Thermal and mechanical properties of polysulfide/epoxy copolymer system: the effect of anhydride content

• Published in: Polymers for advanced technologies Vol. 25; no. 2; pp. 184 - 190
• Main Authors: Soroush, Adel, Rezaie Haghighat, Hasan, Sajadinia, Seyed Hosein
• Format: Journal Article
• Language: English
• Published: Chichester Blackwell Publishing Ltd 01.02.2014; Wiley; Wiley Subscription Services, Inc
• Subjects: anhydride; Anhydrides; Applied sciences; Chemical properties; epoxy resin; Exact sciences and technology; mechanical properties; Polymer industry, paints, wood; polysulfide; Properties and testing; Technology of polymers; thermal properties; Polymer blends; Liquid rubber; Epoxy resin; Mechanical properties; polysulfide; Organic anhydride; Curing (plastics); Experimental study; Property processing relationship; Tensile strength; Thermal stability; Sulfide copolymer; Thermal properties; Experimental design; anhydride; Concentration effect; Reaction mechanism
• ISSN: 1042-7147; 1099-1581
• DOI: 10.1002/pat.3221

Polymerization of a ternary system containing polysulfide (PS), as a liquid elastomer, diglycidylether of bisphenol A resin, and phthalic anhydride was conducted using “design of experiment” technique. The polymerization progress with respect to concentration variations of components were studied by Fourier transform infrared spectroscopy. Fourier transform infrared spectroscopy studies showed that the anhydride plays a decisive role in curing reaction so that, in its absence, the epoxy/PS mixture becomes gel in about 2 hr, whereas, by addition of the anhydride, the pot life of the system can be extended to 48 hr. The cured samples were investigated by thermal gravimetry analysis and differential scanning calorimetry to evaluate thermal properties. Thermal gravimetry analysis and differential scanning calorimetry results indicated that two different soft and hard segments are formed, which have different thermal decompositions. The soft segment consists of loose etheric bonds, which are attributed to PS, and the hard segment is formed during the etherification and esterification reactions of the epoxy resin. Tensile strength test was performed to investigate the mechanical properties of PS/epoxy/anhydride‐cured systems. The results showed that the tensile strength, elongation‐at‐break, and the fracture energy of specimens are essentially dependent on PS/anhydride ratios. Two different segments impart high strength and ductility simultaneously. Copyright © 2013 John Wiley & Sons, Ltd.