Kodi polyurethane ndi chiyani?Kodi ubwino ndi kuipa kwa zipangizo polyurethane ndi chiyani?

Chiyambireni kupanga mafakitale m'zaka za m'ma 1950, zida za polyurethane (ndiko kuti, ma polima apamwamba kwambiri okhala ndi magulu a carbamate mu unyolo waukulu wa macromolecules - NHCOO) adakula mwachangu.Poyerekeza ndi zida za rabara za polima, ili ndi mawonekedwe ake apadera.Itha kugwiritsa ntchito magulu osiyanasiyana ogwira ntchito ndi mitundu yosiyanasiyana yamagulu ogwira ntchito molingana ndi zofunikira zosiyanasiyana, ndikugwiritsa ntchito njira zosiyanasiyana zopangira kupanga zinthu za polyurethane zomwe zimakhala ndi magwiridwe antchito komanso mawonekedwe osiyanasiyana.

Palinso zida zomwe sizili m'gulu la mphira, monga mapulasitiki okhala ndi thovu, zinthu zapulasitiki zolimba, zokutira, ulusi wokhazikika wokhazikika, zikopa zopanga, zomatira, ndi zina zambiri.

Zida za polyurethane zimagwiritsidwa ntchito kwambiri m'magawo osiyanasiyana, mwachitsanzo, m'makampani opanga ndege, zinthu zake zolimba, zofewa ndi thovu zimakhala zopepuka kuposa zida zachitsulo (zofunika kwambiri pa ndege), zomwe zimagwiritsidwa ntchito makamaka muzovundikira injini za ndege, mabuleki othamanga, tinyanga. Zophimba, zodzaza matanki amafuta andege, makina ogwiritsira ntchito mafuta a carburetor buoys, ndi zina zambiri, komanso mafelemu othandizira osiyanasiyana ndi ma cushion okongoletsa mkati, komanso kutchinjiriza pantchito zoyendera.Mipando ya mipando, mipando ya m'nyumba, ngakhale matayala sasiyanitsidwa ndi zinthu za polyurethane, ndipo kupangidwa kwaposachedwa ndi kugwiritsa ntchito zinthu zopangira zinthu zowononga magalimoto kwadzetsa zambiri.

Ngakhale pali mitundu yambiri ya zinthu zopangidwa ndi polyurethane, gulu lake lazinthu silinanso: zinthu zosinthika za thovu, zolimba komanso zopangira elastomers.

Ngati mankhwala akamaumba zida ndi wosanganiza mphira polyurethane, nthawi zambiri olimba ndipo akhoza vulcanized ndi sulfure, peroxide ndi polyisocyanate, ndipo akhoza kupangidwa molingana ndi ndondomeko kupanga ndi chilinganizo cha mankhwala ochiritsira mphira.Pankhani ya thermoplastic elastomers, imatha kukonzedwa ndi jekeseni kapena kuponderezana.Pankhani ya pulasitiki ya polyurethane, imatha kupangidwa ndi tepi.

Kutengera kusinthika kwa thovu la polyurethane mwachitsanzo, njira yopangira nthawi zambiri imakhala ndi zigawo ziwiri zamadzimadzi zomwe zimapangidwira.Ndiko kuti, gulu limodzi ndilo loyamba losakanikirana la polyol polima ndi isocyanate, ndiyeno zomwe zili pamwambazi zimasakanizidwa ndi gulu lina, kuphatikizapo madzi, thovu, stabilizer, chothandizira ndi othandizira osiyanasiyana kuti apange organic aminoformaldehyde Ester.Pa nthawi yomweyo, reactants monga magulu urea ntchito anachita kupanga mpweya woipa, kumasula kuchuluka kwa kutentha, ndiyeno ntchito chothandizira kusintha thovu liwiro, ndipo potsiriza malizitsani yunifolomu thovu mankhwala.

Pakalipano, makampani opanga magalimoto akuyenda bwino nthawi zonse pankhani ya chitetezo, chitonthozo ndi kulimba, ndipo pali zofunika kwambiri kuti zikhale zolimba pansi pazigawo zogwira ntchito kwambiri za elastomer zowonongeka komanso zowonongeka.Mtundu watsopano wamagetsi owopsa opangidwa ndi thovu lofewa la polyurethane wawoneka m'misika yakunja, ndipo mawonekedwe ake akuthupi komanso amakina komanso kunyowa kwake ndikwabwinoko pang'ono kuposa zida zotayira mphira.