Preparation,polymerization and copolymerization of some unsaturated dibutyltin carboxylates

Dibutylchlorotin acrylate (DBCTA), dibutylchlorotin methyl maleate (DBCTM) and dibutylchlorotin cinnamate (DBCTC) were prepared by metathesis reactions between equimolar proportions of dibutyltin dichloride and the corresponding dibutyltin dicarboxylate. The acrylate (DBCTA) was the only monomer to undergo free-radical homopolymerization and gave an insoluble cross-linked polymer of poly(dibutyltin diacrylate) with the expulsion of dibutyltin dichloride. Free-radical copolymerization with methyl acrylate (MA) gave copolymers with DBCTA and DBCTC. The reactivity ratios were respectively: MA, r₁ = 0.81 ± 0.05; DBCTA, r₂ = 0.08 ± 0.04 and MA, r₁ = 2.0 ± 0.35 DBCTC, r₂ = 0 ± 0.2. DBCTM did not copolymerize with methyl acrylate.Attempts at free-radical copolymerizations with vinyl chloride (VC) were only partially successful due to severe inhibition. DBCTM and DBCTC formed very low molecular weight copolymers containing approximately equal amounts of the comonomers. DBCTA copolymer with VC formed a copoly(dibutyltin diacrylate) network structure. However, solubility in acetic acid-d₄ due to an exchange equilibrium allowed an estimate of the reactivity ratio $\text{r}{}_{\mathrm{vc}}\text{≌ 0.17}$ to be obtained by NMR analysis.Three new tetrabutyl-1,3-di(carboxy) distannoxanes (Bu₂SnOCOR]₂O) (R = CHCH₂; C(CH₃)CH₂ and CHCHC₆H₅) were prepared.