Aha ngwaahịa:polyurethane

Ọdịdị molekụla ngwaahịa:

Njirimara kemịkalụ:

Ọ bụ Dr. Otto Bayer bụ nke mbụ mepụtara ma nyochaa polyurethane na 1937. Polyurethane bụ polymer nke ihe na-emeghachi ihe na-agụnye ihe ndị na-emepụta urethane.Urethanes bụ ihe nrụpụta nke carbamic acid nke dị naanị n'ụdị esters ha[15].Isi uru dị na PU bụ na yinye abụghị naanị carbon carbon mejupụtara kama ọ bụ heteroatoms, oxygen, carbon na nitrogen[4].Maka ngwa ụlọ ọrụ mmepụta ihe, a pụrụ iji ogige polyhydroxyl mee ihe.N'otu aka ahụ, enwere ike iji ogige nitrogen arụ ọrụ na-arụ ọrụ na njikọ amide.Site n'ịgbanwe ma gbanwee polyhydroxyl na polyfunctional nitrogen ogige, PU dị iche iche nwere ike ịmepụta [15].A na-eji resin polyester ma ọ bụ polyether nwere otu hydroxyl na-emepụta polyesteror polyether-PU, n'otu n'otu[6].Ọdịiche dị na ọnụọgụ ngbanwe na oghere dị n'etiti na n'ime ụdọ alaka ụlọ ọrụ na-emepụta PU sitere na linear ruo alaka na 9exible ruo siri ike.A na-eji PU Linear eme ihe maka imepụta eriri na ịkpụzi[6].A na-eji PU na-agbanwe agbanwe na-emepụta ihe na-ejikọta ya na mkpuchi[5].Plastic foamed na-agbanwe agbanwe na nke siri ike, nke mejupụtara ọtụtụ PU ndị emepụtara, nwere ike ịhụ n'ụdị dị iche iche na ụlọ ọrụ[7].N'iji prepolymers dị ala molecular mass, enwere ike ịmepụta copolymers dị iche iche.Otu ọnụ hydroxyl na-enye ohere ka etinye ihe mgbochi ọzọ, nke a na-akpọ ngalaba, n'ime agbụ PU.Mgbanwe dị na ngalaba ndị a na-ebute ogo dị iche iche nke ike ike na nkwụ.A na-akpọ ihe mgbochi na-enye usoro kristal siri ike yana nke nwere eriri ndọtị dị ka akụkụ siri ike[7].Ndị na-enye usoro rubbery amorphous nwere polyester/polyether ka a na-akpọ akụkụ dị nro.Azụmahịa, a na-akpọ polymers ngọngọ ndị a dị ka Pus nke kewara ekewa

Ngwa:

Polyurethane bụ otu n'ime ihe ndị kachasị mma n'ụwa taa.Ọtụtụ ojiji ha sitere na ụfụfụ na-agbanwe agbanwe na arịa ụlọ elu, ruo ụfụfụ siri ike dị ka mkpuchi na mgbidi, elu ụlọ na ngwa na polyurethane thermoplastic eji na ngwaọrụ ahụike na akpụkpọ ụkwụ, na mkpuchi, nrapado, sealants na elastomers eji n'ala na ime ụgbọ ala [17,18] ].A na-eji polyurethanes eme ihe n'ime afọ iri atọ gara aga na ngwa dị iche iche n'ihi nkasi obi ha, uru ọnụ ahịa, nchekwa ike na ike gburugburu ebe obibi.Kedu ihe ụfọdụ na-eme ka polyurethane dị mma?Ịdị ogologo nke polyurethane na-enye aka nke ukwuu na ogologo ndụ nke ọtụtụ ngwaahịa.Mgbakwunye nke usoro ndụ ngwaahịa na nchekwa ihe onwunwe bụ ihe dị mkpa gburugburu ebe obibi na-akwadokarị nhọrọ nke polyurethane[19-21].Polyurethanes (PUs) na-anọchi anya klaasị dị mkpa nke thermoplastic na thermoset polymers dị ka igwe ha, thermal, na kemịkalụ nwere ike ahaziri site na mmeghachi omume nke polyols dị iche iche na poly-isocyanates.