of fields including the areas of sanitation and nutrition moreover they are simple to prepare under relatively mild conditions on existing equipment and with readily available materials in order to illustrate the present invention more fully the following examples are set forth it is to be understood that the examples are illustrative and not limitative in the examples and the appended claims all parts proportions and percentages are by weight unless otherwise stated solutions of 0 083 gram of benzoyl peroxide in 3 grams of styrene and 0 051 gram of poly p dimethylaminostyrene in 3 2 grams of styrene were mixed together in glass ampoules having two arms and which had been previously flushed with nitrogen sealed and placed into a bath maintained at the constant temperature of 20 u00b0 c the mixture was thick and gelatinous after 1 hour and when precipitated with methanol formed a hard slightly yellowish polymer it had a number average molecular weight of 45 000 and was suitable for use as block or powder polystyrene solutions of 0 088 gram of benzoyl peroxide in 3 grams of chloroprene and 0 054 gram of poly p dimethylaminostyrene in 4 grams of chloroprene were mixed and further.