Synthesis and characterization of isoprene based homo and copolymers by PECVD technique

In this study, poly (Isoprene) and poly (Isoprene-co-Acrylic acid) polymeric thin films were synthesized by Plasma Assisted Chemical Vapor Deposition (PECVD) method. The PECVD method was preferred for the synthesis of desired homo and copolymer thin films, since it offers important advantages such as coating in one step and at low temperature without the need for solvent use. In experimental studies, the effects of changes in monomer flow rates on the chemical, morphological and wetting properties of the coatings were investigated by keeping the substrate temperature and plasma power parameters constant. Thin film coatings on silicon substrate were obtained by feeding 2-methyl 1,3-butadiene (Isoprene) and acrylic acid (AA) monomer vapors to the PECVD reactor without any heating processes. 13.56 MHz RF plasma source was used in the system and 15 W plasma power was applied in the experimental studies. When the FTIR spectra of the coated films were examined, it was observed that the functional groups were largely protected and chemically uniform, hydrophilic copolymer films were obtained. It has been observed that the PIP homopolymer coating is the most homogeneous and pin hole-free coating, the PAA coating contains a small amount of pinholes, and the P(AA-IP) copolymer coating surface contains a large number of pinholes of different sizes spread over the entire surface. According to the AFM results, very smooth P (IP-AA) thin films with a roughness of 5.9 nm were obtained.