Thermal degradation behavior of polymethacrylates containing amine side groups

The thermal degradation behavior of polymethacrylates containing amine groups such as poly(N,N-diethyl aminoethyl methacrylate), PDEAEM, and poly(N-ethyl-m-tolyl-aminoethyl methacrylate), PMEET, has been studied using thermogravimetry coupled with infrared spectroscopy (TGA/FTIR). PDEAEM showed two degradation stages whereas PMEET displayed only one. The thermal degradation of PDEAEM initially takes place through ester cleavage of the polymethacrylate, generating volatile tertiary amines and alcohols and polymethacrylic anhydride in the remaining solid material. This is followed by further fragmentation of the modified polymeric chain formed. It was also observed that storage of the original polymer affected the thermal decomposition behavior of PDEAEM. The main thermal degradation pathway for PMEET is an immediate backbone chain scission to yield oligomers.