M'munda wamagetsi, chimodzi mwazinthu zofunika kwambiri pa mawaya amagetsi ndi zingwe ndi zotchingira ndi ma jacketing zida.Kwa zaka zambiri, zida zopangira zida zamagetsi zomwe zidadziwika kale zinali mapepala okhala ndi mafuta chifukwa champhamvu zake zamagetsi.Ilinso ndi mphamvu yopirira kuchulukitsitsa kwa kutentha kwambiri popanda kuwonongeka kwambiri.Komabe, chifukwa cha hygroscopicnature yake, chitsulo m'chimake ndi chinyezi dzimbiri.Chifukwa chake, padali kufunikira kwanthawi yayitali kwa zida zotchingira zamagetsi, zomwe zinali ndi kuphatikiza kwachilengedwe kopanda hygroscopic kwa thermoplasticmaterials.
Kukonzekera kwa ma polima ophatikizika kumatha kuchitika ndi njira ziwiri zosiyana.Imodzi ndi chemicalmethod ndipo ina ndi njira ionizing.Ngakhale kuzindikirika kwa kuphatikizika kumeneku kwadutsa zaka 150, kuphatikizika kwa ma radiation ya ionizing kudawonetsedwa koyamba ndi Charlesby.Njira yolumikizira ma radiation ndiyomwe imapanga mawaya ang'onoang'ono komanso a thinwall motero mawaya omwe amagwiritsidwa ntchito pazida zamagetsi ndi zamagetsi amapangidwa ndi njira yolumikizira ma radiation.Njirayi ndi yopindulitsa chifukwa chosagwiritsa ntchito mphamvu zochepa ndipo imafunikira malo ochepa.Njira ya radiation imayendetsedwa mosavuta ndipo imatha kupulumutsa mphamvu komanso kuwononga chilengedwe.Zomwe zimapangidwira pakuwoloka kwa radiation ndizofupikitsidwa motere: (1) Liwiro la mzere wopangira litha kuwongoleredwa.High liwiro chophimba (extrusion) n'zotheka, monga palibe chofunika crosslinking wothandizira.Pogwiritsa ntchito accelerator yokhala ndi mphamvu zambiri komanso mphamvu zochepa, kuthamanga kwachangu kungathe kupezedwa.(2) Kufanana kwa crosslinking ndikwabwino kwambiri.Kuphatikizika yunifolomu posankha makina oyenerera ndikutengera kapangidwe kabwino ka kudyetsa waya kumatha kuchitika.(3) Mitundu yosiyanasiyana ya ma polima imatha kukonzedwa, kutengera kuchuluka kwa kulumikizana ndi ma radiation crosslinkingprocess.Kuphatikiza apo, njira yochiritsira ma radiation ndiyofunika kwambiri kuposa njira yochizira nthunzi.M'kati mwa machiritso a thesteam, madzi olowera mu polima pansi pa mphamvu ya nthunzi yochuluka amapanga 'microvoids' angapo, omwe angapangitse kuwonongeka kofanana ndi mtengo pamene chingwe chikugwira ntchito.Ngakhale kuti chodabwitsachi ndi chovuta kwambiri, mitengo imatha kukula ndikupangitsa kuchepa kwa mphamvu ya dielectric ya zingwe.Kupatula izi, njira yochiritsira nthunzi imakhala ndi zovuta zina pakugwiritsa ntchito mphamvu: (a) kuthamanga kwa nthunzi kumafunika kuti munthu akhale ndi kutentha kwakukulu;(b) mphamvu ya kutentha kwa kunja kwa chingwe ndi yochepa ndipo (c) kuchuluka kwa mphamvu kumagwiritsidwa ntchito ndi woyendetsa chingwe, zomwe zimapangitsa kuti kutentha kuchepetse komanso nthawi yayitali yolumikizirana.Kuchiritsa kwa ma radiation ndi njira yodziwikiratu.Komabe, zili ndi vuto kuti kuchuluka kwa ma elekitironi kunayima ndi/kapena kupangika pansanjika yotchinga ndi mpweya kumapangitsanso kusweka kwapang'ono ngati mtengo pakuyatsa ndi pambuyo pake.Ndizosiyana kotheratu ndi 'njira yopanda madzi'.Popeza chingwe cha polima chimakhala ndi chinyezi chachikulu komanso ma voids akulu, njira yochiritsa ndiyofunikira.Kupatula pazabwino zomwe tafotokozazi, zida za semiconductor zitha kuyambitsidwa mosavuta munjira yochiritsira ma radiation zomwe sizili zophweka ngati njira yakuchiritsa nthunzi chifukwa zida zambiri sizingathe kupirira kutentha kwambiri komanso kupanikizika.
