hydroxyl. Kungiyar ETRES ta Amino, kungiyoyin Biure, kungiyoyin urea na shirya tsarin sarkar na yau da kullun, wanda yake da kyakkyawan sa juriya da sauran kyawawan kaddarorin yau. Abu na biyu, saboda kasancewar da yawa masu aiki tare kamar urea ko kungiyoyin hysuregate da ya kafa tsakanin sarƙoƙin na kayan kwalliya kuma suna da tasiri sosai akan roba na polyurthane. Sakandare na sakandare yana ba da roba na polyurthane don su mallaki halayen thermomers a gefe ɗaya, kuma a gefe guda, wannan haɗin haɗin ba da haɗin gwiwa ba, yana sa shi da alaƙa da haɗin kai. Yanayin haɗi ya dogara da zazzabi. Kamar yadda zafin jiki ya karu, wannan tsallake-haɗi a hankali ya raunana kuma ya ɓace. Polymer yana da wasu ruwa mai ruwa kuma ana iya haɗawa da aiki mai narkewar thermoplast. Lokacin da zazzabi ya ragu, wannan giciye-haɗe a hankali ya murmure da kuma siffofin sake. Additionarin karamin adadin filler yana ƙaruwa da nisa tsakanin kwayoyin, raunin ikon samar da kayan haɗin hydrogen tsakanin kwayoyin, kuma yana haifar da raguwa cikin ƙarfi. Bincike ya nuna cewa tsari na zaman lafiya na kungiyoyi daban-daban a cikin roba polyurthane daga babban zuwa karancin shi ne: ester, urea, carbamate, da kuma misali, da kuma biuret. A lokacin tsufa na roba na polyurethane, mataki na farko shine rabuwar bangarorin haɗin haɗe tsakanin biuret da urea, biye da karya parbamate da urea, biye da karar sarkar.
01 Softening
Polyurethane Elastomers, kamar abubuwa da yawa polymer, laushi a babban yanayin zafi da canji daga jihar kwarara na gaba zuwa ga jihar kwarara ta viscous, wanda ya haifar da raguwa a cikin ƙarfin injin. Daga mahangar mai guba, zazzabi mai laushi na elasticity musamman dogara da abubuwan da ke ciki, ƙwayoyin ƙwayar ƙwayar cuta, da kuma yawan ƙwayoyin cuta.
Gabaɗaya magana, ƙara nauyin ƙwayar ƙwayar ƙwayar ƙwarewa, ƙara yawan zobe na bencule) da kuma ƙara yawan kere-kere, da kuma ƙara yawan ƙwayoyin cuta don ƙara yawan zafin jiki. Don thermoplastic olastomers, tsarin kwayar halitta shine yafi layin, kuma zazzabi mai laushi na Elastomer kuma yana ƙaruwa lokacin da nauyin kwayar kwayar cuta ke ƙaruwa.
Ga polyuretomers na gyaran polyuretomers, yawan crossinking yana da babban tasiri fiye da nauyi kwayoyin halitta. Sabili da haka, lokacin da masana'antu da aski, ƙara yawan ayyukan polyols na iya samar da tsarin haɗin kai na gidaje, ko amfani da rakiyar ruwa mai ƙarfi a cikin jiki na roba.
Lokacin da PPDI (P-PhenyLDIISCYANISCYAN) ana amfani da shi azaman albarkatun ƙasa, saboda haɗin gwiwar kai tsaye zuwa gaɓar benzene, wanda ya inganta juriya na benzene.
Daga hangen nesa na zahiri, zazzabi mai laushi na ealastomers ya dogara da matakin rabuwar microphase. A cewar rahotanni, zazzabi mai laushi na elastomers wanda baya daukar rabuwa da microphasse na kimanin 70 ℃, yayin da ℃, yayin da ℃asters da suka saba kai ga 130-150 ℃. Sabili da haka, ƙara digiri na rarrabuwar kawuna a cikin ealastomers yana ɗayan ingantattun hanyoyin don inganta juriya na zafi.
Digiri na Microphase rabuwa da ealastomers za a iya inganta ta hanyar canza rarraba sarkar sarkar da kuma abun da ke hana sarkar sarkar, ta haka inganta juriya da zafi. Yawancin masu binciken sun yi imani cewa dalilin microphasse ne mawuyacin hali tsakanin sassan mai taushi da wahala. Nau'in sarkar sarkar, yanki mai wuya da abun ciki, nau'in sumbin sa, kuma haɗin hydrogen duk suna da tasiri sosai akan sa.
