The use of positron annihilation to study polyacrylamide and polymethylmethacrylate-Alcohols and diols mixture

The effect of addition of both alcohols and diols to polyacrylamide (PAA) and polymethylmethacrylate (PMMA) forming polymer mixtures was studied using positron annihilation lifetime (PAL) and Doppler broadening of annihilation radiation (DBAR) techniques. It was found that, by increasing chain length of alcohols, PAA-alcohols contain free volume with small size V and low fraction f, while PMMA-alcohols contain free volume with large size and high fraction. On the other hand, S-parameter increases and W-parameter decreases in PAA-diols according to the number of carbon and hydrogen atoms in the chain. In addition, the electrical conductivity measurements are performed on the above two polymer mixtures. The results showed that both PAA and PMMA exhibit semiconducting properties by the addition of alcohols and diols. Correlation between the macroscopic conductivity properties and the microstructures such as free volume and microdefects are established.