Kuora kwePVC kunonyanya kukonzerwa nekuora kwemaatomu echlorine ari mumorekuru iri kudziya uye okisijeni, zvichikonzera kugadzirwa kweHCI. Saka, zvinodzivirira kupisa zvePVC zvinonyanya kuve makemikari anogona kudzikamisa maatomu echlorine mumamorekuru ePVC uye kudzivirira kana kugamuchira kuburitswa kweHCI. R. Gachter et al. vakaronga mhedzisiro yezvinodzivirira kupisa senzira yekudzivirira uye yekugadzirisa. Yekutanga ine mabasa ekunyudza HCI, kutsiva maatomu echlorine asina kugadzikana, kubvisa masosi ekupisa, uye kudzivirira otomatiki oxidation. Yekupedzisira mhando yekugadzirisa inovavarira kuwedzera kune chimiro chepolyene, kuita nezvikamu zvisina kuguta muPVC, uye kuparadza carbocations. Kunyanya, seizvi:
(1) Kunwisa HC1 yakatorwa kubva kuPVC kudzivirira kushanda kwayo kwega. Zvigadzirwa zvakaita semunyu we lead, sipo dzesimbi dze organic acid, makemikari e organotin, makemikari e epoxy, amines, metal alkoxides uye phenols, uye simbi thiols zvese zvinogona kuita neHCI kudzivirira kuita kwe deHCI kwePVC.
Ini (RCOO) 2+2HCI MeCl+2RCOOH
(2) Tsiva kana kubvisa zvinhu zvisina kugadzikana zvakaita semaatomu eallyl chloride kana maatomu e tertiary carbon chloride mumamorekuru ePVC, uye bvisa nzvimbo yekutanga yekubvisa HCI. Kana maatomu etin eorganic tin stabilizers achibatana nemaatomu echlorine asina kugadzikana emamorekuru ePVC, uye maatomu esulfur ari muorganic tin achibatana nemaatomu ecarbon anoenderana muPVC, maatomu esulfur ari mumuviri wekubatana anotsiva nemaatomu echlorine asina kugadzikana. Kana HC1 iripo, coordination bond inotsemuka, uye hydrophobic group inobatanidzwa zvakasimba nemaatomu ecarbon ari mumamorekuru ePVC, nokudaro zvichidzivisa mamwe maitiro ekubvisa HCI uye kuumbwa kwedouble bonds. Pakati pesipo dzesimbi, zinc sipo nesipo yepoto zvine constant replacement reaction neatomu dzechlorine dzisina kugadzikana, barium sipo ndiyo inononoka, calcium sipo inononoka, uye lead sipo iri pakati. Panguva imwe chete, ma chloride esimbi anogadzirwa ane madhigirii akasiyana e catalytic effect pakubviswa kweHCI, uye simba rawo nderinotevera:
ZnCl>CdCl>>BaCl, CaCh>R2SnCl2 (3) inowedzerwa ku double bonds uye co conjugated double bonds kudzivirira kukura kwe polyene structures uye kuderedza coloring. Unsaturated acid salts kana complexes dzine double bonds, iyo inopinda diene addition reaction nema PVC molecules, nokudaro ichikanganisa covalent structure yavo uye ichidzivisa kuchinja kwemavara. Pamusoro pezvo, sipo yesimbi inoperekedzwa ne double bond transfer uku ichitsiva allyl chloride, zvichikonzera kukuvara kwe polyene structure uye nokudaro zvichidzivisa kuchinja kwemavara.
(4) Bata mafree radicals kudzivirira otomatiki oxidation. Kana kuwedzera phenolic heat stabilizers kuchigona kudzivirira kubviswa kweHC1, imhaka yekuti hydrogen atomu free radicals inopiwa nemaphenols inogona kusanganiswa nemaPVC macromolecular free radicals akaora, zvichigadzira chinhu chisingagone kuita neokisijeni uye chine simba rekupisa. Ichi chinodzora kupisa chinogona kuva nemhedzisiro imwe kana dzakawanda.
Nguva yekutumira: Kurume-29-2024
