Magaca Alaabta:polyurethane

Qaab dhismeedka molecular ee alaabta:

Guryaha Kiimikada:

Polyurethane waxaa markii ugu horreysay soo saaray oo baaray Dr. Otto Bayer 1937. Polyurethane waa polymer kaas oo unugga soo noqnoqda uu ka kooban yahay unug kaadi mareen ah.Urethanes waa asiidhyada karbamic ee ka jira oo kaliya qaabka ester-kooda[15].Faa'iidada ugu weyn ee PU waa in silsiladdu aysan ka koobnayn atamka kaarboonka laakiin halkii ay ka samaysan tahay heteroatoms, oxygen, carbon iyo nitrogen[4].Codsiyada warshadaha, xarun polyhydroxyl ayaa loo isticmaali karaa.Sidoo kale, xeryahooda nitrogen poly-functional waxaa loo isticmaali karaa isku xirka amide.Beddelida iyo kala duwanaanshaha polyhydroxyl iyo xeryahooda nitrogen polyfunctional, PU-yada kala duwan ayaa la isku dhejin karaa[15].Polyester-ka ama caarada polyeter-ka ee ay ku jiraan kooxaha hydroxyl ayaa loo isticmaalaa si loo soo saaro polyesteror polyether-PU, siday u kala horreeyaan[6].Kala duwanaanshaha tirada beddelka iyo kala fogaanshaha u dhexeeya iyo gudaha silsiladaha laanta waxay soo saaraan PU-yo u dhexeeya toosan ilaa laamo iyo 9exable ilaa adag.PU-yada tooska ah waxaa loo isticmaalaa soo saarista fiilooyinka iyo qaabeynta[6].PU-yada dabacsan ayaa loo isticmaalaa soo saarista walxaha xidhxidhan iyo dahaarka[5].Balaastig dabacsan oo adag, kuwaas oo ka kooban inta badan PU-yada la soo saaro, waxaa laga heli karaa noocyo kala duwan oo warshadaha[7].Iyadoo la isticmaalayo prepolymer-mass molecular hoose, copolymers block oo kala duwan ayaa la soo saari karaa.Kooxda hydroxyl terminal waxay u oggolaanaysaa baloogyada beddelka ah, ee loo yaqaan qaybaha, in la geliyo silsiladda PU.Kala duwanaanshiyaha qaybahan ayaa keenaya heerar kala duwan oo ah xoogga jilicsanaanta iyo dabacsanaanta.Baloogyada bixiya weji crystalline adag oo ay ku jiraan silsiladaha fidiyaha ayaa loo tixraacaa qaybo adag[7].Kuwa soo saara wajiga caagga ah ee amorfiska ah oo ay ku jiraan polyester-ka waxaa loo yaqaannaa qaybo jilicsan.Ganacsi ahaan, polymer-yadan block-ka ah waxaa loo yaqaanaa malax-qaybsan

Codsiga:

Polyurethane waa mid ka mid ah walxaha ugu badan ee adduunka maanta jira.Adeegsigoodu wuxuu u dhexeeyaa xumbo dabacsan oo alaabta guriga ah, ilaa xumbo adag sida dahaarka gidaarada, saqafyada iyo qalabka ilaa polyurethane thermoplastic loo isticmaalo aaladaha caafimaadka iyo kabaha, dahaarka, xabagta, shaabada iyo elastomers loo isticmaalo sagxadaha iyo gudaha baabuurta[17,18] ].Polyurethane ayaa si sii kordheysa loo isticmaalay soddonkii sano ee la soo dhaafay codsiyo kala duwan sababtoo ah raaxaysigooda, faa'iidooyinka kharashka, kaydinta tamarta iyo deegaanka suurtagalka ah ee deegaanka.Maxay yihiin qaar ka mid ah arrimaha ka dhigaya polyurethane si aad loo jecel yahay?Adkeysiga poliurethane wuxuu si weyn uga qaybqaataa cimriga dheer ee alaabooyin badan.Kordhinta wareegga nolosha badeecada iyo ilaalinta kheyraadka ayaa ah tixgalin deegaan oo muhiim ah oo inta badan door bida doorashada polyurethane[19-21].Polyurethanes (PUs) waxay u taagan yihiin heerar muhiim ah oo kuleyliyaha kuleyliyaha ah iyo heerkulbeegyada sida makaankooda, kulaylka, iyo alaabada kiimikaad waxaa lagu habeyn karaa falcelinta polyols kala duwan iyo poly-isocyanates.