nūhou

He aha nā polyolefins?

ʻO nā polyolefins kahi ʻohana o polyethylene a me polypropylene thermoplastics.Hana ʻia lākou mai ka aila a me ke kinoea maoli e ke kaʻina o ka polymerization o ka ethylene a me ka propylene.ʻO kā lākou versatility ua lilo lākou i hoʻokahi o nā plastics kaulana loa i hoʻohana ʻia i kēia lā.

Nā waiwai o nā polyolefins

ʻEhā ʻano o nā polyolefins:

• LDPE (polyethylene haʻahaʻa haʻahaʻa): Ua wehewehe ʻia ʻo LDPE e kahi ākea ākea o 0.910–0.940 g/cm3.Hiki iā ia ke pale i nā mahana o 80 ° C mau a me 95 ° C no ka manawa pōkole.Hana ʻia i nā ʻano like ʻole translucent a i ʻole opaque, maʻalahi a paʻakikī.
• LLDPE (linear low-density polyethylene): he polyethylene linear nui, me ka nui o na lala pokole, hana mau ia e ka copolymerization o ka ethylene me na olefin kaulahao loihi.Loaʻa i ka LLDPE ka ikaika tensile kiʻekiʻe a me ka hopena kiʻekiʻe a me ke kūpaʻa puncture ma mua o LDPE.He mea maʻalahi a elongates ma lalo o ke kaumaha.Hiki ke hoʻohana ʻia e hana i nā kiʻi ʻoniʻoni lahilahi a maikaʻi ke kūʻē ʻana i nā kemika.Loaʻa iā ia nā waiwai uila maikaʻi.Eia naʻe, ʻaʻole maʻalahi ka hana ʻana e like me LDPE.
• HDPE (polyethylene kiʻekiʻe kiʻekiʻe): Ua ʻike ʻia ʻo HDPE no kona nui ikaika-a-density ratio.Hiki i ka nui o ka HDPE mai 0.93 a 0.97 g/cm3 a i ʻole 970 kg/m3.ʻOiai ʻoi aku ka kiʻekiʻe o ka mānoanoa o HDPE ma mua o ka polyethylene haʻahaʻa haʻahaʻa, ʻoi aku ka liʻiliʻi o ka HDPE, e hāʻawi ana i nā ikaika intermolecular ikaika a me ka ikaika tensile ma mua o LDPE.ʻOi aku ka paʻakikī a ʻoi aku ka opaque a hiki ke kū i nā wela kiʻekiʻe aʻe (120 °C no nā manawa pōkole).
• PP (polypropylene): Aia ka mānoanoa o PP ma waena o 0.895 a me 0.92 g/cm³.No laila, ʻo PP ka plastic commodity me ka haʻahaʻa haʻahaʻa.Ke hoʻohālikelike ʻia me ka polyethylene (PE) he ʻoi aku ka maikaʻi o nā waiwai mechanical a me ke kūpaʻa wela, akā ʻoi aku ka liʻiliʻi o ka pale kemika.He paʻakikī a maʻalahi hoʻi ka PP, ʻoi aku ka nui o ka copolymerised me ka ethylene.

Nā noi o nā polyolefins

ʻO nā ʻano kikoʻī o nā ʻano polyolefins e hāʻawi iā lākou iho i nā noi like ʻole, e like me:

• LDPE: paʻi kiʻiʻoniʻoni, ʻeke lawe ʻeke, kiʻiʻoniʻoni mahiʻai, uhi pahu pahu waiu, uhi kelepona uila, ʻeke ʻoihana kaumaha.
• LLDPE: kiʻi kiʻiʻoniʻoni, kiʻiʻoniʻoni hoʻopihapiha ʻenehana, nā ipu ʻili lahilahi, a me nā ʻeke kaumaha, waena a me nā ʻeke liʻiliʻi.
• HDPE: nā pahu a me nā pahu, nā ʻōmole (no nā huahana meaʻai, nā mea hoʻomaʻemaʻe, nā mea hoʻonaninani), nā pahu meaʻai, nā mea pāʻani, nā pahu petrol, nā ʻāpana ʻenehana a me nā kiʻiʻoniʻoni, nā paipu a me nā mea hale.
• PP: ʻO ka ʻeke meaʻai, me ka yoghurt, nā ipu margarine, nā mea ʻono a me nā mea ʻai meaʻai, nā ipu hōʻoia microwave, nā ʻūla kāpeti, nā lako kīhāpai, nā ʻeke lapaʻau a me nā mea hana, nā ukana, nā lako kīhini, a me nā paipu.