M'zaka zaposachedwa, zinthu za polyurethane zakhala zikudziwika kwambiri, monga mapanelo ozizira osungira opangidwa ndi Harbin Dong'an Building Sheets ku China, omwe amapangidwa ndi zida za polyurethane.
Nthawi zambiri, polyurethane imatha kugawidwa mu thermosetting ndi thermoplastic, ndipo imatha kupangidwa kukhala mapulasitiki a polyurethane (makamaka mapulasitiki a thovu), ulusi wa polyurethane (spandex), ndi polyurethane elastomers. Zida zambiri za polyurethane zimatchedwa thermosetting, monga zofewa, zolimba komanso zolimba za polyurethane thovu.
Kubwezeretsanso kwa polyurethane nthawi zambiri kumagwiritsa ntchito njira zobwezeretsanso thupi, chifukwa njirayi ndi yothandiza komanso yotsika mtengo. Makamaka, itha kugawidwa m'njira zitatu zobwezeretsanso:
Njirayi ndi njira yomwe imagwiritsidwa ntchito kwambiri pokonzanso zinthu. Chithovu chofewa cha polyurethane chimaphwanyidwa mu zidutswa zingapo za centimita ndi chopukusira, ndipo zomatira za polyurethane zopopera zimapopera mu chosakanizira. Zomatira zomwe zimagwiritsidwa ntchito nthawi zambiri zimakhala zosakanikirana ndi thovu la polyurethane kapena NCO yothetsedwa prepolymer kutengera polyphenyl polymethylene polyisocyanate (PAPI). Mukamagwiritsa ntchito zomatira za PAPI zomangira ndi kuumba, kusakanikirana kwa nthunzi kumatha kuyambitsidwanso. Pogwirizanitsa zinyalala za polyurethane, onjezerani 90% zinyalala za polyurethane ndi 10% zomatira, sakanizani mofanana, kapena yonjezerani utoto wina, ndiyeno yesetsani kusakaniza.
Ukadaulo wopanga zomangira sikuti umakhala ndi kusinthasintha kwakukulu, komanso umakhala ndi kusiyana kwakukulu pamakina opangira chomaliza. Njira yabwino kwambiri yobwezeretsanso zinthu zopangidwa ndi polyurethane ndikupanga thovu lopangidwanso ndi polyurethane pomanga thovu lotayirira monga zotsalira za thovu zofewa, zomwe zimagwiritsidwa ntchito makamaka ngati kuthandizira pamphasa, mphasa zamasewera, zida zotsekereza mawu ndi zinthu zina. Tinthu ting'onoting'ono tofewa tofewa komanso zomatira zimatha kupangidwa kukhala zinthu monga mapadi pansi pagalimoto pa kutentha kwina ndi kupanikizika; Pogwiritsa ntchito kuthamanga kwambiri ndi kutentha, zida zolimba monga nyumba zapampu zimatha kupangidwa.
Foam yolimba ya polyurethane ndi reaction jakisoni akamaumba (RIM) polyurethane elastomer amathanso kubwezerezedwanso ndi njira yomweyo. Kusakaniza zinyalala ndi isocyanate prepolymers kwa otentha kukanikiza kupanga, monga kupanga mabulaketi mapaipi kwa makina Kutentha mapaipi. | 2,Hot kukanikiza akamaumba Thermosetting polyurethane thovu lofewa ndi zinthu za RIM polyurethane zimakhala ndi zofewa zina zamafuta komanso mapulasitiki pa kutentha kwa 100-200 ℃. Pa kutentha kwambiri ndi kupanikizika, zinyalala za polyurethane zimatha kumangirizidwa wina ndi mzake popanda kugwiritsa ntchito zomatira. Kuti zinthu zobwezerezedwanso zikhale zofananira, nthawi zambiri zimakhala zofunikira kuphwanya zinyalala ndikutenthetsa ndikuzisindikiza kuti zikhale mawonekedwe.
Zomwe zimapangidwira zimatengera mtundu wa zinyalala za polyurethane ndi zomwe zidasinthidwanso. Mwachitsanzo, polyurethane zofewa thovu zinyalala akhoza otentha mbamuikha kwa mphindi zingapo pa kuthamanga kwa 1-30MPa ndi kutentha osiyanasiyana 100-220 ° C kubala absorbers mantha, mudGuards, ndi zigawo zina.
