The polymerization kuita

Polymers - yeimwe vane yakakwirira samolecular uremu kusvika zviuru zvakawanda dzakabatana. The polymerization kuita hwaro ano zvinhu kugamuchira siyana nerevane uye zvivako. Vane yakaderera arambe achirema vari zvikuru yakasimba, anokwanisa kunyevenutsa apo nenharo uye nyore kukundwa kuumbwa, izvo zvinoita kuti vawane zvibereko siyana mazano uye hukuru. The Polymers vari inert kune kungatikanganisa runyararo, nhaka zvemagetsi insulating zvivako uye asingauyi zvinoparadza. Nokuda yakasiyana ehupfumi ayo, izvo zvinogona nyore kugadziridzwa panguva pavaipfuura kwetunhu, kushandiswa ano polymeric zvinhu zviri kuramba richikura.

Kana muchidziisa uye kutonhora zvibereko kwemakemikari kugadzirwa ingozvibatai nenzira mbiri.

Vamwe kupfavisa kana nenharo uye kuomesa kana haachandidi zvakare. zvinhu zvakadaro zvinosanganisira mishonga inobva gadziriro riri Somuenzaniso, ari polymerization maitiro alkenes, i.e., polyethylene uye polypropylene. Dzinonzi thermoplastic zvinhu. Rine ehupfumi zvakafanana sezvo polyvinyl chloride uye polystyrene.

Polymers imwe mhando anogona neshungu kamwe chete, sezvo vanoomesa pashure kutonhora uye zvakawanda regai kunyevenutsa pasi kudziyisa. zvinhu izvi dzinonzi thermosetting, zvinosanganisira phenol-formaldehyde kana urea-formaldehyde Inogadzirwa nemasiridzi anobuda mumiti. Thermoplastics uye thermosets vane dzavo zvakanaka. First kugadzirwa granular chimiro. Nezvavo, pashure muchidziisa uye kunyoroveswa takagadzirira zvinhu chero chimiro, asi haagoni neshungu panguva oparesheni. Ekupedzisira anobudiswa somunhu gummy guru.

ethylene polymerization zvinogona kunyorwa sezvinotevera: CH2 = CH2 → (-CH2-CH2-) n. Under zvimwe zvinhu, pamberi ane initiator (ivo nyasha okisijeni gasi kana mhinduro ine makemikari peroxide mumafuta) inoitika pakati kabhoni maatomu π-chisungo pakakoromoka (zvimwe miviri chisungo) uye remubatanidzwa pakati N-Nogo nhamba kuumbwa vakasununguka radicals. The polymerization kuita makabva pedyo yakakura cheni mashandiro. The samolecular kurema ari polymer zvinhu iri zvakananga novimba nhamba N, pamwe kwayo kuwedzera inokura. Nokuchinja zvinhu zviri polymerization zvakaitwa, iro kwetunhu polyethylene opareta inowana kuwana zvinhu pamwe kutsvakwa nzvimbo: fluidity (kana achanyunguduka indekisi), simba, arambe achirema, dielectric kurasikirwa tangent, dielectric kugara, uye vamwe.

Kwetunhu mukuru-kumanikidza polyethylene kana polymerization maitiro ari kuitwa autoclave kana tubular reactors pane kutonhora anosvika 300 ° C uye kumanikidzwa 1000 kusvika 3000 ATM. Izvi anosunungura rakawanda chaizvo kupisa. It chinobviswa nemvura inopisa riri nechikoro kuti reactor bhachi. The dhigirii yokuchena kusvitsa kuti vakuchidzire nokubviswa mvura zvinoenderana chatingatevedzera polymeric zvinhu uye muitiro makachengeteka. Kana mvura iri havaratidzi vakachenesa uye rine netsvina zvakawanda (semuenzaniso, noukukutu munyu sezvo calcium magnesium cations, anions silicic acid, kuiisa chlorine, etc.), kuti reactor bhachi vakaumba deposits kana simbi anotanga kukanganisa. Nokuda kuchinja reactor rusvingo Ukobvu kupisa nounzenza mhiri kwayo pamusoro anova gogonera, uye tembiricha kuti polymerization ezvinhu anogona kuva unmanageable. With kunoshamisa Zvakawanikwa oxidation tembiricha iri polymer zvingaitika kana manyowa pamwe kuparadzwa reactor.

The polymerization maitiro, somugumisiro iyo kuumbwa polyethylene, anogona kutora nzvimbo panguva yakaderera tembiricha uye kumanikidzwa. Asi ichi zvinoda anowedzera. Ine unreacted ethylene, iyo zvino vakaparadzaniswa uye polymer akanga pelletized, ari polyethylene ikabereka pasi pasi kumanikidzwa, haazotaurwizve reactor sechipiriso upfu, kana kutoti kuturika ari yeHydrocarbon solvent kana refu kumanikidzwa polyethylene kubva reactor sezvo uchanyangadika migumo. The upfu chakaparadzaniswa kubva solvent uye netsvina kusukwa kubva anowedzera, uye ipapo granulated uye anokosha midziyo inonzi extruder.

Nokudaro, polymerization maitiro ethylene ari indasitiri akashandiswa kwetunhu polyethylene. GOST 16338-85 kubudisa yakaderera-kufurirwa polyethylene slurry uye gasi danho mavanga, maererano GOST 16337-77 asunungurwa somupristi-kumanikidzwa polyethylene autoclave kana tubular inoratidza.