Kedu ihe bụ polyurethane na-agwọta mmiri

Kedu ihe bụ polyurethane na-agwọta mmiri

Polyurethane a gwọchara mmiri bụ otu akụkụ polyurethane na ọgwụgwọ ya bụ mmalite mmiri mmiri gburugburu. Polyurethane nke nwere ike ịgwọ mmiri bụ nke kachasị nke isocyyanate-akwụsị tupu-polymer. Enwere ike iji ụdị pre-polymer dị iche iche nye ihe onwunwe achọrọ. Dịka ọmụmaatụ, a na-eji polyether polyols nke isocyanate kwụsịrị iji nye mgbanwe dị mma n'ihi ọnọdụ mgbanwe iko ha dị ala. Ijikọta akụkụ dị nro, dị ka polyether, na akụkụ siri ike, dị ka polyurea, na-enye ezigbo ike na mgbanwe nke mkpuchi. Ọzọkwa, a na-achịkwa ihe ndị ahụ site na ịhọrọ ụdị isocyanates iji tinye na pre-polymer.

Ụdị isi abụọ nke isocyanates bụ aromatic isocyanate na aliphatic isocyanate. Isocyanate aromatic nwere mmeghachi omume dị elu. Otú ọ dị, ọ nwere adịghị ike mputa anwụ ngwa ngwa na oké discoloration. Ụfọdụ ihe atụ nke aromatic isocyanates bụ toluene diisocyanate(TDI) na 4,4'diphenylmethane diisocyanate(MDI). N'aka nke ọzọ, aliphatic isocyanate, dị ka, isophorone diisocyanate (IPDI), na-enye ọmarịcha ihu igwe na agba njide; ka o sina dị, mmeghachi omume nke aliphatic isocyanate dị ala, yabụ enwere ike ịchọ ụfọdụ ihe na-akpali akpali. Ya mere, ụdị isocyanate dị mkpa iji nweta ihe onwunwe na-achọsi ike. Ọzọkwa, enwere ike ịgbakwunye ihe mgbakwunye, ihe mgbaze, pigmenti, wdg dabere na ngwa. Otú ọ dị, a ghaghị ịchịkwa ihe ndị na-emepụta ihe maka polyurethane nke mmiri na-agwọ ka ọ bụrụ nke na-enweghị mmiri iji nweta ezigbo nkwụsi ike nchekwa na ihe nkiri ihe nkiri.

Ndị ọzọ uru nke polyurethane mmiri na-agwọta bụ na ọ bụ otu akụkụ. Ya mere, ọ dị mfe iji ebe ọ bụ na ọ dịghị nhazi ngwakọta kwesịrị ekwesị achọrọ, ma e jiri ya tụnyere mkpuchi ihe abụọ. A na-ejikọta PU mmiri na-agwọta mmiri site na mmeghachi omume nke Isocyanate-akwụsị tupu-polymer na mmiri na ikuku, na-emepụta amines na obere carbon dioxide. N'ikpeazụ, mmeghachi omume nke amines na ndị ọzọ nke isocyyanate-akwụsị tupu polymer na-ewere ọnọdụ nke, na-emepụta njikọ urea.