Hauv qhov teeb meem no, peb txuas ntxiv peb txoj kev nkag siab ntawm plastics los ntawm kev xav tshuaj.
Cov khoom ntawm plastics: Cov khoom ntawm plastics nyob ntawm seb cov tshuaj muaj pes tsawg leeg ntawm cov subunits, seb cov subunits tau npaj li cas, thiab lawv ua li cas.Tag nrho cov yas yog polymers, tab sis tsis yog tag nrho cov polymers yog yas.Cov yas polymers yog tsim los ntawm cov hlua txuas ntawm cov subunits hu ua monomers.Yog tias tib lub monomers txuas, ib homopolymer tsim.Cov monomers sib txawv yog txuas rau daim ntawv copolymer.Homopolymers thiab copolymer tuaj yeem yog linear lossis branched.Lwm yam khoom ntawm cov yas muaj xws li: Cov yas feem ntau yog khoom.Lawv tuaj yeem yog amorphous solids, crystalline solids lossis semi-crystalline solids (microcrystals).Cov yas feem ntau yog cov khoom siv hluav taws xob tsis zoo ntawm cov cua sov thiab hluav taws xob.Feem ntau yog cov insulators nrog siab dielectric zog.Glassy polymers zoo li nyuaj (piv txwv li, polystyrene).Txawm li cas los xij, flakes ntawm cov polymers tuaj yeem siv ua cov yeeb yaj kiab (xws li polyethylene).Yuav luag tag nrho cov yas qhia elongation thaum muaj kev ntxhov siab thiab tsis rov zoo thaum muaj kev ntxhov siab.Qhov no hu ua "creep".Cov yas zoo li yuav ruaj thiab degrade qeeb heev.
Lwm qhov tseeb txog cov yas: Thawj cov khoom siv hluavtaws yog BAKELITE, tsim los ntawm LEO BAEKELAND xyoo 1907. Nws kuj tau sau lo lus "yas".Lo lus "yas" los ntawm Greek lo lus PLASTIKOS, uas txhais tau hais tias nws tuaj yeem tsim los yog pwm.Kwv yees li ib feem peb ntawm cov yas tsim yog siv los ua ntim.Lwm qhov thib peb yog siv rau sab hauv thiab kav dej.Cov yas ntshiab yog feem ntau insoluble hauv dej thiab tsis muaj tshuaj lom.Txawm li cas los xij, ntau cov additives hauv plastics yog tshuaj lom thiab tuaj yeem nkag mus rau hauv ib puag ncig.Piv txwv ntawm cov tshuaj lom ntxiv muaj xws li phthalates.Non-toxic polymers kuj tuaj yeem degrade rau hauv cov tshuaj thaum tshav kub kub.
Tom qab nyeem qhov no, koj puas nkag siab tob txog cov yas?
Post lub sij hawm: Sep-17-2022