Compared with diol chain extenders, diamine chain extenders such as MOCA (3,3-dichloro-4,4-diaminodiphenylmethane) and DCB (3,3-dichloro-biphenylenediamine) form more polar amino ester groups in elastomers, and more hydrogen bonds can be formed between hard segments, increasing the interaction between hard segments and improving the degree na lalata microphase a cikin elastomers; Symmetric sarkar mai tsawaita irin su kamar P, P-Dydroquinone suna da amfani ga daidaituwa da kuma m fakitin sassa, don ta inganta rabuwa da kayayyakin microphasse.
Amino ESTE sassan da Alipatic Isocyanates ta hanyar Aliphatantanates suna da dacewa da kyau tare da sassan m baƙaƙewa a cikin sassan da ke taushi, suna rage digiri na rarrabuwar kawuna. Amino ester sassan kayan Amino sun kirkiro ta Aromatic Isocyanates suna da karfinci mara kyau tare da sassan laushi, yayin da digiri na rabuwar microphase ya fi girma. Polyurefin Polyurethanin Polyurethane yana da kusan cikakkiyar tsari na microphases na lalata saboda gaskiyar cewa ɓangaren laushi ba ya haifar da haɗin hydrogen da haɗin hydrogen na iya faruwa ne kawai a cikin sashe mai wuya.
Tasirin sadarwar hydrogen a kan matun na ealastomers shima yana da muhimmanci. Kodayake polyethers da carbonys a cikin sumber sashi na iya samar da babban adadin hydrogen shaidu tare da nh a cikin wuya sashin. An tabbatar da cewa bangarorin hydrogen har yanzu suna riƙe da 40% a 200 ℃.
02 Rashin lalacewa
Kungiyoyin Amino na Amino sun sha kashi masu zuwa a babban yanayin zafi:
- rnhcoor - rnc0 ho-r
- RNHCOOR - RNH2 CO2 KYAU
- RNHCOOR - RNHR CO2 KYAU
Akwai manyan nau'ikan nau'ikan kayan aikin theryurehane na kayan polyurehane:
① forming Onange Oricyanates da polyols;
Haɗin oxygen a kan Bandunan Oxgen a kan Bands na Ch2 kuma ya haɗu da haɗin hydrogen guda ɗaya akan Ch2 don samar da amino acid da kuma alchenes. Amino acid din bazu zuwa cikin amine ɗaya na yau da kullun da carbon dioxide:
③ form 1 sakandare amine da carbon dioxide.
Rashin Tsarin Thermal na Carbamate:
Aryl Nhco Aryl, ~ 120 ℃;
N-Alkyl-Nhco-Aryl, ~ 180 ℃;
Aryl Nhco n-alkyl, ~ 200 ℃;
N-alkyl-Nhco-n-alkyl, ~ 250 ℃.
Haske na rashin lafiyar amino acid yana da alaƙa da nau'ikan farkon kayan kamar iotocyanates da polyols. Aliphatic Isocyanates sun fi na iromic isasancanatees, yayin da kakar kitsens sun fi giya mai ƙanshi. Koyaya, littattafan sun ba da rahoton cewa yawan zafin jiki na ƙwayar cuta na aliphatic amino acid shine tsakanin 160-200, wanda ba shi da daidaituwa tare da bayanan da ke sama. Dalilin na iya danganta da hanyar gwajin.
A zahiri, Aliphatic Chdi (1,4-Cycllohexane) da HDI (Hexamethylene Diisecyanate) suna da mafi kyawun headtawa fiye da yadda aka yi amfani da shi da yawa na ƙanshi da kuma TDI. Musamman trans chi tare da tsarin symmetrical an yarda da tsarin da aka fi tsayayya da zafi-mai tsayayya da zafi. Polyurethane Elastomers wanda aka shirya daga gare shi yana da kyawawan aiki, kyakkyawan zazzabi, zazzabi mai ƙarancin wuta, low therter hysteresis, da kuma babban juriya na gilashi.
