Kupita Patsogolo kwa Kafukufuku pa Polyurethanes Zosakhala za Isocyanate
Kuyambira pomwe zidayambitsidwa mu 1937, zinthu za polyurethane (PU) zakhala zikugwiritsidwa ntchito kwambiri m'magawo osiyanasiyana kuphatikizapo mayendedwe, zomangamanga, mafuta, nsalu, uinjiniya wamakina ndi zamagetsi, ndege, chisamaliro chaumoyo, ndi ulimi. Zinthuzi zimagwiritsidwa ntchito m'njira monga pulasitiki ya thovu, ulusi, ma elastomers, zinthu zotetezera madzi, chikopa chopangidwa, zokutira, zomatira, zinthu zopaka pakhoma ndi zinthu zamankhwala. PU yachikhalidwe imapangidwa makamaka kuchokera ku isocyanate ziwiri kapena zingapo pamodzi ndi ma polyols a macromolecular ndi zokulitsa zazing'ono za molecular chain. Komabe, poizoni wobadwa nawo wa isocyanate umabweretsa zoopsa zazikulu pa thanzi la anthu ndi chilengedwe; komanso nthawi zambiri zimachokera ku phosgene - chinthu choyambitsa poizoni kwambiri - komanso zinthu zopangira amine zofanana.
Poganizira za makampani amakono opanga mankhwala omwe akufuna njira zobiriwira komanso zokhazikika, ofufuza akuyang'ana kwambiri kusintha ma isocyanates ndi zinthu zosawononga chilengedwe pamene akufufuza njira zatsopano zopangira ma polyurethanes osagwiritsa ntchito isocyanate (NIPU). Pepalali likuwonetsa njira zokonzekera NIPU pamene likuwunikanso kupita patsogolo kwa mitundu yosiyanasiyana ya NIPU ndikukambirana za tsogolo lawo kuti apereke chitsogozo cha kafukufuku wowonjezera.
1 Kupanga kwa Polyurethanes Zosakhala za Isocyanate
Kupanga koyamba kwa mankhwala otsika a carbamate pogwiritsa ntchito monocyclic carbonates kuphatikiza ndi aliphatic diamines kunachitika kunja kwa dziko m'ma 1950—kumene kunali nthawi yofunika kwambiri pakupanga polyurethane yosakhala isocyanate. Pakadali pano pali njira ziwiri zazikulu zopangira NIPU: Yoyamba ikuphatikizapo kuwonjezera zochita pakati pa binary cyclic carbonates ndi binary amines; yachiwiri ikuphatikizapo polycondensation reactions yokhudza diurethane intermediates pamodzi ndi diols zomwe zimathandiza kusinthana kwa kapangidwe kake mkati mwa carbamates. Diamarboxylate intermediates ingapezeke kudzera mu njira za cyclic carbonate kapena dimethyl carbonate (DMC); njira zonse zimagwirira ntchito kudzera m'magulu a carbonic acid omwe amapereka ntchito za carbamate.
Magawo otsatirawa akufotokoza njira zitatu zosiyana zopangira polyurethane popanda kugwiritsa ntchito isocyanate.
1.1 Njira Yozungulira Kaboneti Yozungulira Binary
NIPU ikhoza kupangidwa kudzera mu zowonjezera pang'onopang'ono zomwe zimaphatikizapo binary cyclic carbonate yolumikizidwa ndi binary amine monga momwe zasonyezedwera pa Chithunzi 1.
Chifukwa cha magulu angapo a hydroxyl omwe amapezeka mkati mwa mayunitsi obwerezabwereza motsatira kapangidwe kake ka unyolo waukulu, njira imeneyi nthawi zambiri imapanga zomwe zimatchedwa polyβ-hydroxyl polyurethane (PHU). Leitsch et al., adapanga ma PHU angapo a polyether pogwiritsa ntchito ma polyethers otsirizidwa ndi cyclic carbonate pamodzi ndi ma binary amines kuphatikiza mamolekyu ang'onoang'ono ochokera ku binary cyclic carbonates—kuyerekeza izi ndi njira zachikhalidwe zomwe zimagwiritsidwa ntchito pokonzekera ma PU a polyether. Zomwe adapeza zidawonetsa kuti magulu a hydroxyl mkati mwa ma PHU amapanga mosavuta ma hydrogen bond ndi ma atomu a nitrogen/oxygen omwe ali mkati mwa magawo ofewa/olimba; kusiyana pakati pa magawo ofewa kumakhudzanso machitidwe a hydrogen bonding komanso madigiri olekanitsa a microphase omwe pambuyo pake amakhudza machitidwe onse ogwira ntchito.
