Polyethylene Synthesis Njira ndi Zosiyanasiyana
(1) Polyethylene Yotsika Kachulukidwe (LDPE)
Pamene kuchuluka kwa mpweya kapena peroxides kuwonjezeredwa monga oyambitsa ku ethylene yoyera, yoponderezedwa mpaka pafupifupi 202.6 kPa, ndi kutenthedwa kufika pafupifupi 200 ° C, ethylene imasungunuka kukhala polyethylene yoyera, waxy. Njirayi imatchedwa kuti njira yowonongeka kwambiri chifukwa cha zochitika zogwirira ntchito. Polyethylene yomwe imachokera imakhala ndi kachulukidwe ka 0.915-0.930 g/cm³ ndi kulemera kwa maselo kuyambira 15,000 mpaka 40,000. Mapangidwe ake a mamolekyu ali ndi nthambi zambiri komanso zotayirira, zomwe zimafanana ndi "mtengo wofanana ndi mtengo", womwe umakhala wochepa kwambiri, choncho amatchedwa polyethylene yotsika kwambiri.
(2) Polyethylene yapakati-pakatikati (MDPE)
Njira yopatsirana yapakatikati imaphatikizapo polymerizing ethylene pansi pa 30-100 atmospheres pogwiritsa ntchito zopangira zitsulo za oxide. The chifukwa polyethylene ali ndi kachulukidwe wa 0.931-0.940 g/cm³. MDPE itha kupangidwanso pophatikiza polyethylene yapamwamba kwambiri (HDPE) ndi LDPE kapena kudzera mu copolymerization ya ethylene yokhala ndi zinthu zina monga butene, vinyl acetate, kapena acrylates.
(3) Polyethylene Yapamwamba Kwambiri (HDPE)
Pa kutentha kwabwino komanso kupanikizika, ethylene imapangidwa ndi polymerized pogwiritsa ntchito zida zogwirizanitsa bwino (mankhwala a organometallic opangidwa ndi alkylaluminium ndi titaniyamu tetrachloride). Chifukwa chachikulu chothandizira ntchito, ndi polymerization anachita akhoza anamaliza mwamsanga pa otsika mavuto (0-10 atm) ndi otsika kutentha (60-75 ° C), choncho dzina otsika-anzanu ndondomeko. Polyethylene yomwe imachokera imakhala ndi mawonekedwe osasunthika, ozungulira, omwe amachititsa kuti kachulukidwe kwambiri (0.941-0.965 g/cm³). Poyerekeza ndi LDPE, HDPE imawonetsa kukana kutentha kwambiri, makina amakina, komanso kukana kupsinjika kwa chilengedwe.
Makhalidwe a Polyethylene
Polyethylene ndi pulasitiki yoyera ngati yamkaka, ngati sera, yowoneka bwino, yomwe imapangitsa kuti ikhale yotchingira bwino komanso yopangira mawaya ndi zingwe. Ubwino wake waukulu ndi:
(1) Zabwino kwambiri zamagetsi: kukana kwakukulu kwa kutchinjiriza ndi mphamvu ya dielectric; chilolezo chochepa (ε) ndi dielectric loss tangent (tanδ) kudutsa ma frequency osiyanasiyana, kudalira pafupipafupi, kupangitsa kuti ikhale pafupifupi dielectric yoyenera pazingwe zoyankhulirana.
(2) Zabwino zamakina: zosinthika koma zolimba, zotsutsana ndi mapindikidwe abwino.
(3) Kukana mwamphamvu kukalamba kwamafuta, kufooka kwapang'onopang'ono, komanso kukhazikika kwamankhwala.
(4) Kukaniza madzi abwino kwambiri ndi kuyamwa kochepa kwa chinyezi; kutchinjiriza kukana nthawi zambiri sikuchepa akamizidwa m'madzi.
(5) Monga zinthu zomwe sizikhala ndi polar, zimawonetsa kutha kwa gasi wambiri, pomwe LDPE imakhala ndi mpweya wapamwamba kwambiri pakati pa mapulasitiki.
