Dzina la malonda:polyurethane

Kapangidwe kazinthu zama cell:

Chemical Properties:

Ma polyurethanes adapangidwa koyamba ndikufufuzidwa ndi Dr. Otto Bayer mu 1937. Polyurethane ndi polima momwe gawo lobwereza limakhala ndi urethane moiety. Urethanes ndi zotumphukira za ma carbamic acid omwe amapezeka mwa mawonekedwe a esters awo[15]. Ubwino waukulu wa PU ndikuti unyolowu supangidwa ndi maatomu a kaboni okha koma m'malo mwa ma heteroatomu, oxygen, carbon ndi nitrogen[4]. Pogwiritsa ntchito mafakitale, polyhydroxyl pawiri ingagwiritsidwe ntchito. Mofananamo, mankhwala a nayitrogeni a poly-functional atha kugwiritsidwa ntchito polumikizana ndi amide. Posintha ndikusintha ma polyhydroxyl ndi polyfunctional nitrogen compounds, ma PU osiyanasiyana amatha kupangidwa [15]. Ma polyester kapena polyether resins okhala ndi magulu a hydroxyl amagwiritsidwa ntchito kupanga polyesteror polyether-PU, motsatana [6]. Kusiyanasiyana kwa kuchuluka kwa zolowa m'malo ndi kagawidwe pakati ndi mkati mwa unyolo wanthambi kumatulutsa ma PU kuyambira mzere mpaka nthambi ndi 9exible mpaka olimba. Linear PUs amagwiritsidwa ntchito popanga ulusi ndi kuumba[6]. Flexible PUs amagwiritsidwa ntchito popanga zomangira ndi zokutira[5]. Mapulasitiki osinthika komanso olimba a thovu, omwe amapanga ma PU ambiri opangidwa, amapezeka m'njira zosiyanasiyana m'makampani[7]. Pogwiritsa ntchito ma prepolymer otsika a cell, ma copolymer osiyanasiyana amatha kupangidwa. Gulu la terminal la hydroxyl limalola kuti midadada yosinthira, yotchedwa magawo, kuti ayikidwe mu unyolo wa PU. Kusiyanasiyana m'magawo awa kumabweretsa milingo yosiyanasiyana yamphamvu yamphamvu komanso kukhazikika. Midawu yopereka gawo lolimba la crystalline komanso yokhala ndi chain extender imatchedwa magawo olimba[7]. Zomwe zimapatsa gawo la amorphous rubbery ndipo zimakhala ndi polyester / polyether amatchedwa zigawo zofewa. Pazamalonda, ma polima a block awa amadziwika kuti Segmented Pus

Ntchito:

Flexible polyurethane makamaka ndi liniya kapangidwe ndi thermoplasticity, amene ali bwino bata, kukana mankhwala, kulimba mtima ndi mawotchi katundu kuposa PVC thovu, ndi zochepa psinjika kusiyana. Ili ndi kutsekemera kwabwino kwamafuta, kutsekereza mawu, kukana kugwedezeka komanso anti-toxic properties. Chifukwa chake, imagwiritsidwa ntchito ngati kuyika, kutsekereza mawu ndi zida zosefera. Pulasitiki yolimba ya polyurethane ndi yopepuka, yotsekereza mawu, kutchinjiriza kwapamwamba kwambiri, kukana mankhwala, mphamvu zamagetsi zamagetsi, kukonza kosavuta, komanso kuyamwa kwamadzi otsika. Amagwiritsidwa ntchito kwambiri ngati zida zomangira, magalimoto, makampani opanga ndege, kutchinjiriza kutentha komanso kutchinjiriza kwamafuta. Polyurethane elastomer ntchito pakati pulasitiki ndi mphira, mafuta kukana, kuvala kukana, otsika kutentha kukana, kukana kukalamba, mkulu kuuma, elasticity. Amagwiritsidwa ntchito makamaka m'makampani a nsapato ndi makampani azachipatala. Polyurethane imathanso kupangidwa kukhala zomatira, zokutira, zikopa zopangira, etc.