Kawirikawiri imachitika kutentha kopitilira 100 °C njira iyi sipanga zinthu zina panthawi yochita zinthu zomwe zimapangitsa kuti ikhale yosakhudzidwa ndi chinyezi pomwe imapanga zinthu zokhazikika popanda nkhawa zosinthasintha koma imafuna zosungunulira zachilengedwe zomwe zimakhala ndi polarity yamphamvu monga dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), ndi zina zotero. Kuphatikiza apo, nthawi yayitali yochitira zinthu kuyambira tsiku limodzi mpaka masiku asanu nthawi zambiri imapereka kulemera kochepa kwa mamolekyulu nthawi zambiri kumakhala kocheperako pansi pa malire pafupifupi 30k g/mol zomwe zimapangitsa kupanga kwakukulu kukhala kovuta chifukwa cha mtengo wokwera womwe umagwirizana ndi izi komanso mphamvu yosakwanira yomwe imawonetsedwa ndi ma PHU omwe amabwera ngakhale kuti ntchito zabwino zimafalikira pakati pa zinthu zosungiramo zinthu, mawonekedwe a kukumbukira, kapangidwe ka zomatira, mayankho ophimba, thovu, ndi zina zotero.
1.2 Njira ya Monocylic Carbonate
Monocylic carbonate imakhudzana mwachindunji ndi dicarbamate yomwe imachokera ku diamine yokhala ndi magulu a hydroxyl omwe amakumana ndi transesterification/polycondensation yapadera pamodzi ndi ma diols omwe pamapeto pake amapanga NIPU yofanana ndi yachikhalidwe yomwe ikuwonetsedwa m'chithunzi 2.
Mitundu ya monocylic yomwe imagwiritsidwa ntchito kwambiri ndi ethylene & propylene carbonated substrates pomwe gulu la Zhao Jingbo ku Beijing University Of Chemical Technology linagwiritsa ntchito ma diamondi osiyanasiyana omwe amawatsutsana ndi zinthu zomwe zimazungulira poyamba zomwe zimapeza ma dicarbamate intermediaries osiyanasiyana asanapitirire ku magawo a condensation pogwiritsa ntchito polytetrahydrofuranediol/polyether-diols zomwe zimapangitsa kuti mizere yazinthuzo ikhale yopambana, zomwe zimakhala ndi mphamvu zotentha/makina zomwe zimafika pamwamba pamalo osungunuka omwe amazungulira pafupifupi 125 ~ 161°C mphamvu zomangika zomwe zimafika pachimake pafupifupi 24MPa elongation rates pafupifupi 1476%. Wang et al., mofananamo, kuphatikiza komwe kumagwiritsa ntchito DMC komwe kumagwirizanitsidwa motsatana ndi hexamethylenediamine/cyclocarbonated precursors zomwe zimapanga hydroxy-terminated derivatives pambuyo pake zidayikidwa mu biobased dibasic acids monga oxalic/sebacic/acids adipic-acid-terephtalics akupeza zotsatira zomaliza zomwe zikuwonetsa milingo yozungulira 13k~28k g/mol tensile strengths fluctuating9~17 MPa elongations variables 35%~235%.
Ma ester a cyclocarbonic amagwira ntchito bwino popanda kugwiritsa ntchito ma catalyst pansi pa mikhalidwe yanthawi zonse, kusunga kutentha kumafikira pafupifupi 80°to 120°C, ma transesterification otsatira nthawi zambiri amagwiritsa ntchito njira zoyendetsera zinthu zochokera ku organotin zomwe zimaonetsetsa kuti kukonza bwino sikupitirira 200°. Kupatula kungoyesetsa kudzaza ndi ma condensation omwe amayang'ana ma diolic inputs omwe amatha kudzipanga okha/kuchotsa ma glycolysis omwe amapangitsa kuti pakhale zotsatira zomwe mukufuna, njirazi zimapangitsa kuti zikhale zotetezeka ku chilengedwe, zomwe zimapangitsa kuti zikhale zotsalira za methanol/molecule-diolic zomwe zimapanga ma residues ang'onoang'ono, motero zimapereka njira zina zogwirira ntchito zamafakitale.
