UV and Visible Light Photoinduced Polymerization of Pyrrole/Methacrylate.

ASMUSSEN, SILVANA V.; CLAUDIA I. VALLO

Pyrrole: Synthesis and Applications

Nova Science Publishers, Inc.

Lugar: Hauppauge; Año: 2020; p. 71 - 98

Electrically-conducting polymers such as polypyrrole have been the focus of intense research interest over the last ten decades because they can be used in a wide range of technologies. However, it is well established that electrically-conducting polymers fabricated by chemical or electrochemical polymerization processes are either powders or intractable polymers which exhibit deficient mechanical properties and are difficult to process. A possible way of improving the mechanical properties of polypyrrole is by mixing it with other polymers in order to reach a synergetic overall performance. In this study pyrrole was blended with a methacrylate resin and the mixtures were processed by photopolymerization. This polymer processing method has the advantage that permits the incorporation of different additives and flexibilizers into the resins thereby optimizing its manufacture and improving the mechanical properties of the final cured material. The photoinitiator systems used to cure the mixtures pyrrole/methacrylate consisted of the iodonium salt p-(Octyloxyphenyl)phenyliodonium hexafluoroantimonate (IODS), in combination with Benzil α,α-dimethyl acetal (BDMA), α-Methoxy-α-phenylacetophenone (MPAP) or the pair camphorquinone (CQ)/ethyl-4-dimethylamino benzoate (EDMB). Mixtures photoactivated with the IODS salt in combination with BDMA or MPAP were efficiently cured under UV irradiation (λ=365 nm). On the other hand, in mixtures photoactivated with IODS/CQ/EDMB and irradiated with visible light ((λ=470 nm) thepolymerization of both methacrylate and pyrrole was much slower. Scanning electron microscopy studies showed no sign of phase separation demonstrating that the pyrrole/methacrylate blends formed an interpenetrating network. Studies of electrical properties of the hybrid polymers revealed that their electrical conductivity increased markedly with the proportion of pyrrole in the initial mixture. This is attributed to the formation of an electrically conducting polymer network in the non-conducting methacrylate matrix.