KINETIC'S INVESTIGATION OF METHACRYLIC MONOMERS BASED ON 2-STYRYLQUINOLINE

DOI: https://doi.org/10.17721/1728-2209.2019.1(56).10

Abstract

Polymethylmethacrylate is widely use material in optics due to its atmosphere resistance, chemical stability, good mechanical properties, transparency and light transmission. Due to these properties, PMMA is often used as a polymeric matrix for creating photosensitive polymers and polymers with nonlinear optical (NLO) properties. Materials with NLO properties can be made by introducing moleculas of chromophores into the polymer chain. There are two fundamentally different ways of doing this. The first is to create composite material where the chromophore is a dispersed phase and is introduced into the system as a "guest". In the second case, the chromophore is introduced into the polymer chain covalently, and can be included in the side and the main chain. Studies of polymers containing NLO chromophore in the side chain have shown a number of advantages: better orientation of the chromophores under the action of an electric field; relaxation processes are much slower; increasing time and thermal stability; increasing the glass transition temperature of the polymer. Based on present knowledge we decided to design new methacrylic polymers with styrylquinoline chromophore in side chain.

The polymerization ability of the new monomers for free radical homopolymerization was investigated kinetically by using dilatometric method. It was found that new 2-styrylquinoline containing monomers are able to homopolymerization with high conversions (63–83 %). The polymerization was carried out in DMF using 2,2´-azobisisobutyronitrile as initiator at 80°C in argon atmosphere. The products of polymerization were characterized by ¹H NMR spectroscopy. It was installed that all new monomers have bigger speed of polymerization (K_sum= 1.36–8.33×10³ l/mol×s) then methylmethacrylate (K_sum= 0.5×10³ l/mol×s), phenylmethacrylate (K_sum= 1.1×10³ l/mol×s) and similar to polymerization of 2-methyl-8-oxyquinoline methacrylate (K_sum= 3.28×10³ l/mol×s). It was found that speed of polymerization increases with increasing electron donating power of substitute in para-position of the aromatic ring. It has been proven that presence of electron acceptor group reduces speed of polymerization.