Baya ga kungiyar Amino Estiters, Polyurethane Elastomers suma suna da wasu kungiyoyin aiki kamar su, da sauransu wadannan kungiyoyi na iya yin lalata da zafin rana:
Nhongcoo - (Aliphatic Urea formate), 85-105 ℃;
- Nhongcoo - (iromic Urea formate), a zazzabi kewayon 1-120 ℃;
- Nhoconconh - (Aliphatic biuret), a zazzabi tashi daga 10 ° C zuwa 110 ° C;
NHCONCONH - (Biurtic Biure), 115-125 ℃;
NHCONH - (Aliphatic Urea), 140-180 ℃;
- NHCHCH - (iromatik Urea), 160-200 ℃;
Otecyanurate ling> 270 ℃.
Tsarin zafin jiki na Thermal da UREA da aka tsara suna ƙasa da na Aminoformate da urea, yayin da isocyanurate yana da mafi kyawun kwanciyar hankali. A cikin samar da elastomers, isocyanates da yawa na iya ƙara amsa tare da kafa Aminoformate da urea don samar da tushen tushen tsari da kuma tsarin haɗin kai. Kodayake suna iya inganta kayan aikin kayan elastomers, suna da matukar rashin iya zafi.
Don rage ƙungiyoyi marasa amfani kamar ta'addanci kamar su biuret da urea suna tsari a cikin ealastomers, ya zama dole a la'akari da ragin kayan shayar da su. Ya kamata a yi amfani da Ratios na Isocyanate, da sauran hanyoyin da zai yiwu a yi amfani da su gwargwadon abin da ya dace, sannan kuma suka gabatar da su cikin tsari na yau da kullun. Wannan ya zama hanyar da aka saba amfani don samar da zafi-resistant da harshen wuta mai tsattsauran ra'ayi mai tsattsauran ra'ayi.
03 hydrolysis da hadawan abu da iskar shaye-shaye
Polyurethane Elastomers suna iya yiwuwa ga lalata a cikin sassan jikinsu da kuma canje-canje sunadarai a cikin sassan jikinsu mai laushi. Polyester Elastomers suna da kyawawan juriya da ruwa da kuma mafi tsananin rauni ga hydrorole a babban yanayin zafi. Rayuwar sabis na Polyester / TDI / Diamine na iya kai wa watanni 4-5 a 50 ℃, makonni biyu kawai a 70 ℃, kuma kawai 'yan kwanaki sama da 100 ℃. Bond Bonds na iya lalata cikin ruwan acid da giya lokacin da aka fallasa ruwan zafi da tururi, da urea da esato kungiyoyi a cikin ealastomers ma zasu iya yin amfani da hydrolysis:
RCOOR H20- → rcoh hor
Ester giya
Daya Rnhconhr daya H20- → rxhcooh h2nr -
Ureamide
RNHCOOR-h20- → rncooh -
Amino formatate Ester Amin formate
Polyether tushen ealastomers suna da kwanciyar hankali na overidation na ciki, da ether etheromers α- da hydrogen a kan carbon carmon carbon carom yana da sauƙin oxidized, samar da hydren peroxide. Bayan runtushawar, yana haifar da tsattsarkan tsattsarkan iri-iri da hydroxyl Radicals, wanda a ƙarshe bazu zuwa cikin tsari ko alkama.
Bambancin polyesters daban-daban ba su da ƙarancin tasiri a kan jure zafin ruwan ealastomers, yayin da polyeth daban-daban suna da wani tasiri. Idan aka kwatanta da TDI-MOCA-PTMEG, TDI-MOCA-PTMec-PTMEG yana da yawan adadin kudaden da ke tattare da kashi 44% kuma 60% suka bi kusan kwanaki 121 ℃ na kwanaki 71, tare da na karshen kwanaki sun fi na farkon. Dalilin na iya zama cewa kwayoyin ppg suna da sarƙoƙi na yau da kullun, waɗanda ba su da hankali ga tsarin yau da kullun na kwayoyin halittar ruwa da rage juriya na roba. Tsarin kwanciyar hankali na kayan kwalliyar kayan kwalliya shine: PTMEG> Peng> ppg.