1.3 Njira ya Dimethyl Carbonate
DMC ikuyimira njira ina yabwino/yopanda poizoni yomwe ili ndi zinthu zambiri zogwira ntchito kuphatikiza methyl/methoxy/carbonyl configurations zomwe zimakulitsa ma reactivity profiles zomwe zimathandiza kwambiri kuti DMC igwirizane mwachindunji ndi ma diamondi omwe amapanga ma intermediaries ang'onoang'ono a methyl-carbamate omwe amachotsedwa pambuyo pake, zomwe zimapangitsa kuti pakhale kusungunuka kwa methyl-carbamate komwe kumaphatikizapo zinthu zina zazing'ono-zowonjezera-diolics/polyol zazikulu zomwe zimapangitsa kuti mapangidwe a polymer omwe amafunidwa awonekere moyenerera kudzera pa Chithunzi 3.
Deepa et.al adagwiritsa ntchito mphamvu zomwe zatchulidwazi pogwiritsa ntchito sodium methoxide catalysis yomwe imapanga mapangidwe osiyanasiyana apakati kenako imagwiritsa ntchito zowonjezera zomwe zimafika kumapeto kwa mndandanda wofanana ndi magawo olimba omwe amafika kulemera kwa mamolekyulu pafupifupi (3 ~ 20)x10^3g/mol kutentha kwa kusintha kwa galasi komwe kumafikira (-30 ~ 120°C). Pan Dongdong adasankha ma pairings anzeru okhala ndi DMC hexamethylene-diaminopolycarbonate-polyalcohols omwe akupeza zotsatira zodziwika bwino zomwe zikuwonetsa mayendedwe amphamvu osasunthika 10-15MPa elongation ratios yomwe ikuyandikira 1000%-1400%. Kafukufuku wokhudza zinthu zosiyanasiyana zomwe zimapangitsa kuti pakhale unyolo wosiyanasiyana, wasonyeza kuti zomwe amakonda zimagwirizana bwino ndi kusankha kwa butanediol/hexanediol pamene chiwerengero cha atomiki chinasunga kufanana komwe kumathandizira kuti makristalo apangidwe bwino m'matchulidwe osiyanasiyana. Gulu la Sarazin linapanga zinthu zophatikizika zomwe zimagwirizanitsa lignin/DMC pamodzi ndi hexahydroxyamine zomwe zikuwonetsa mphamvu zabwino zamakina zomwe zimakonzedwa pambuyo pa 230℃. Kufufuza kwina komwe kunkafuna kupeza zinthu zopanda isocyante-polyurea pogwiritsa ntchito diazomonomer kunayembekezera kuti utoto ungagwiritsidwe ntchito bwino poyerekeza ndi zinthu zina za vinyl-carbonaceous zomwe zikuwonetsa kugwiritsa ntchito bwino ndalama/njira zambiri zopezera zinthu. Kufufuza mozama za njira zopangira zinthu zambiri nthawi zambiri kumafuna malo otentha kwambiri/opanda mpweya omwe amaletsa zofunikira zosungunulira motero kuchepetsa zinyalala zomwe zimatulutsa madzi a methanol/mamolekyulu ang'onoang'ono-diolic omwe amapanga njira zobiriwira zopangira zinthu.
Magawo awiri ofewa osiyanasiyana a polyurethane yopanda isocyanate
2.1 Polyether polyurethane
Polyether polyurethane (PEU) imagwiritsidwa ntchito kwambiri chifukwa cha mphamvu yake yocheperako ya ma ether bond m'magawo ofewa obwerezabwereza, kuzungulira kosavuta, kusinthasintha kwabwino kwambiri kwa kutentha kochepa komanso kukana hydrolysis.