Njira yophatikizira ma radiation imathandizanso kuti matrix apangidwe.Iyi ndi njira yapadera yophatikizira matrix pa insulating imodzi.Njirayi imaphatikizapo kuyimitsa polima wamsana wokhala ndi monoma yoyenera polumikiza ndikuyika motsatira polima pamwamba pa msana.Kupatula machitidwe otsekereza, pakadali pano polima imatha kukhala ngati yoyendetsa.Ngakhale sichinakhazikikebe, chikhoza kuwonetsa ntchito zingapo zomwe zingatheke monga EMI kutchinga, kupangira zokutira ndi antistatic agents.Bhattacharya etal.akonza zophatikizika polima–FEP-g-(AA)–PPY ndi polima–FEP-g-(sty)–PPY.Poyamba, polymer-FEP idawulutsidwa mawonekedwe a Co-60 ndipo filimuyo idamizidwa mumitundu yosiyanasiyana ya ma monomers.PPy kenako idayikidwa pamwamba pake yomezanitsidwa ndi oxidative polymerizationof pyrrole pogwiritsa ntchito ferric chloride monga oxidant.Kukaniza pamwamba kumachepa ndipo ndi dongosolo la104-105ohm/cm2.Kukaniza pamwamba kumadalira kuchuluka kwa kulumikiza kwa monomers.Pogwiritsa ntchito njirayi, ma conductivity a pamwamba m'malo mochulukitsa amatha kuwonjezeka.Photoconductingbehaviour ya filimuyi imathanso kuperekedwa ndi njira yolumikizira.Cellulose acetate-g-(N-vinyl carbazole) ndi cellulose acetate-g-(N-vinyl carbazole-methyl methacylate) ndi zitsanzo za filimu yopangira zithunzi.
M'makampani amagetsi amagetsi, makamaka polyethylene, polyvinyl chloride (PVC), mphira wa EPDM amagwiritsidwa ntchito.Polyethylene imagwiritsidwa ntchito chifukwa champhamvu zake zamagetsi komanso nthawi yayitali.Polyethylene yocheperako pang'ono imakondedwa kuposa ya high-densitypolyethylene chifukwa cha zifukwa zingapo. Zifukwa zake ndi izi: (a) kusinthasintha kwambiri;(b) mphamvu yapamwamba ya dielectric kuposa polyethylene yochuluka kwambiri;(c) moyo wautali kuposa HDPE;(d) zovuta kwambiri kuzikonza kuposa HDPE ndi (e) chiopsezo chochepa cha kuphatikizidwa kwa voids mu insulation ya LDPE, yomwe imayambitsa ionisation.Ngakhale zabwino zonsezi, LDPE ili ndi zofooka zake ngati cholumikizira chingwe.Pokhala polima wa thermoplastic, kutentha kwake kumakhala kofewa mozungulira 105–115⬚C ndipo chizolowezi chosweka mtima chimachitika ikakumana ndi zinthu zina zogwira ntchito pamwamba.Kuphatikizika kwa mamolekyu a polyethylene kumapangitsa kuti matenthedwe komanso zinthu zakuthupi zikhale bwino pomwe mphamvu zake zamagetsi sizisintha.Crosslinked polyethylene ndiye, kotero, salinso thermoplastic polima.Imafewetsa pamalo osungunuka a crystalline a polyethylene ndipo imatengera kusinthasintha, ngati mphira, chinthu chomwe imasunga pakatentha kwambiri, mpaka imakhazikika popanda kusungunuka pa 300⬚C.Chizoloŵezi cha kupsinjika maganizo chizimiririka ndipo kukana kukalamba mu mpweya wotentha kumapezedwa.Zingwe za polyethylene zophatikizika zimakondedwa kwambiri chifukwa champhamvu zake zamagetsi ndi thupi.Imatha kunyamula mafunde akulu, kupirira kupindika kwa ma radius yaying'ono komanso kulemera kwake, kulola kuyika kosavuta komanso kodalirika, mwachitsanzo, ilibe malire chifukwa ilibe mafuta aliwonse ndipo motero ilibe zolephera chifukwa chakusamuka kwamafuta mumafuta. chingwe chingwe.Komanso si kawirikawiri amafuna zitsulo m'chimake.Chotero, ndi wopanda zolephera wachilendo zitsulo sheathed zingwe, dzimbiri ndi kutopa.Masiku ano, ma radiation crosslinking amagwiritsidwa ntchito polima osati polyethylene komanso ma polima ena monga polyvinyl chloride, polyisobutylene etc. Payokha PVC ndi polima wosakhazikika kwambiri.Zinayamba kupeza phindu pazamalonda pokhapokha atapanga njira zothandiza zokhazikitsira bata.Mothandizidwa ndi ma modifying agents (stabilisers, plasticisers, fillers ndi zina zowonjezera), PVC ikhoza kupangidwa kuti iwonetse zinthu zambiri, kuyambira zolimba kwambiri mpaka zosinthika kwambiri.Kusiyanasiyana kwakugwiritsa ntchito kwake komanso mtengo wake wotsika ndizomwe zimayambitsa kufunikira kwake pamsika wapadziko lonse lapansi.
