Inoa mea kūʻai:polyurethane

Huahana molecular structure:

Nā waiwai kemika:

Ua hana mua ʻia ka polyurethanes a ua noiʻi ʻia e Kauka Otto Bayer i ka makahiki 1937. ʻO ka polyurethane kahi polymer i loaʻa i ka ʻāpana hana hou kahi ʻāpana urethane.ʻO nā Urethanes nā mea i loaʻa i nā waikawa carbamic e noho wale ana ma ke ʻano o kā lākou esters[15].ʻO ka pōmaikaʻi nui o ka PU ʻo ia ʻaʻole i haku wale ʻia ke kaulahao o nā kalapona kalapona akā ʻo nā heteroatoms, oxygen, carbon a me ka nitrogen [4].No nā hana ʻoihana, hiki ke hoʻohana ʻia kahi pūhui polyhydroxyl.Pēlā nō, hiki ke hoʻohana ʻia nā pūhui nitrogen poly-functional ma nā loulou amide.Ma ka hoʻololi ʻana a me ka hoʻololi ʻana i ka polyhydroxyl a me ka polyfunctional nitrogen compound, hiki ke hoʻohui ʻia nā PU like ʻole [15].Hoʻohana ʻia nā resins polyester a i ʻole polyether i loaʻa nā hui hydroxyl e hana i ka polyesteror polyether-PU, kēlā me kēia [6].ʻO nā ʻano like ʻole o ka helu o nā pani a me ka spacing ma waena a ma loko o nā kaulahao lālā e hoʻopuka ai i nā PU mai ka laina laina a i ka lālā a 9exible a i ʻole.Hoʻohana ʻia nā PU Linear no ka hana ʻana i nā fibers a me ka hoʻoheheʻe ʻana [6].Hoʻohana ʻia nā PU maʻalahi i ka hana ʻana i nā mea paʻa a me nā uhi [5].Hiki ke loaʻa i nā ʻano like ʻole o ka ʻoihana i nā ʻano like ʻole o nā PU i hana ʻia.Me ka hoʻohana ʻana i nā prepolymers nuipa haʻahaʻa haʻahaʻa, hiki ke hana ʻia nā ʻano copolymers poloka.Hiki i ka hui hydroxyl terminal ke hoʻokomo ʻia i loko o ke kaulahao PU.ʻO ka hoʻololi ʻana i kēia mau ʻāpana e hopena i nā pae like ʻole o ka ikaika tensile a me ka elasticity.ʻO nā poloka e hāʻawi ana i ka māhele crystalline paʻa a loaʻa ka mea hoʻonui kaulahao i kapa ʻia he mau ʻāpana paʻakikī [7].ʻO ka poʻe e hāʻawi ana i kahi ʻāpana rubbery amorphous a loaʻa ka polyester/polyether i kapa ʻia nā ʻāpana palupalu.Ma ke kālepa, ʻike ʻia kēia mau polimer poloka ʻo Pus ʻāpana

Noi:

ʻO nā polyurethanes kekahi o nā mea maʻalahi loa o ka honua i kēia lā.ʻO kā lākou hoʻohana nui ʻana mai ka ʻūhū maʻalahi i loko o nā mea i hoʻopaʻa ʻia, i ka ʻōpala paʻa e like me ka insulation i nā paia, nā hale a me nā mea hana i ka polyurethane thermoplastic i hoʻohana ʻia i nā lāʻau lapaʻau a me nā kāmaʻa, i nā uhi, adhesives, sealants a me nā elastomers i hoʻohana ʻia ma nā papahele a me nā kaʻa kaʻa [17,18]. ].Ua hoʻohana nui ʻia ka polyurethanes i nā makahiki he kanakolu i hala iho nei i nā ʻano noi like ʻole ma muli o ko lākou hōʻoluʻolu, nā uku kumukūʻai, ka mālama ʻana i ka ikehu a me ka maikaʻi o ke kaiapuni.He aha kekahi mau mea e makemake nui ai ka polyurethanes?Hāʻawi nui ka polyurethane durability i ka lōʻihi o ke ola o nā huahana he nui.ʻO ka hoʻonui ʻia ʻana o ke ola o ka huahana a me ka mālama ʻana i nā kumuwaiwai he mea koʻikoʻi ka noʻonoʻo kaiapuni e makemake pinepine i ke koho ʻana i nā polyurethanes[19-21].Hōʻike nā Polyurethanes (PU) i kahi papa koʻikoʻi o nā polymers thermoplastic a me nā thermoset no ka mea hiki ke hoʻopili ʻia ko lākou mau mea mechanical, thermal, a me nā mea kemika e ka hopena o nā polyols a me nā poly-isocyanates.