Njirayi yagwiritsidwa ntchito bwino pakubwezeretsanso zigawo zamagalimoto zamtundu wa RIM polyurethane. Mwachitsanzo, mapanelo a zitseko zamagalimoto ndi mapanelo a zida amatha kupangidwa ndi pafupifupi 6% RIM polyurethane ufa ndi 15% fiberglass. | 3,Amagwiritsidwa ntchito ngati filler The polyurethane thovu zofewa akhoza kusandulika particles zabwino ndi otsika kutentha kuphwanya kapena akupera ndondomeko, ndi kubalalitsidwa kwa particles wotero ndi anawonjezera kuti polyols kupanga polyurethane thovu kapena zinthu zina, amene osati akuchira zinyalala zipangizo polyurethane, komanso mogwira amachepetsa. mtengo wa mankhwala. Zomwe zili mu ufa wosweka mu MDI yochokera ku chithovu chozizira chokhazikika cha polyurethane ndizochepa 15%, ndipo 25% ya ufa wosweka ukhoza kuwonjezeredwa mu TDI yochokera ku thovu lochiritsidwa kwambiri.
Mmodzi ndondomeko ndi kuwonjezera chisanadze akanadulidwa zinyalala thovu zinyalala mu zofewa thovu polyether polyol, ndiyeno chonyowa pogaya mu mphero yabwino kupanga "zobwezerezedwanso polyol" osakaniza munali particles zabwino kupanga thovu zofewa.
Zinyalala za RIM polyurethane zitha kuphwanyidwa kukhala ufa, wothira zinthu zopangira, kenako nkupangidwa kukhala RIM elastomers. Pambuyo pophwanyidwa chithovu cha polyurethane cholimba komanso chithovu cha polyisocyanurate (PIR), chitha kugwiritsidwanso ntchito kuwonjezera 5% zobwezerezedwanso mwa kuphatikiza kupanga thovu lolimba. |
M'zaka zaposachedwapa, njira yatsopano yobwezeretsa mankhwala yatulukira
Gulu la University of Illinois lotsogozedwa ndi Pulofesa Steven Zimmerman lapanga njira yowonongera zinyalala za polyurethane ndikuzisintha kukhala zinthu zina zothandiza.
Wophunzira womaliza maphunziro Ephraim Morado akuyembekeza kugwiritsa ntchitonso ma polima kudzera mu njira zama mankhwala kuti athetse vuto la zinyalala za polyurethane. Komabe, polyurethane imakhala yokhazikika kwambiri ndipo imapangidwa kuchokera ku zigawo ziwiri zomwe zimakhala zovuta kuwola: isocyanates ndi polyols.
Ma polyols ndiye chinsinsi cha vutoli, chifukwa amachotsedwa mu petroleum ndipo sawonongeka mosavuta. Pofuna kupewa zovuta izi, gulu lofufuza lidatengera acetal acetal yosungunuka mosavuta komanso yosungunuka m'madzi. Zowonongeka zomwe zimapangidwa ndi kusungunula ma polima okhala ndi trichloroacetic acid ndi dichloromethane kutentha kwapakati zitha kugwiritsidwa ntchito popanga zida zatsopano. Monga umboni wa lingaliro, Morado imatha kusintha ma elastomer omwe amagwiritsidwa ntchito kwambiri pakuyika ndi zida zamagalimoto kukhala zomatira.
Komabe, drawback lalikulu la njira yatsopano yobwezeretsanso ndi mtengo komanso kawopsedwe ka zinthu zomwe zimagwiritsidwa ntchito pochita. Choncho, ochita kafukufuku panopa akuyesera kupeza njira yabwino komanso yotsika mtengo kuti akwaniritse njira yomweyo pogwiritsa ntchito zosungunulira zofatsa monga vinyo wosasa kuti awonongeke.
M'tsogolomu, nyumba ya Harbin Dong'anpepalas kampaniidzatsatiranso mwatcheru luso la makampani ndikupitirizabe kuyika ndalama zaukadaulo ndi ukadaulo woteteza chilengedwe, kupanga zatsopano kuti mapanelo a Dong'an a polyurethane akhale ochezeka komanso athanzi. Tikukhulupiriranso kuti mtsogolomu padzakhala njira zatsopano zotetezera zachilengedwe.
Nthawi yotumiza: Nov-09-2023