Lebitso la Sehlahiswa:polyurethane

Sebopeho sa limolek'hule tsa sehlahisoa:

Lintho tsa Lik'hemik'hale:

Li-polyurethanes li ile tsa hlahisoa ka lekhetlo la pele 'me tsa batlisisoa ke Dr. Otto Bayer ka 1937. Polyurethane ke polymer eo karolo e pheta-phetoang e nang le karolo ea urethane.Li-urethane li tsoa ho li-carbamic acid tse teng feela ka sebopeho sa li-ester tsa tsona[15].Monyetla o moholo oa PU ke hore ketane ha e entsoe feela ka liathomo tsa khabone empa e entsoe ka li-heteroatom, oksijene, khabone le naetrojene[4].Bakeng sa lits'ebetso tsa indasteri, motsoako oa polyhydroxyl o ka sebelisoa.Ka mokhoa o ts'oanang, metsoako ea naetrojene e sebetsang ka bongata e ka sebelisoa likhokahanong tsa amide.Ka ho fetola le ho fetola metsoako ea polyhydroxyl le polyfunctional nitrogen, li-PU tse fapaneng li ka etsoa [15].Li-resin tsa polyester kapa polyether tse nang le lihlopha tsa hydroxyl li sebelisoa ho hlahisa polyesteror polyether-PU, ka ho latellana[6].Phapang ea palo ea li-substitutes le sebaka pakeng tsa liketane tsa makala le ka hare ho makala li hlahisa li-PU ho tloha ho linear ho ea ho branched le 9exible ho ea thata.Linear PUs e sebelisetsoa ho etsa likhoele le ho bopa[6].Flexible PUs e sebelisoa tlhahisong ea li-agent tse tlamang le liphahlo[5].Lipolasetiki tse tenyetsehang le tse thata, tse etsang boholo ba li-PU tse hlahisoang, li ka fumaneha ka mefuta e fapaneng indastering[7].Ho sebelisa li-prepolymers tse tlase tsa molek'hule, li-copolymers tse fapaneng li ka hlahisoa.Sehlopha sa terminal sa hydroxyl se lumella li-blocks tse fapaneng, tse bitsoang likarolo, hore li kenngoe ketane ea PU.Ho fapana ha likarolo tsena ho etsa hore ho be le maemo a sa tšoaneng a matla le elasticity.Li-blocks tse fanang ka karolo e thata ea kristale le tse nang le ketane extender li bitsoa likarolo tse thata[7].Tse hlahisang karolo ea rabara ea amorphous 'me e nang le polyester / polyether li bitsoa likarolo tse bonolo.Khoebong, li-polymer tsena tsa block li tsejoa e le Segmented Pus

Kopo:

Polyurethanes ke e 'ngoe ea lisebelisoa tse sebetsang ka ho fetisisa lefatšeng kajeno.Tšebeliso ea bona e mengata e tloha ho foam e tenyetsehang ka thepa ea ka tlung, ho ea ho foam e thata e le ho pata maboteng, marulelong le lisebelisoa ho thermoplastic polyurethane e sebelisoang lisebelisoa tsa bongaka le lieta, ho koahela, li-adhesives, sealants le elastomers tse sebelisoang fatše le ka hare ho likoloi [17,18]. ].Li-polyurethanes li 'nile tsa sebelisoa ka ho eketsehileng nakong ea lilemo tse mashome a mararo tse fetileng ka mefuta e sa tšoaneng ea lisebelisoa ka lebaka la boiketlo ba tsona, melemo ea litšenyehelo, ho boloka matla le ho utloahala ha tikoloho.Ke lintlha life tse ling tse etsang hore polyurethane e lakatsehe hakaale?Ho tšoarella ha polyurethane ho kenya letsoho haholo bophelong bo bolelele ba lihlahisoa tse ngata.Katoloso ea potoloho ea bophelo ba sehlahisoa le paballo ea lisebelisoa ke lintlha tsa bohlokoa tsa tikoloho tseo hangata li ratang khetho ea polyurethanes[19-21].Polyurethanes (PUs) e emela sehlopha sa bohlokoa sa li-polymer tsa thermoplastic le thermoset kaha thepa ea bona ea mochini, e futhumatsang le ea lik'hemik'hale e ka hlophisoa ke karabelo ea li-polyol tse fapaneng le poly-isocyanate.