which the R1 substituent independently for each position is H or an alkyl group having 1 to 5 carbon atoms, R8 is a linear or branched chain alkyl or alkylene oxy having 1 to 20 carbon atoms, R4 substituent independently for each position is an alkyl group having 1 to 5 carbon atoms or an aryl group, e and g are independently 1 to 10, and f is 1 to 50. 2.