Uluntu lusebenzise izixhobo zendalo zepolymeric ezinje ngamaplanga, ufele kunye noboya ukusukela ekuqaleni kwembali, kodwa iipolymers zokwenziwa zabakho kuphela emva kophuhliso lwetekhnoloji yerabha kwiminyaka yoo-1800.Isixhobo sokuqala sokwenziwa kwepolymer, icelluloid, yaqanjwa nguJohn Wesley Hyatt ngo-1869, ukusuka kwi-cellulose nitrate kunye necamphor.Impumelelo enkulu kwiipholima zokwenziwa kukuveliswa kwe-Bakelite ngu-Leo Hendrik Baekeland ngo-1907. Umsebenzi ka-Hermann Staudinger ngeminyaka yoo-1920 wawubonisa ngokucacileyo ubume be-macromolecular yamatyathanga amade aphinda-phinda iiyunithi.1 Igama elithi 'polymer' lisuka kwisiGrike, kwaye lithetha 'ezininzi. iinxalenye'.Ukukhula ngokukhawuleza kweshishini lepolymer kwaqala kungekudala ngaphambi kweMfazwe yeSibini yeHlabathi, ngophuhliso lweepolima ze-acrylic, i-polystyrene, inayiloni, i-polyurethanes kunye nokuqaliswa okulandelayo kwe-polyethylene, i-polyethylene terephthalate, i-polypropylene kunye nezinye iipholima kwi-1940 kunye ne-1950s.Ngelixa kuphela iitoni ezimalunga nesigidi esi-1 zaveliswa ngo-1945, ukuveliswa kweeplastiki ngomthamo kwadlula ezo zentsimbi ngo-1981, kwaye umsantsa ukhula ngokuqhubekayo ukususela ngoko.
Iipholima ezisulungekileyo azifane zisetyenzwe ngokwazo.Zidityaniswa nezinye izinto, ngokuqhelekileyo ngokuxubana ngoomatshini okanye ukunyibilika kombuso ukuxuba ukuvelisa iipellets, umgubo okanye iikes eziza kusetyenziswa kwimisebenzi yokucutshungulwa okulandelayo.Iikhompawundi zinokubandakanya i-Ž llers (ukunciphisa iindleko), iziqinisekiso, ezinye iipholima, ii-colorants, i-ame retardants, izizinzi (ukuthintela ukuwohloka kokukhanya, ubushushu okanye ezinye izinto zokusingqongileyo) kunye nezixhobo ezahlukeneyo zokulungisa.
Iipholima zokwenziwa zingahlelwa ngokweendidi ezimbini.I-Thermoplastics (eyona volumu inkulu) inokunyibilikiswa ngokufudumeza, i-solidiŽ ed ngokupholisa kunye nokunyibilika ngokuphindaphindiweyo.Iindidi eziphambili ziyi-polyethylene (PE), i-polypropylene (PP), i-polystyrene (PS), i-polyvinyl chloride (PVC), i-polycarbonate (i-PC), i-polymethyl methacrylate (PMMA), i-polyethylene terephthalate (PET) kunye ne-polyamide (PA, nylon).I-Thermosets yenziwa lukhuni kukufakwa kobushushu kunye noxinzelelo, ngenxa yokudibanisa, oko kukuthi ukudalwa kothungelwano olusisigxina lwe-threedimensional networks.Azinakuthanjiswa ngokufudumeza ukuze ziphinde zilungiswe.I-Bakelite, i-epoxies kunye ne-polyurethanes ezininzi zi-thermosets.
