Physicochemical Cov Khoom Ntawm Pvc
Dec 23, 2022| PVC yog yellowish thiab translucent nrog luster. Transparency yog zoo dua li polyethylene thiab polypropylene, thiab phem dua li polystyrene. Nws tuaj yeem muab faib ua mos thiab tawv polyvinyl chloride raws li tus nqi ntawm cov khoom ntxiv. Cov khoom muag muag yog mos thiab tawv, thiab xav tias nplaum. Lub hardness ntawm cov khoom tawv yog siab dua li ntawm cov polyethylene tsawg, tab sis qis dua li ntawm polypropylene. Whitening yuav tshwm sim ntawm qhov khoov. ruaj khov; Nws tsis yooj yim rau corroded los ntawm acid thiab alkali; Nws kuj yog resistant rau tshav kub.
PVC muaj qhov zoo ntawm cov nplaim hluav taws kub nyhiab (tus nqi nplaim hluav taws kub siab tshaj 40), cov tshuaj tiv thaiv siab (ua haujlwm rau cov concentrated hydrochloric acid, sulfuric acid nrog concentration ntawm 90 feem pua, nitric acid nrog concentration ntawm 60 feem pua thiab sodium hydroxide nrog concentration ntawm 20 feem pua) , zoo mechanical zog thiab hluav taws xob rwb thaiv tsev.
PVC muaj qhov tsis zoo rau lub teeb thiab cua sov. Lub softening point yog 80 degree, thiab lub decomposition pib ntawm 130 degree. Tsis muaj cua sov lub stabilizer, PVC pib decompose ntawm 100 degree thiab decomposes sai dua 130 degree. Thaum rhuab, hydrogen chloride gas (hydrogen chloride gas yog cov pa roj lom) yog decomposed kom nws hloov xim ntawm dawb → teeb daj → liab → xim av → dub. Cov hluav taws xob ultraviolet thiab cov pa oxygen hauv lub hnub ci yuav ua rau cov duab oxidation decomposition ntawm PVC, yog li txo qhov yooj ntawm PVC thiab thaum kawg ua rau nws nkig. Qhov no yog vim li cas qee cov PVC yas yuav tig daj thiab nkig tom qab ntev.
Lub cev ruaj khov thiab tshuaj lom neeg, insoluble hauv dej, cawv thiab roj av, tsis tshua muaj roj thiab dej vapor to; Nyob rau hauv ib txwm kub, nws muaj peev xwm tiv taus ib qho concentration ntawm hydrochloric acid, tsawg dua 90 feem pua sulfuric acid, 50-60 feem pua nitric acid thiab tsawg dua 20 feem pua caustic soda tov, thiab muaj tej yam tshuaj corrosion kuj; Nws yog qhov ruaj khov rau cov ntsev, tab sis tuaj yeem yaj hauv cov kuab tshuaj organic xws li ether, ketone, chlorinated aliphatic hydrocarbon thiab aromatic hydrocarbon.
Muaj PVC resin feem ntau yog amorphous qauv, tab sis kuj muaj qee qhov chaw crystalline (kwv yees li 5 feem pua), yog li PVC tsis muaj qhov pom tseeb melting point. Nws pib soften ntawm li 80 degree , thiab thermal deformation kub (hauv qab 1.82MPa load) yog 70-71 degree . Nws pib ntws ntawm 150 degree nyob rau hauv siab, thiab maj mam tso tawm hydrogen chloride, ua rau PVC hloov xim (los ntawm daj mus rau liab, xim av, los yog txawm dub).
Qhov hnyav nruab nrab tus txheeb ze molecular hnyav ntawm kev lag luam PVC yog li ntawm 48000 txog 48000, thiab tus lej sib thooj nruab nrab tus txheeb ze molecular hnyav yog 2-19500. Qhov hnyav nruab nrab tus txheeb ze molecular hnyav ntawm feem ntau cov khoom siv resins yog nyob nruab nrab ntawm 100000 thiab 200000, thiab tus lej nruab nrab tus txheeb ze molecular hnyav yog nyob nruab nrab ntawm 45500 thiab 64000. Rigid polyvinyl chloride (tsis muaj plasticizer) muaj lub zog zoo txhua yam, huab cua tsis kam thiab nplaim taws. Nws tuaj yeem siv los ua cov khoom siv ib leeg thiab siv hauv kev lag luam tshuaj los tsim cov kav dej, daim hlau thiab cov khoom txhaj tshuaj molded. Rigid PVC tuaj yeem txhawb nqa.