Product analysis, electrical and dielectric properties depending on thermal influence of poly(N-isopropyl acrylamide)/graphite-filled composite

• Published in: Thermochimica acta Vol. 669; pp. 66 - 79
• Main Authors: Biryan, Fatih, Abubakar, Abdullahi Musa, Demirelli, Kadir
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10-11-2018
• Subjects: Dielectric properties; Poly(NIPAM); Thermal degradation; Dielectric properties; Poly(NIPAM); Thermal degradation
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2018.09.009

•Poly(NIPAM)/8% by wt graphite-filled composite was prepared.•Thermal degradation and electrical behaviors of PNIPAM and composite have been investigated.•Electrical properties of composite were greatly improved by the addition of graphite.•When composite was compared to PNIPAM, formation of N-isopropylacrylamide increased from 9% to 25%.•A mechanism on formation of major evolved products has been submitted.
The ac dielectric and electrical behaviors of the pure poly(N-isopropylacrylamide) (PNIPAM) and PNIPAM/8% by wt graphite-filled composite at room temperature and that of partially degraded polymer were investigated. TGA measurements showed that thermal degradation of the pure PNIPAM and PNIPAM/8% by wt graphite-filled composite polymers were a single-stage process under nitrogen atmosphere. Phenomenon of depolymerization from thermal degradation of PNIPAM and PNIPAM/8% by wt graphite-filled composite was revealed as a significant difference in comparison to polyacrylamide and other analogous. In degradation studies, while the N-isopropylacrylamide was detected as 25% by mole among products of degradation of PNIPAM/8% graphite-filled composite, this event was 9% by mole for that of pure PNIPMA. The major evolved products were found to be molecules such as N-isopropylacrylamide, cyclic-imides, diisopropylamine, dimer and trimer. Degradation mechanism of the polymer was briefly suggested and evaluated the relationship between structures of the pure PNIPAM and PNIPAM/8% graphite-filled composite polymers.