Sauran kungiyoyin aiki a Polyurethane Elastomers, kamar urea da carbamate, kuma suna yin iskar iskar iskar haushi da hydrolysis. Koyaya, ƙungiyar ether ita ce mafi sauƙin ciki, yayin da rukunin Ester shine mafi sauƙin hydroyzed. Odar su maganin antioxidant da hydrolyis juriya shine:
Aikin Anoxidant: Essters> Urea> Urea> ur carbamate> Ether;
Hydrolyis juriya: ester
Don inganta juriya na iskar shaka da ruwan polyter da hydrolyis na Polyurethane, ƙara pheneteter attanox1010 zuwa PTMEG PITY ENTETER Elastox1010 zuwa PTMEG Za'a iya ƙara ƙarfin wannan elastomer na wannan elastomer sau 3-5 idan aka kwatanta da cututtukan antioxidants (sakamakon gwaji bayan tsufa a 1500C na awanni 168). Amma ba kowane antioxidant yana da tasiri a polyurthane use elastomers, kawai phenolol 1010 da kuma saman ƙwararru mai kyau, wataƙila saboda antioxidants mai kyau tare da elastomers. Koyaya, saboda muhimmiyar rawa ta fa'idar kungiyoyin da ke haifar da maganin antioxidants ta antioxidants bai kamata a ƙara su da prolyols ba da "garooxyanates ga polyols kada a kara su zuwa prolyols da masu kawo antioxidants. Idan an kara shi yayin samar da prospomers, zai shafi ingantaccen sakamako.
Adadin da aka yi amfani da su don hana hydrolysis na polyser Polyurethane Elastomer na Carbodide, wanda ya amsa da Carboxy Elastomer Merboards, hana kara hydrativalysis. Additionarin carbodide a cikin wani yanki na 2% zuwa 5% na iya haɓaka kwanciyar hankali na ruwa na polyurethane ta 2-4 sau. Bugu da kari, Tert Butyl catechol, hexamethylenettraum, da sauransu kuma suna da wasu maganin hana hydrolyis.
04 Babban halayen aikin
Polyurethane Elastomers suna da yawa na copolymers da yawa, tare da sarƙoƙin kwayoyin halitta da suka ƙunshi zafin jiki mai sauƙi tare da yanayin yanayin zafin jiki sama da zazzabi. Daga cikinsu, polyols polyols ya ƙira sassauƙa mai sauƙaƙe, yayin da diiscyanannes da ƙananan kwayoyin sarkar sarkar sittin da aka kawo tsayayyen sassan. Tsarin da aka saka na sassauƙa da ƙwayoyin sarkar sarkar suna tantance aikinsu na musamman:
(1) Hardness kewayon roba na yau da kullun yana tsakanina da20-A90, yayin da wuya na filastik shine game da Shooer A95 Toer D100. Polyurethane Elastomers na iya kaiwa har ƙasa kamar yadda A10 kuma kamar yadda high kamar yadda Shaoer d85, ba tare da buƙatar taimako taimako ba;
(2) Har yanzu ana iya tabbatar da karfin karfi da kuma ana iya ci gaba da elebistitity a cikin yaduwar wuya;
(3) kyakkyawan sa jingina, 2-10 sau da na roba na zahiri;
(4) kyakkyawan juriya ga ruwa, man, da sunadarai;
(5) Babban Hanya Juriya, Fatigue juriya, da juriya na rigakafi, dace da aikace-aikacen da ya dace da aikace-aikacen miji;
(6) Kyakkyawan juriya mai ƙarfi, tare da ƙarancin zafin jiki da ƙasa -30 ℃ ko -70 ℃;
(7) Yana da matsanancin rufi, kuma saboda shi mai ƙarancin zafin jiki, yana da mafi kyawun hauhawar ruɗi idan aka kwatanta shi da roba da filastik;
(8) Biocompattibility da anticoululant kadari;
(9) Mak su da rufi na lantarki, juriya na mold, da kuma kwanciyar hankali UV.
Za'a iya samar da aski na polyurethane ta amfani da wannan tafiyar matakai kamar yadda na yau da kullun, kamar filastik, hadawa, da rashin jituwa. Hakanan za'a iya sarrafa su a cikin hanyar roba mai ruwa ta hanyar zubowa, centrifugal m -ing, ko spraying. Hakanan ana iya yin su cikin kayan granadade kuma an kafa su ta amfani da allura, iska, mirgina, busa mai ƙarfi, da sauran hanyoyin. Ta wannan hanyar, ba wai kawai yana inganta ingantaccen aiki ba, amma kuma yana inganta daidaito da yanayin samfurin
Lokaci: Dec-05-2023