Kuti muwonjezere mphamvu yolumikizirana, ma polima sagwiritsidwa ntchito kawirikawiri mu mawonekedwe awo oyera.Mapulasitiki, ma antioxidants, zodzaza zili ndi gawo lawo mwanjira yawo yogawira zinthu zofunika.The Addis bwino pa crosslinking ndondomeko.Mapulasitiki amawonjezeredwa ku ma polima kuti achepetse kuwonongeka kwa zinthu za polima.Iwo amakhudza crosslinking nthawi iliyonse iwo kutenga nawo mbali m'badwo wa freeradicals kapena kulowa kufalitsa zimachitikira.Dibutyl phthalate, tritolyl phosphate ndi diallyl phosphate ndi zitsanzo zodziwika bwino za plasticiser ku PVC.Kusinthasintha ndi elasticity, zomwe ndizofunikira kwambiri pakutchinjiriza kwamagetsi, zimasinthidwa ndikuwonjezera mapulasitiki ku PVC.Kwenikweni, ngati PVC, yomwe ili polar chifukwa cha kusakhazikika bwino, imapangitsa kuti pakhale zomangira zolimba za intermolecular, zomwe zimalumikizana mwamphamvu ndi unyolo wa macromolecular, palimodzi zimapangitsa kuti zisasunthike.Ma Antioxidants ndi gulu lina la zowonjezera, zomwe ndizofunikira pazosakaniza zilizonse zomwe zimapangidwira kuti zitheke kufananitsa kukhazikika kwapamwamba kwa thermooxidative pakupanga polima.Nthawi zambiri zimakhudza ma crosslinking byscavenging radicals, omwe amatha kupanga crosslinks.RC (4,4-thio-bis(6-tert-butyl-3-methyl phenol), MB(Mercapto benzoimidazole) ndi zitsanzo za antioxidants zomwe zimagwiritsidwa ntchito ndi Ueno et al. Kuphatikiza pa mapulasitiki ndi ma antioxidants, mitundu imafunikira, Mitundu ya mapulasitiki imaphatikizapo mitundu yosiyanasiyana ya inorganic and organicmaterials. Zapezeka kuti zokolola za ma radicals mu polyethylene zidawonjezeka ndi 50%, pamene aerosil pang'ono (0.05%) awonjezeredwa. polyethylene, kumene macromolecules akhoza kukhala mu chikhalidwe chosafanana cha zovuta zopanda malipiro.Kuphatikiza apo, kuphatikizika kwa kuwala kophatikizana kosakanikirana kumatha kukhudza kufalikira kwa maulalo am'mphepete mwa unyolo wa polima.
Mwachidule, ma radiation amatenga gawo lofunikira pakukonza ma polima omwe amagwiritsidwa ntchito pamagetsi.'Radiation crosslinking' ndi zochitika zomwe ma polima amatha kuwongolera.Ndi njira yapamwamba kwambiri monga 'vulcanisation' ili ndi malire.Kuchita bwino kwa crosslinking kumatha kupitsidwanso ndi kusankha ma monomers abwino.Munjira yophatikizira ma radiation, mapulasitiki, zodzaza ndi zotchingira moto ndizothandiza kwambiri pakuwoloka kwa ma radiation.Njira ya radiationcrosslinking ndiyothandizanso kwambiri pokonzekera zida za semiconductor.Kupatula izi, njira yolumikizira ma radiation ingagwiritsidwenso ntchito pokonzekera filimu yophatikizika ndi mafilimu okhala ndi machitidwe a photoconducting.
Nthawi yotumiza: May-02-2017