Kebir ndi anzake adapanga polyether polyurethane ndi DMC, polyethylene glycol ndi butanediol ngati zopangira, koma kulemera kwa molekyulu kunali kochepa (7 500 ~ 14 800g/mol), Tg inali yotsika kuposa 0℃, ndipo malo osungunuka anali otsika (38 ~ 48℃), ndipo mphamvu ndi zizindikiro zina zinali zovuta kukwaniritsa zosowa zogwiritsidwa ntchito. Gulu lofufuza la Zhao Jingbo linagwiritsa ntchito ethylene carbonate, 1, 6-hexanediamine ndi polyethylene glycol popanga PEU, yomwe ili ndi kulemera kwa molekyulu ya 31 000g/mol, mphamvu yolimba ya 5 ~ 24MPa, ndi kutalika pakagwa 0.9% ~ 1 388%. Kulemera kwa mamolekyu a polyurethanes opangidwa ndi aromatic ndi 17 300 ~ 21 000g/mol, Tg ndi -19 ~ 10℃, malo osungunuka ndi 102 ~ 110℃, mphamvu yokoka ndi 12 ~ 38MPa, ndipo kuchuluka kwa kuchira kwa elasticity kwa 200% constant elongation ndi 69% ~ 89%.
Gulu lofufuza la Zheng Liuchun ndi Li Chuncheng linakonza 1, 6-hexamethylenediamine (BHC) yapakati yokhala ndi dimethyl carbonate ndi 1, 6-hexamethylenediamine, ndi polycondensation yokhala ndi mamolekyulu ang'onoang'ono osiyanasiyana okhala ndi ma diols olunjika ndi polytetrahydrofuranediols (Mn=2 000). Mndandanda wa polyether polyurethanes (NIPEU) wokhala ndi njira yosakhala isocyanate unakonzedwa, ndipo vuto lolumikizana la ma intermediates panthawi ya reaction linathetsedwa. Kapangidwe ndi katundu wa polyether polyurethane (HDIPU) yachikhalidwe yokonzedwa ndi NIPEU ndi 1, 6-hexamethylene diisocyanate zinayerekezeredwa, monga momwe zasonyezedwera mu Table 1.
| Chitsanzo | Gawo lolimba la kulemera kwa gawo/% | Kulemera kwa maselo/(g)·mol^(-1)) | Chizindikiro cha kugawa kulemera kwa maselo | Mphamvu yokoka/MPa | Kutalika kwa nthawi yopuma/% |
| NIPEU30 | 30 | 74000 | 1.9 | 12.5 | 1250 |
| NIPEU40 | 40 | 66000 | 2.2 | 8.0 | 550 |
| HDIPU30 | 30 | 46000 | 1.9 | 31.3 | 1440 |
| HDIPU40 | 40 | 54000 | 2.0 | 25.8 | 1360 |
Gome 1
Zotsatira zomwe zili mu Table 1 zikusonyeza kuti kusiyana kwa kapangidwe kake pakati pa NIPEU ndi HDIPU makamaka kumachitika chifukwa cha gawo lolimba. Gulu la urea lomwe limapangidwa ndi NIPEU limalowa mwachisawawa mu unyolo wa molekyulu wa gawo lolimba, ndikuswa gawo lolimba kuti lipange ma hydrogen bonds okonzedwa, zomwe zimapangitsa kuti ma hydrogen bonds ofooka pakati pa ma molecule chains a gawo lolimba ndi crystallinity yochepa ya gawo lolimba, zomwe zimapangitsa kuti NIPEU isiyane pang'ono. Zotsatira zake, mawonekedwe ake amakaniko ndi oyipa kwambiri kuposa HDIPU.
2.2 Polyurethane
Polyester polyurethane (PETU) yokhala ndi ma diol a polyester ngati zigawo zofewa ili ndi mphamvu yabwino yowola, yogwirizana ndi chilengedwe komanso yamakina, ndipo ingagwiritsidwe ntchito kukonza ma scaffolds opangira minofu, yomwe ndi chinthu chamankhwala chomwe chingagwiritsidwe ntchito bwino. Ma diol a polyester omwe amagwiritsidwa ntchito kwambiri m'zigawo zofewa ndi polybutylene adipate diol, polyglycol adipate diol ndi polycaprolactone diol.
