Nhasi, ndichakupai sumo pfupi yenhoroondo yepurasitiki.

Purasitiki yekutanga yakagadzirwa zvizere munhoroondo yevanhu yaive phenolic resin yakagadzirwa neAmerican Baekeland ine phenol ne formaldehyde muna 1909, inozivikanwawo seBaekeland plastic. Phenolic resins inogadzirwa ne condensation reaction ye phenols ne aldehydes, uye ndeye thermosetting plastics. Maitiro ekugadzirira akakamurwa kuita matanho maviri: danho rekutanga: polymerize kuita compound ine low linear degree of polymerization; danho rechipiri: shandisa high temperature therapy kuti uishandure kuita polymer compound ine high degree of polymerization.
Mushure memakore anopfuura zana ekugadzirwa, zvigadzirwa zvepurasitiki zvava kwese kwese uye zviri kuramba zvichikura nekukurumidza kunotyisa. Resin yakachena inogona kunge isina ruvara uye yakajeka kana kuti chena pakuonekwa, zvekuti chigadzirwa chacho hachina zvinhu zvakajeka uye zvinokwezva. Saka, kupa zvigadzirwa zvepurasitiki mavara akajeka kwave basa risingadzivisike reindasitiri yekugadzira mapurasitiki. Sei mapurasitiki akakurumidza kukura mumakore zana chete? Zvikuru nekuti ane mabhenefiti anotevera:

1. Mapurasitiki anogona kugadzirwa pahuwandu hwakakura. (Kuburikidza nechiumbwa chepurasitiki)

2. Kuwanda kwepurasitiki kwakareruka uye simba rayo rakakwira.

3. Purasitiki inodzivirira ngura.

4. Purasitiki ine hunhu hwakanaka hwekudzivirira kupisa uye hunhu hwekudzivirira kupisa.

Kune mhando dzakawanda dzepurasitiki. Ndedzipi mhando huru dzethermoplastics?

1. Polyvinyl chloride (PVC) ndeimwe yemapurasitiki anoshandiswa zvakanyanya. Pakati pemapurasitiki mashanu akanakisa pasi rose, kugona kwayo kugadzira ndiko kunotevera polyethylene. PVC ine kuomarara kwakanaka uye inodzivirira ngura, asi haina kusimba, uye monomer yayo ine chepfu.

2. Polyolefin (PO), inonyanya kushandiswa ipolyethylene (PE) nepolypropylene (PP). Pakati pazvo, PE ndeimwe yezvigadzirwa zvepurasitiki zvikuru zvinoshandiswa. PP ine huwandu hushoma, haina chepfu, haina hwema uye inodzivirira kupisa zvakanaka. Inogona kushandiswa kwenguva yakareba patembiricha inosvika 110 degrees Celsius.chipunu chepurasitikiyakagadzirwa nePP yemhando yechikafu.

3. Maresini eStyrene, anosanganisira polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS) uye polymethyl methacrylate (PMMA).

4. Polyamide, polycarbonate, polyethylene terephthalate, polyoxymethylene (POM). Rudzi urwu rwepurasitiki runogona kushandiswa sechinhu chekuvaka, chinozivikanwawo sezvinhu zveinjiniya.

Kuwanikwa nekushandiswa kwemapurasitiki kwakanyorwa munhoroondo dzekare, uye ndicho chaive chigadzirwa chechipiri chakakosha chakakanganisa vanhu muzana remakore rechi20. Zvechokwadi mapurasitiki chishamiso panyika! Nhasi, tinogona kutaura tisingawedzeredzi kuti: "Hupenyu hwedu hahugoni kuparadzaniswa nepurasitiki"!