A na-ebute mmebi nke PVC site na nbibi nke atom chlorine na-arụ ọrụ na molekul n'okpuru kpo oku na ikuku oxygen, na-ebute mmepụta nke HCI. Ya mere, PVC okpomọkụ stabilizers bụ tumadi ogige nwere ike kwụsie ike na chlorine atom na PVC molekul ma gbochie ma ọ bụ nabata ntọhapụ nke HCI. R. Gachter et al. nkewa mmetụta nke okpomọkụ stabilizers dị ka mgbochi na remedial. Nke mbụ nwere ọrụ nke ịmịkọrọ HCI, dochie atọm chlorine na-adịghị akwụsi ike, na-ewepụ isi mmalite mgbanye, na igbochi oxidation akpaka. Ụdị mmezi nke ikpeazụ a na-achọ ịgbakwunye na nhazi polyene, meghachi omume na akụkụ ndị na-adịghị mma na PVC, ma bibie carbocation. Kpọmkwem, dị ka ndị a:
(1) Absorb HC1 ewepụtara na PVC iji gbochie ọrụ catalytic onwe ya. Ngwaahịa dị ka nnu nnu, ncha metal acid organic, ogige organotin, ogige epoxy, amines, metal alkoxides na phenols, na thiols metal nwere ike meghachi omume na HCI iji gbochie mmeghachi omume HCI nke PVC.
Mụ (RCOO) 2+2HCI MeCl+2RCOOH
(2) Dochie ma ọ bụ kpochapụ ihe ndị na-adịghị akwụsi ike dị ka atom chloride allyl ma ọ bụ atọm carbon chloride atom n'ime ụmụ irighiri ihe PVC, ma kpochapụ ebe mmalite nke mwepụ HCI. Ọ bụrụ na tin atom nke organic tin stabilizers na-ahazi na atom chlorine na-adịghị akwụsi ike nke ụmụ irighiri ihe nke PVC, yana sọlfọ atom na tin organic na-ejikọta ya na carbon carbon kwekọrọ na PVC, atom sọlfọ dị na ahụ nhazi na-eji atom chlorine na-adịghị akwụsi ike dochie. Mgbe HC1 dị, njikọ nchikota na-ekewa, na otu hydrophobic na-ejikọta ya na carbon carbon na molecule PVC, si otú a na-egbochi mmeghachi omume ọzọ nke mwepụ HCI na ịmepụta nkekọ abụọ. N'ime ncha ọla, ncha zinc na ncha ite nwere mmeghachi omume ngbanwe kachasị ngwa ngwa na atom chlorine anaghị akwụsi ike, ncha barium na-adị nwayọ, ncha calcium na-eji nwayọ nwayọ, na ncha ndu dị n'etiti. N'otu oge ahụ, chloride metal emepụta nwere ogo dị iche iche nke catalytic mmetụta na mwepụ nke HCI, na ike ha bụ dị ka ndị a:
A na-agbakwunye ZnCl> CdCl>> BaCl, CaCh> R2SnCl2 (3) na nkekọ abụọ na njikọ njikọ abụọ iji gbochie mmepe nke ihe owuwu polyene ma belata agba. Acid salts ma ọ bụ ogige ndị na-adịghị mma nwere njikọ abụọ, nke na-enweta mmeghachi omume mgbakwunye diene na ụmụ irighiri ihe PVC, si otú a na-akpaghasị nhazi ha na-egbochi mgbanwe agba. Na mgbakwunye, ncha ígwè na-esonyere ya na nnyefe njikọ abụọ mgbe ọ na-edochi allyl chloride, na-emebi ihe owuwu polyene ma si otú a na-egbochi mgbanwe agba.
(4) Weghara free radicals iji gbochie akpaka oxidation. Ọ bụrụ na ịgbakwunye phenolic okpomọkụ stabilizers nwere ike igbochi mwepụ nke HC1, ọ bụ n'ihi na hydrogen atom free radicals nyere site phenols nwere ike jikọọ na PVC macromolecular free radicals rụrụ arụ, na-eme ihe na-enweghị ike imeghachi omume na oxygen na-enwe thermal stabilization mmetụta. Nke a okpomọkụ stabilizer nwere ike inwe otu ma ọ bụ ọtụtụ mmetụta.
Oge nzipu: Mar-29-2024
