Phthalic Anhydride PH

Phthalic anhydride (PA) nrog cov tshuaj formula C8H4O3. Nws yog muab los ntawm oxidation ntawm ortho-xylene los yog naphthalene. PA yog siv dav hauv kev lag luam tshuaj rau kev tsim khoom ntawm ntau yam khoom, suav nrog cov yas yas, polyester resins, dyes, thiab tshuaj.

Thaum nws los txog rau phthalic anhydride pH, Phthalic anhydride nws tus kheej yog cov khoom sib xyaw thiab tsis muaj pH tus nqi. pH yog ib qho kev ntsuas ntawm acidity los yog alkalinity ntawm cov kua aqueous. Txawm li cas los xij, PA tuaj yeem cuam tshuam nrog dej los tsim phthalic acid, uas yog acidic hauv xwm.

Cov tshuaj tiv thaiv ntawm phthalic anhydride nrog dej tuaj yeem sawv cev raws li hauv qab no:
C8H4O3 + H2O → C6H4(COOH)2

Cov txiaj ntsig phthalic acid, C6H4 (COOH) 2, tuaj yeem sib cais hauv dej kom tso cov hydrogen ions (H +), uas ua rau cov kua qaub ntawm cov tshuaj. Yog li, pH ntawm cov tshuaj uas muaj phthalic acid yuav nyob ntawm qhov concentration ntawm phthalic acid thiab dissociation ntawm nws cov acidic functional pawg.

Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias pH ntawm cov tshuaj uas muaj phthalic anhydride los yog phthalic acid tuaj yeem cuam tshuam los ntawm lwm yam, xws li muaj lwm yam tshuaj los yog buffers. Tsis tas li ntawd, pH ntawm cov tshuaj tuaj yeem sib txawv nyob ntawm qhov concentration ntawm cov kua qaub thiab muaj lwm cov kua qaub lossis cov hauv paus hauv lub cev.

Hauv cov ntsiab lus, thaum phthalic anhydride nws tus kheej tsis muaj pH tus nqi, nws cov khoom siv hydrolysis, phthalic acid tuaj yeem ua rau cov kua qaub ntawm cov kua qaub, thiab pH yuav nyob ntawm qhov concentration ntawm phthalic acid thiab lwm yam hauv lub cev.