Poyamba, Rokicki ndi anzake adapanga ethylene carbonate ndi diamine ndi ma diol osiyanasiyana (1, 6-hexanediol,1, 10-n-dodecanol) kuti apeze NIPU yosiyana, koma NIPU yopangidwayo inali ndi kulemera kochepa kwa mamolekyulu ndi Tg yotsika. Farhadian ndi anzake adapanga polycyclic carbonate pogwiritsa ntchito mafuta a mbewu ya mpendadzuwa ngati zinthu zopangira, kenako adasakaniza ndi ma polyamines okhala ndi bio, ataphimbidwa pa mbale, ndikuchiritsidwa pa 90 ℃ kwa maola 24 kuti apeze filimu ya polyester polyurethane yotenthetsera, yomwe idawonetsa kukhazikika kwabwino kwa kutentha. Gulu lofufuza la Zhang Liqun kuchokera ku South China University of Technology lidapanga ma diamines angapo ndi ma cyclic carbonates, kenako adapanga dibasic acid yokhala ndi biobased kuti apeze polyester polyurethane yokhala ndi biobased. Gulu lofufuza la Zhu Jin ku Ningbo Institute of Materials Research, Chinese Academy of Sciences lidakonza gawo lolimba la diaminodiol pogwiritsa ntchito hexadiamine ndi vinyl carbonate, kenako polycondensation yokhala ndi unsaturated dibasic acid yokhala ndi bio-based kuti apeze polyester polyurethane, yomwe ingagwiritsidwe ntchito ngati utoto pambuyo pa ultraviolet criteria [23]. Gulu lofufuza la Zheng Liuchun ndi Li Chuncheng linagwiritsa ntchito adipic acid ndi ma aliphatic diol anayi (butanediol, hexadiol, octanediol ndi decanediol) okhala ndi manambala osiyanasiyana a atomu ya kaboni kuti akonze ma polyester diol ofanana ngati magawo ofewa; Gulu la non-isocyanate polyester polyurethane (PETU), lotchedwa chiwerengero cha ma atomu a kaboni a ma aliphatic diol, linapezeka posungunuka polycondensation ndi hydroxy-sealed hard segment prepolymer yokonzedwa ndi BHC ndi ma diol. Kapangidwe ka makina a PETU kakuwonetsedwa mu Table 2.
| Chitsanzo | Mphamvu yokoka/MPa | Modulus yotanuka/MPa | Kutalika kwa nthawi yopuma/% |
| PETU4 | 6.9±1.0 | 36±8 | 673±35 |
| PETU6 | 10.1±1.0 | 55±4 | 568±32 |
| PETU8 | 9.0±0.8 | 47±4 | 551±25 |
| PETU10 | 8.8±0.1 | 52±5 | 137±23 |
Gome 2
Zotsatira zake zikusonyeza kuti gawo lofewa la PETU4 lili ndi kuchuluka kwakukulu kwa carbonyl, mgwirizano wamphamvu kwambiri wa hydrogen ndi gawo lolimba, komanso digiri yotsika kwambiri yolekanitsa magawo. Kupangika kwa makristalo a magawo ofewa ndi olimba ndi kochepa, kuwonetsa malo otsika osungunuka ndi mphamvu yokoka, koma kutalika kwakukulu kwambiri pakusweka.
2.3 Polycarbonate polyurethane
Polycarbonate polyurethane (PCU), makamaka aliphatic PCU, ili ndi kukana kwabwino kwa hydrolysis, kukana okosijeni, kukhazikika kwabwino kwa zamoyo komanso kuyanjana kwa zamoyo, ndipo ili ndi mwayi wabwino wogwiritsa ntchito m'munda wa biomedicine. Pakadali pano, NIPU yambiri yokonzedwa imagwiritsa ntchito polyether polyols ndi polyester polyols ngati magawo ofewa, ndipo pali malipoti ochepa ofufuza pa polycarbonate polyurethane.
Polyurethane ya polycarbonate yopanda isocyanate yokonzedwa ndi gulu lofufuza la Tian Hengshui ku South China University of Technology ili ndi kulemera kwa molekyulu kopitilira 50 000 g/mol. Mphamvu ya zochitika pa kulemera kwa molekyulu ya polima yaphunziridwa, koma makhalidwe ake a makina sananenedwe. Gulu lofufuza la Zheng Liuchun ndi Li Chuncheng linakonza PCU pogwiritsa ntchito DMC, hexanediamine, hexadiol ndi polycarbonate diols, ndipo linatcha PCU malinga ndi gawo la unit yobwerezabwereza ya hard segment. Makhalidwe a makina akuwonetsedwa mu Table 3.
