Polymerization zimachitika

Mapuloteni ndiwo makina omwe ali ndi maselo akuluakulu omwe amafika maulendo angapo. Polymerization zimachitika pakupanga zipangizo zamakono zofuna zosiyanasiyana. Iwo ali ndi mphamvu zazikulu pang'onopang'ono, amachepetsedwa ndi Kutentha ndipo amatha kuumba mosavuta, zomwe zimalola kupeza zinthu zamakono ndi zazikulu zosiyanasiyana. Mapuloteni amalowa m'malo owonongeka, amakhala ndi zida zogwiritsira ntchito magetsi ndipo sagwidwa ndi kutupa. Chifukwa cha zinthu zake zamtundu wapadera, zomwe zimangowonongeka mosavuta pa kaphatikizidwe, gawo la kugwiritsa ntchito zipangizo zamakono zamakono zimapitiriza kukula.

Mukatenthedwa komanso utakhazikika, mankhwalawa amapangidwa m'njira ziwiri.

Kutentha kotentha ndikumachepetsa, ndipo kamodzi kamakhala kozizira, zimakhazikitsanso. Zida zoterezi zimaphatikizapo mankhwala ogwiritsidwa ntchito, mwachitsanzo, polymerization zimachitika alkenes, mwachitsanzo, polyethylene ndi polypropylene. Amatchedwa thermoplastic zipangizo. Polyvinyl kloride ndi polystyrene ali ndi katundu wofanana.

Mitundu ya mtundu umodzi imatha kutenthedwa kamodzi kokha, chifukwa pambuyo pozizira amaumitsa ndipo samachepetsanso kwambiri akamapsa mtima. Zida zimenezi zimatchedwa thermosetting, monga phenol-formaldehyde kapena urea-formaldehyde resins. Thermoplastics ndi thermosets ali ndi ubwino wawo. Yoyamba imatulutsidwa mu mawonekedwe a granular. Mwa iwo, atatha kutenthetsa ndi kutenthetsa, zimagwiritsidwa ntchito ndi mawonekedwe alionse, koma sangathe kuvutikira pakapita ntchito. Zomalizazi zimapezeka mwa mawonekedwe a misala yamadzi.

Ethylene polymerization reaction ingalembedwe mu mawonekedwe otsatirawa: CH2 = CH2 → (-CH2-CH2-) n. Pazifukwa zina, pamaso pa oyambitsa (iwo ndi gaseous oksijeni kapena yankho la organic peroxide mafuta), kusiyana kwa π (kuphatikizapo mgwirizano wawiri) kumachitika pakati pa maatomu a kaboni ndi kuchuluka kwa n-th kwa zida zowonongeka zopangidwa pamodzi. Polymerization zimachitika mwachitsulo chachikulu. Mlingo wolemera wa polima wambiri umadalira mwachindunji nambala n, ndi kukula kwake kumakula. Kulamulira zikhalidwe za polymerization zimachitika, polyethylene kaphatikizidwe kameneka kamapangitsa kukonza zinthu ndi zinthu zomwe zatsimikiziridwa: fluidity (kapena kusungunuka kutuluka mndandanda), mphamvu, unyinji, kutayika kwa dielectric tangent, dielectric nthawi zonse, ndi zina.

Phatikizidwe ya mkulu-polytenhylene kapena polymerization zimachitika mu autoclave kapena tubular reactors pa kutentha mpaka 300 ° C ndi kupanikizidwa kwa 1000 mpaka 3000 atm. Pa nthawi yomweyo, kutentha kwakukulu kumatulutsidwa. Icho chimachotsedwa ndi madzi otentha, omwe amadyetsedwa mu makina a riyakitala. Kuchokera pamyambidwe a madzi omwe amaperekedwa pofuna kuchotsa kutentha, madzi makamaka zimadalira mtundu wa polymer ndi chitetezo cha ndondomekoyi. Ngati madzi sakuyeretsedwa bwino ndipo ali ndi zosafunika zambiri (mwachitsanzo, kuuma kwa salitsi monga calcium ndi magnesium cations, silicic acid anions , klorini ndi ena), kenaka amaika mu jekete ya riyakitala kapena ayamba kusula chitsulo. Chifukwa cha kusintha kwa makulidwe a makinawa, kutentha kutentha padziko lonse kumakhala kosafanana, ndipo nyengo ya kutentha ya polymerization ikhoza kusasinthika. Ndi kuwonjezeka kwadzidzidzi kwa kutentha, poizoni wa polymer kapena kuwonongeka kwake kungakhoze kuchitika ndi chiwonongeko cha riyakitala.

The polymerization anachita zomwe zimachititsa mapangidwe polyethylene angathenso kuchitika pamunsi mavuto ndi kutentha. Koma izi zimafuna kuthandizira. Ngati mpweya wa polyethylene wotuluka kuchokera mu chokwera utayika ngati mawonekedwe a ethylene osagwiritsidwa ntchito, omwe amagawanika ndipo polima ndi granulated, polyethylene yomwe imatulutsidwa pang'onopang'ono imachoka mu mphikawo ngati ufa, makamaka, kuyimitsidwa mu hydrocarbon solvent. Mpweyawo umagawidwa ndi zosungunuka ndikusambitsidwa ndi zosafunika za chothandizira, ndiyeno granulated pa zipangizo zapadera zotchedwa extruder.

Choncho, ethylene polymerization anachita mu mafakitale amagwiritsidwa ntchito pa kaphatikizidwe ka polyethylene. Malinga ndi GOST 16338-85 otsika kwambiri polyethylene wa kuyimitsidwa ndi mpweya magawo sukulu amapangidwa, malinga ndi GOST 16337-77 mkulu-pressure polyethylene amapangidwa onse autoclave ndi tubular sukulu.