Ujongo lwangoku lunikezelwe kuphela ekusetyenzweni kwe-thermoplastics.Ii-thermoplastics zorhwebo zihlelwa ngokokusebenza kwazo 'njengemveliso' (ukusebenza okuphantsi, okufana ne-PE, PP, PS kunye ne-PVC), 'iNjineli' (efana nePC, inayiloni kunye ne-PET) okanye 'inkqubela phambili' (ukusebenza okuphezulu, okufana iipolymers zekristale engamanzi (LCPs), i-polyphenylene sulphide (PPS) kunye ne-polyetheretherketone (PEEK)).Ukukhula okugqabhukileyo obekulindelwe kubunjineli kunye neepolima eziphucukileyo azizange zenzeke.Ukusetyenziswa kweeplastiki bekulokhu kukhula ngokuqhubekayo kule minyaka ingamashumi amathathu idlulileyo, kodwa ikakhulu kudidi lwemveliso.Okwangoku, iipolima zemveliso zifikelela kwi ~ 88% yomthamo oveliswayo, iiplastiki zobunjineli ezi-3 ~ 12% kwaye ziqhubele phambili ngaphantsi kwe-1%.Nangona amaxabiso eepolima eziphucukileyo ngekhilogram nganye ephezulu kakhulu kunalawo eepolima zemveliso, ixabiso lawo lehlabathi kuqoqosho lisencinci kakhulu.
Iiplastiki zemveliso zinamandla aphantsi kunye nokuqina xa zithelekiswa nesinyithi okanye iiseramikhi, kwaye zikholisa ukubonisa ukukhahlela phantsi kwamandla asetyenzisiweyo.Zikwanazo nemida yobushushu ekusebenziseni kwazo njengeziqina (ezininzi ziyanyibilika kuluhlu lwe-100–250°C).Imodyuli eqinile yeeplastiki zemveliso yi ~1 GPa (xa kuthelekiswa ne-210 GPa yentsimbi).Uphuculo lwe-Signi-Ž cant lungaphunyezwa ngolungelelwaniso lwamakhonkco epholima.Ngokwenyani, iibhondi zekhabhoni- carbon zomelele kakhulu, kwaye ii-polyethylenes ezi-single Ž ziyakhala ziye ziveliswa ngexabiso lemodulus elidlula elo lentsimbi.Ukuqhelaniswa okuphezulu kunokufezekiswa ngobuchule obukhethekileyo bokucubungula, umzekelo i-extrusion kunye nomzobo olandelayo kumaqondo okushisa aphantsi.Kwiqondo lobushushu eliphantsi amatyathanga epolymer anokuhamba okulinganiselweyo, kwaye ukuqhelaniswa kuhlala emva kokusolula.Ukufunyaniswa kwamva nje kunye nophuhliso lwesiza esinye, i-metallocene esekwe kwi-catalysts ibangele amabakala amatsha eepolima zemveliso ezilawule ulwakhiwo lwemolekyuli eneempawu eziphuculweyo.
Imveliso yehlabathi yeepolymers inyuke3 ukusuka kwi-27 yezigidi zeetoni ngo-1975 ukuya kwi- ~ 200 yezigidi zeetoni ngonyaka ngo-2000 kwaye isakhula.Ngokwengxelo yamva nje, ukuthunyelwa kwe-4 yeemveliso zeplastiki e-USA ngo-2000 kwafikelela kwi-330 yeebhiliyoni zeerandi, kwaye amashishini abonelela ngeenkonzo athengisa i-90 yeebhiliyoni zeerandi, nto leyo ezisa inani elipheleleyo leebhiliyoni ezingama-420 zeedola.Iyonke ingqesho yayiqikelelwa kwi-2 .4 yezigidi - malunga ne-2% yabasebenzi base-US.Ukukhula kweshishini lepolymer kusisiphumo sokudityaniswa okukhethekileyo kweepropathi zeemveliso zeplastiki, ezibandakanya ukubunjwa lula kunye nokwenziwa, ukuxinana okuphantsi, ukuxhathisa ukubola, ukugqunywa kombane kunye ne-thermal, kunye nokuqina okuthandekayo kunye nokuqina kwiyunithi nganye yobunzima.
Ixesha lokuposa: Feb-04-2018