1-Piperazineethanamine, polymer with 2,2'-((1-methylethylidene)bis(4,1-phenyleneoxymethylene))bis(oxirane) 110813-95-1 117548-31-9 2,2'-((1-Methylethylidene)bis(4,1-phenyleneoxymethylene))bis(oxirane) 2-aminoethyl-1-piperazine polymer 70776-37-3