| Chitsanzo | Mphamvu yokoka/MPa | Modulus yotanuka/MPa | Kutalika kwa nthawi yopuma/% |
| PCU18 | 17±1 | 36±8 | 665±24 |
| PCU33 | 19±1 | 107±9 | 656±33 |
| PCU46 | 21±1 | 150±16 | 407±23 |
| PCU57 | 22±2 | 210±17 | 262±27 |
| PCU67 | 27±2 | 400±13 | 63±5 |
| PCU82 | 29±1 | 518±34 | 26±5 |
Gome 3
Zotsatira zake zikusonyeza kuti PCU ili ndi kulemera kwakukulu kwa mamolekyulu, mpaka 6 × 104 ~ 9 × 104g/mol, malo osungunuka mpaka 137 ℃, ndi mphamvu yolimba mpaka 29 MPa. Mtundu uwu wa PCU ungagwiritsidwe ntchito ngati pulasitiki yolimba kapena ngati elastomer, yomwe ili ndi mwayi wabwino wogwiritsidwa ntchito m'munda wa zamankhwala (monga ma scaffolds a uinjiniya wa minofu ya anthu kapena zinthu zoyikira mtima).
2.4 Polyurethane yosakanizidwa yopanda isocyanate
Hybrid non-isocyanate polyurethane (hybrid NIPU) ndi kuyika magulu a epoxy resin, acrylate, silica kapena siloxane mu chimango cha polyurethane molecular kuti apange netiweki yolumikizirana, kukonza magwiridwe antchito a polyurethane kapena kupatsa polyurethane ntchito zosiyanasiyana.
Feng Yuelan ndi anzake adapanga mafuta a soya a epoxy okhala ndi bio ndi CO2 kuti apange pentamonic cyclic carbonate (CSBO), ndipo adayambitsa bisphenol A diglycidyl ether (epoxy resin E51) yokhala ndi zigawo zolimba kwambiri za unyolo kuti apititse patsogolo NIPU yopangidwa ndi CSBO yokhazikika ndi amine. Unyolo wa molekyulu uli ndi gawo lalitali la unyolo wosinthasintha wa oleic acid/linoleic acid. Ulinso ndi zigawo zolimba kwambiri za unyolo, kotero kuti uli ndi mphamvu yayikulu yamakina komanso kulimba kwambiri. Ofufuza ena adapanganso mitundu itatu ya ma prepolymer a NIPU okhala ndi magulu a furan end kudzera mu reaction yotsegulira liwiro la diethylene glycol bicyclic carbonate ndi diamine, kenako adapanganso ndi polyester yosakhuta kuti akonze polyurethane yofewa yokhala ndi ntchito yodzichiritsa yokha, ndipo adazindikira bwino luso lalikulu la kudzichiritsa lokha la NIPU yofewa. NIPU yosakanikirana sikuti imangokhala ndi makhalidwe a NIPU wamba, komanso ingakhale ndi kumatira bwino, kukana asidi ndi dzimbiri la alkali, kukana zosungunulira komanso mphamvu yamakina.
3 Chiyembekezo
NIPU imakonzedwa popanda kugwiritsa ntchito isocyanate ya poizoni, ndipo pakadali pano ikuphunziridwa mu mawonekedwe a thovu, zokutira, zomatira, elastomer ndi zinthu zina, ndipo ili ndi mitundu yosiyanasiyana ya njira zogwiritsira ntchito. Komabe, zambiri mwa izo zimangokhala kafukufuku wa labotale, ndipo palibe kupanga kwakukulu. Kuphatikiza apo, ndi kusintha kwa miyezo ya moyo wa anthu komanso kukula kosalekeza kwa kufunikira, NIPU yokhala ndi ntchito imodzi kapena zingapo yakhala njira yofunika kwambiri yofufuzira, monga antibacterial, kudzikonza yokha, kukumbukira mawonekedwe, kuletsa moto, kukana kutentha kwambiri ndi zina zotero. Chifukwa chake, kafukufuku wamtsogolo ayenera kumvetsetsa momwe angadutse mavuto ofunikira a mafakitale ndikupitiliza kufufuza njira yokonzekera NIPU yogwira ntchito.
Nthawi yotumizira: Ogasiti-29-2024