Introduction of Carbonyl Group to the Main Chain of Poly(pheny1 Vinyl Sulfide)
Recently, much attention has been focused on the degradation of polymers. The representative photodegradation polymer is the material containing carbonyl group which absorbs the light of ultraviolet region. The degradation mechanisms of these polymers have been studied in The methods of the preparation of such polymers have been widely investigated, but most of them were prepared from the copolymerization of vinyl ketones,13 methyl methacrylate: and carbon monoxide5 with other vinyl monomers. As a series of the reaction of sulfide polymer,-we report here one of the examples for preparing ketone polymer by the use of poly(pheny1 vinyl sulfide) (PPVS) as a starting material.
There are many reports on the conversion of organic sulfur compounds to carbonyl c o m p o ~n d s . ~ Several years ago, Bakuzis et a L I O succeeded in preparing aldehydes by the chlorination of phenyl alkylsulfides followed by oxidation:
If an a-proton of alkyl phenyl sulfide in eq. ( ) is replaced with an alkyl group, the structure of the resulting sulfide is the same as the structure of PPVS. From this viewpoint, we expected that PPVS could be converted to the polymer containing carbonyl group to the main chain of the polymer.
EXPERIMENTAL Preparation of PPVS (I)
PPVS was prepared by the same procedure as described previous1y.l'
Chlorination of PPVS (I)
Method A: A solution of PPVS (10.88 g) and N-chlorosuccinimide (10.86 g) in 400 mL of benzene was refluxed under nitrogen for 6 h. After cooling, the mixture was filtered, and the solvent was removed under reduced pressure. The crude polymer was purified by the reprecipitation with benzene-methanol and was dried. The yield was 10.16 g. ANAL: C1,28.18%.
Method Bc A solution of PPVS (1.36 g) and t-butyl hypochlorite (1.09 g) in 30 mL of benzene was irradiated by 60-W tungsten lamp with a 10-cm path length for 2 h under nitrogen. After evaporation of the solvent, the crude polymer was purified by reprecipitation with benzene-methanol. The yield was 1.15 g.
Oxidation of Chlorinated PPVS (11)
Chlorinated PPVS (4.6 g), acetone (140 mL), CuClz (9.3 g), CuO (9.3 g), and water (3 mL) were placed in a three-necked flask. The mixture was refluxed with stirring for 6 h. After cooling, the product was extracted with benzene and dried. Evaporation of the solvent gave crude oxidized polymer. This polymer was purified by reprecipitation with benzene and petroleum ether. The yield was 1.73 g.