Lero, ndikukupatsani mwachidule chiyambi cha mbiri ya mapulasitiki.

Pulasitiki yoyamba yopangidwa kwathunthu m'mbiri ya anthu inali utomoni wa phenolic wopangidwa ndi American Baekeland wokhala ndi phenol ndi formaldehyde mu 1909, womwe umadziwikanso kuti Baekeland plastic. Utomoni wa phenolic umapangidwa ndi condensation reaction ya phenols ndi aldehydes, ndipo ndi wa thermosetting plastics. Njira yokonzekera imagawidwa m'magawo awiri: gawo loyamba: choyamba kupanga polymer kukhala compound yokhala ndi linear degree yotsika ya polymerization; gawo lachiwiri: gwiritsani ntchito high temperature therapy kuti musinthe kukhala polymer compound yokhala ndi high polymerization.
Pambuyo pa zaka zoposa zana za chitukuko, zinthu zopangidwa ndi pulasitiki tsopano zili paliponse ndipo zikupitiriza kukula mofulumira kwambiri. Utomoni woyera ukhoza kukhala wopanda mtundu komanso wowonekera bwino kapena woyera, kotero kuti chinthucho sichikhala ndi mawonekedwe oonekera bwino komanso okongola. Chifukwa chake, kupatsa zinthu zopangidwa ndi pulasitiki mitundu yowala kwakhala udindo wosapeŵeka wa makampani opanga mapulasitiki. Nchifukwa chiyani mapulasitiki apangidwa mofulumira kwambiri m'zaka 100 zokha? Makamaka chifukwa ali ndi ubwino wotsatira:

1. Mapulasitiki amatha kupangidwa pamlingo waukulu. (Kudzerankhungu ya pulasitiki)

2. Kuchuluka kwa pulasitiki ndi kopepuka ndipo mphamvu yake ndi yayikulu.

3. Pulasitiki imatha kukana dzimbiri.

4. Pulasitiki ili ndi mphamvu zabwino zotetezera kutentha komanso zoteteza kutentha.

Pali mitundu yambiri ya mapulasitiki. Kodi mitundu ikuluikulu ya mapulasitiki otchedwa thermoplastics ndi iti?

1. Polyvinyl chloride (PVC) ndi imodzi mwa mapulasitiki akuluakulu omwe amagwiritsidwa ntchito kwambiri. Pakati pa mapulasitiki asanu apamwamba padziko lonse lapansi, mphamvu yake yopangira ndi yachiwiri kuposa polyethylene. PVC ili ndi kuuma bwino komanso kukana dzimbiri, koma ilibe kusinthasintha, ndipo monomer yake ndi yoopsa.

2. Polyolefin (PO), yomwe imapezeka kwambiri ndi polyethylene (PE) ndi polypropylene (PP). Pakati pawo, PE ndi imodzi mwa zinthu zazikulu kwambiri zopangidwa ndi pulasitiki. PP ili ndi kachulukidwe kochepa, si poizoni, siinunkhira bwino ndipo imapirira kutentha bwino. Itha kugwiritsidwa ntchito kwa nthawi yayitali kutentha kwa madigiri pafupifupi 110 Celsius.supuni ya pulasitikiimapangidwa ndi chakudya cha PP.

3. Ma resini a styrene, kuphatikizapo polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (ABS) ndi polymethyl methacrylate (PMMA).

4. Polyamide, polycarbonate, polyethylene terephthalate, polyoxymethylene (POM). Mtundu uwu wa pulasitiki ungagwiritsidwe ntchito ngati zinthu zomangira, zomwe zimadziwikanso kuti zinthu zaukadaulo.

Kupezeka ndi kugwiritsidwa ntchito kwa mapulasitiki kwalembedwa m'mabuku akale, ndipo chinali chinthu chachiwiri chofunikira chomwe chinakhudza anthu m'zaka za m'ma 1900. Pulasitiki ndi chozizwitsa padziko lapansi! Masiku ano, tinganene mosakokomeza kuti: "Miyoyo yathu singalekanitsidwe ndi pulasitiki"!