Damping materials based on plasticized polybutyl methacrylate, polymethyl methacrylate and polyvinyl acetate

The purpose of the presented work is to investigate by DMA method the influence of the composition of filled and unfilled plasticized compositions based on polyvinyl acetate (PVA), polybutyl methacrylate (PBMA) and polymethyl methacrylate (PMMA) on their damping characteristics. It was found that when plasticizer is introduced into the polymer, the value of the mechanical loss coefficient first increases, reaches its maximum, and begins to decrease with further increase in the plasticizer content. The maximum effect is observed at a plasticizer/polymer volume ratio of 0.2-0.4. Two other dissipative characteristics, the temperature interval of effective damping and the integral coefficient of mechanical losses, are changing similarly. It is established that the additives of chlorinated paraffins in compositions based on PVA and PBMA can significantly improve their vibration absorbing characteristics. Introduction of mica filler into the composition of plasticized compositions based on PVA and PBMA does not lead to the appearаnсe of additional relaxation mechanisms. With increasing of the content of mica, the elastic modulus of compositions increases in the entire temperature range (especially significantly for compositions with a high content of plasticizer), the coefficient of mechanical losses slightly decreases, and the temperature practically does not change at which the maximum damping is observed.