ʻO ka polyethylene haʻahaʻa haʻahaʻa (LDPE) kahi thermoplastic i hana ʻia mai ka monomer ethylene.ʻO ia ka papa mua o ka polyethylene, i hana ʻia ma 1933 e Imperial Chemical Industries (ICI) me ka hoʻohana ʻana i kahi kaʻina hana kiʻekiʻe ma o ka polymerization radical manuahi.Manaʻo ka EPA he 5.7% o ka LDPE i hana hou ʻia.ʻOiai ka hoʻokūkū mai nā polymers hou aʻe, ke hoʻomau nei ʻo LDPE i kahi papa plastik koʻikoʻi.
Ua wehewehe ʻia ʻo LDPE e kahi ākea ākea o 0.910–0.940 g/cm3.ʻAʻole ia e hoʻoulu i nā mahana lumi, koe wale nō me nā mea hoʻoheheʻe ikaika, a ʻo kekahi mau solvents ke kumu i ka pehu.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.
ʻOi aku ka lālā o LDPE ma mua o HDPE, no laila ʻoi aku ka nāwaliwali o kona mau intermolecular ikaika, haʻahaʻa kona ikaika tensile, a ʻoi aku ka kiʻekiʻe o kona kūpaʻa.Eia kekahi, no ka mea, ʻaʻole i paʻa paʻa kona mau molekala a emi ʻole ka crystalline ma muli o nā lālā ʻaoʻao, ʻoi aku ka haʻahaʻa.
ʻO ka PTFE he polymer thermoplastic, he paʻa keʻokeʻo ma ka lumi wela, me ka nui o 2200 kg / m3.Wahi a DuPont, ʻo kona wahi heheʻe he 600 K (327 °C; 620 °F).[19]Mālama ʻo ia i ka ikaika kiʻekiʻe, paʻakikī a me ka lubrication ponoʻī ma nā haʻahaʻa haʻahaʻa a hiki i 5 K (−268.15 °C; −450.67 °F), a me ka hoʻololi maikaʻi i nā mahana ma luna o 194 K (−79 °C; −110 °F).Loaʻa ka PTFE i kāna mau waiwai mai ka hopena aggregate o nā kaula kalapona-fluorine, e like me nā fluorocarbons a pau.ʻO nā kemika wale nō i ʻike ʻia e pili ana i kēia mau mea paʻa kalapona-fluorine he mau metala reactive loa e like me nā metala alkali, a ma nā mahana kiʻekiʻe e like me nā metala e like me ka aluminika a me ka magnesium, a me nā mea hana fluorinating e like me xenon difluoride a me cobalt(III) fluoride.
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Nā noi mea waiwai:
PTFE:ʻO nā mea hoʻonā kelepona; ʻAʻole lubricated bearings; O-rings; Sila; Capacitors; Hana semiconductor; Nā ʻāpana uila wela kiʻekiʻe; Gaskets; Nā ʻāpana valve.
LDPE:ʻO nā pā a me nā pahu hana maʻamau; Nā ʻaoʻao hana pale-corrosion; Nā ʻāpana o nā lako kamepiula, e like me nā disk drive, nā kāleka pale, a me nā disk drive optical.
Mea Pono
PTFE:ʻO nā waiwai dielectric maikaʻi loa; ʻAʻole i ka hapa nui o nā mea kemika; ʻO ka wela kiʻekiʻe a me ke kūpaʻa kemika; Haʻahaʻa haʻahaʻa haʻahaʻa o ka friction; ʻOi aku ka maikaʻi o ka pale ʻana i ka radiation; Zero moisture absorption; Pili ʻole i ka mana pinepine; Machinability.
LDPE:Non-reactive i ka lumi wela; Hiki ke pale i nā mahana o 80 ° C mau; Machinability.
Ka manawa hoʻouna: Nov-01-2017