Polyvinyl cawv

Polyvinyl cawv yog ib tug hluavtaws polymer uas yog yooj yim soluble nyob rau hauv cov dej. Nws twb tau nyob rau hauv 1924 los ntawm ob chemists - Gonelem thiab lub teb chaws Yelemees - nrog rau cov kev pab los ntawm lub saponification cov tshuaj tiv thaiv.

lub zog

Polyvinyl cawv - ib tug dawb hmoov, muaj tus muaj peev xwm mus tsim tau ib zaj duab xis. Qhov no polymer no muaj zog heev thiab saj zawg zog, tab sis txij li thaum cov nyob ntawm seb qhov zoo tshaj ntawm noo noo (nws absorbs kua), lub tensile zog dua li qub, thiab ib tug loj ductility tshwm sim thaum ib tug kawm ntawv ntawm av noo. Nws muaj lub hygroscopic zog, nws yog yooj yim yaj (mas dej). Nyob rau hauv cov organic solvents xws li cov rog thiab roj, nws tsis yog muaj peev xwm yaj. Thaum uas siv cov no substance twb tsis muaj tshuaj lom los, thiab yog li ntawd yuav muab suav hais tias phem.

muab cawv

Polyvinyl cawv los yog PVA yog npaj los ntawm polyvinyl acetate los ntawm hydrolysis los yog alcoholysis thiab ua nyob rau hauv daim ntawv ntawm granules los yog hmoov. ib tug ntau yam ntawm kev siv technology tshiab txoj kev, los ntawm tej yam yooj yim mus heev thiab lub sij hawm-siv siv nyob rau hauv qhov kev npaj ntawm PVA.

Polyvinyl cawv - qhov siv ntawm

PVA yog tam sim no siv lug. Nws muaj peev xwm ua si lub luag hauj lwm ntawm thickener nrog kua nplaum siv thiab ua thiab zawv plaub hau, nws yuav ua tau ib latex khoom. Nws yog ntse siv los cov restorers ntawm paintings. Vim nws hygroscopic zog, nws yog dav siv nyob rau hauv cov creation ntawm tu txhais tau tias. Tag nrho cov hom ntawm cov pawm, tampons thiab pawm no ntau npau yog ua siv PVA. Tsis txhob hnov qab lub polyvinyl cawv, thiab cov zaub mov producers. Nws yog siv raws li ib tug emulsifier nyob rau hauv qhuav ntawm mayonnaise, kua ntsw, ketchups thiab lwm yam khoom noj khoom haus cov khoom, thiab nws kuj yog siv raws li ib tug tsw enhancer confectionery.

Niaj hnub nimno cov tshuaj, dhau lawm, tau txais ib co ntawm cov thaj chaw ntawm PVA. Nws yog siv nyob rau hauv qhov siv thiab ua tej yam tshuaj, ua ntej subjecting nws kom huv si ntxuav los ntawm impurities. Ophthalmologists polyvinyl cawv yog siv rau cov kev npaj ntawm qhov muag dauv thiab raws li ib tug roj nplua nyeem kev sib cuag lo ntsiab muag. Txawm oncologists tau pom daim ntawv thov nyob rau hauv cov kev kho mob ntawm PVA cancer. Nyob rau hauv kev, nws yuav tsum tau ua tsis yog phais embolization txoj kev. Thiab nws tsis yog tag nrho cov ntau yam ntawm daim ntawv sau npe ntawm polyvinyl cawv nyob rau hauv cov tshuaj.

Nyob rau hauv lub textile kev lag luam PVA yog siv rau kev tshem tawm ntawm static hluav taws xob, thiab daim ntawv - rau daim ntawv ub. Tsis tas li ntawd, nws yog ib qho tseem ceeb feem ntawm cov sis plawv hniav zeb. Polyvinyl cawv yog yuav tsum tau builders thiab metallurgists, tanners thiab manufacturers ntawm cov xim tsev thiab varnishes. Tag nrho cov nroj tsuag ua dag fibers yog siv rau qhov siv thiab PVA, uas muab lawv lub dag lub zog los ntawm ib tug txheej txheem ntawm sizing fibers.

Txawm xws li ib tug science ntawm microbiology tau siv PVA nyob rau hauv lub immobilization ntawm enzymes thiab hlwb. Polyvinyl cawv thiab pom daim ntawv thov nyob rau hauv printing, nyob rau hauv particular screen printing. Nyob rau hauv daim teb no nws yog siv raws li ib tug polymer txheej rau cov luam txoj kev. Nws yuav siv tau kuj raws li ib tug ntim los yog kev tiv thaiv cov ntaub ntawv uas nyob rau hauv zus tau tej cov txheej Cheebtsam vim lub fact tias ib tug txheej ntawm PVA yog yooj yim muab tshem tawm.

Raug kev lag luam thiab thov pwm kuj yog siv nrog kev vam meej, qhov no polymer. PVA yog tam sim no ua ntau ntau nyob rau hauv kev khwv nyiaj txiag. Nws yog muaj nyob rau ntawm ib tug nqi uas yog ib qho yooj yim mus thauj (feem ntau yog nyob rau hauv hnab yas, tau ntim rau hauv hnab ntawv) nyob rau hauv ib tug kaw thauj nyob rau hauv kom tsis txhob tau txais ntub. Txij li thaum lub polyvinyl cawv yog flammable, nws yog tsim nyog los ua raws li kev ruaj ntseg cov kev cai lub sij hawm cia thiab tuav.