(6) Mphamvu yokoka yotsika, yonse pansi pa 1. LDPE ndi yodziwika kwambiri pafupifupi 0.92 g/cm³, pamene HDPE, ngakhale kuti imakhala yochuluka kwambiri, ili pafupi ndi 0.94 g/cm³.
(7) Zinthu zabwino zopangira: zosavuta kusungunula ndikuyika pulasitiki popanda kuwola, zimaziziritsa mosavuta, ndikupangitsa kuwongolera bwino kwa geometry ndi miyeso yazinthu.
(8) Zingwe zopangidwa ndi polyethylene ndizopepuka, zosavuta kuziyika, komanso zosavuta kuzimitsa. Komabe, polyethylene imakhalanso ndi zovuta zingapo: kutentha kochepa kofewa; kuyaka, kutulutsa fungo la parafini likawotchedwa; kukana kupsinjika kwa chilengedwe komanso kukana kukwapula. Chisamaliro chapadera chimafunika mukamagwiritsa ntchito polyethylene monga kutchinjiriza kapena kutsekereza zingwe zapansi pamadzi kapena zingwe zomwe zimayikidwa m'madontho opindika.
Pulasitiki ya Polyethylene ya Mawaya ndi Zingwe
(1) General-Purpose Insulation Polyethylene Pulasitiki
Amapangidwa ndi polyethylene resin ndi antioxidants.
(2) Pulasitiki ya Polyethylene Yosagwirizana ndi Nyengo
Makamaka amapangidwa ndi polyethylene resin, antioxidants, ndi carbon wakuda. Kukana kwanyengo kumadalira kukula kwa tinthu, zomwe zili, komanso kubalalitsidwa kwa mpweya wakuda.
(3) Kupsinjika Kwachilengedwe-Crack Resistant Polyethylene Pulasitiki
Amagwiritsa ntchito polyethylene yokhala ndi cholozera chosungunuka chotsika pansi pa 0.3 komanso kugawa kwapang'onopang'ono kwa maselo. Polyethylene imatha kulumikizidwanso kudzera mu radiation kapena mankhwala.
(4) Pulasitiki ya Polyethylene Yowonjezera Mphamvu Yamagetsi
Kutchinjiriza kwa chingwe champhamvu kwambiri kumafuna pulasitiki yoyera ya polyethylene, yowonjezeredwa ndi zowongolera ma voltage ndi ma extruder apadera kuti apewe kupanga zopanda kanthu, kupondereza kutulutsa utomoni, ndikuwongolera kukana kwa arc, kukana kukokoloka kwa magetsi, komanso kukana kwa corona.
(5) Semiconductive Polyethylene Pulasitiki
Amapangidwa powonjezera kaboni wakuda ku polyethylene, nthawi zambiri amagwiritsa ntchito tinthu tating'onoting'ono tomwe timapanga mpweya wakuda.
(6) Thermoplastic Low-Smoke Zero-Halogen (LSZH) Polyolefin Cable Compound
Pagululi limagwiritsa ntchito utomoni wa polyethylene monga maziko ake, kuphatikiza zoletsa moto za halogen zopanda mphamvu, zoletsa utsi, zotsitsimutsa matenthedwe, antifungal agents, ndi zopaka utoto, zokonzedwa kudzera mu kusakaniza, pulasitiki, ndi ma pelletization.
Crosslinked Polyethylene (XLPE)
Pansi pa ma radiation amphamvu kwambiri kapena ma crosslinking agents, mawonekedwe amtundu wama cell a polyethylene amasintha kukhala mawonekedwe amitundu itatu (network), kutembenuza zinthu za thermoplastic kukhala thermoset. Ikagwiritsidwa ntchito ngati insulation,Zithunzi za XLPEimatha kupirira kutentha kosalekeza mpaka 90 ° C ndi kutentha kwafupipafupi kwa 170-250 ° C. Njira zophatikizira zimaphatikizira kuphatikizika kwakuthupi ndi mankhwala. Kuwoloka kwa irradiation ndi njira yakuthupi, pomwe mankhwala omwe amagwiritsidwa ntchito kwambiri ndi DCP (dicuyl peroxide).
Nthawi yotumiza: Apr-10-2025