Synthesis and characterization of poly(ether sulfone) copolymers

✍ Scribed by V. Lakshmana Rao; M. Rama Rao

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 191 KB
• Volume: 69
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980725)69:4<743::aid-app12>3.0.co;2-q

✦ Synopsis

Poly(ether sulfone) copolymers I-V were synthesized by the nucleophilic substitution reaction of 4,4-dichlorodiphenyl sulfone with varying mole proportions of 4,4-isopropylidene diphenol (bisphenol A) and 4,4-dihydroxydiphenyl sulfone (bisphenol S) using sulfolane as the solvent in the presence of anhydrous K 2 CO 3 . The polymers were characterized by different physicochemical techniques. The glass transition temperature was found to decrease with increase in the concentration of bisphenol A units in the polymers. All polymers were found to be amorphous. Thermogravimetric studies showed that all the polymers were stable up to 400ЊC with a char yield of about 36% at 900ЊC in a nitrogen atmosphere. 13 C-NMR spectral analysis reveals that bisphenol S-based triads are preferentially formed compared to bisphenol-A triads, indicating greater reactivity of bisphenol S toward dichlorodiphenyl sulfone. The overall activation energy for the thermal decomposition of bisphenol A-based polymer (1) is much higher than that of bisphenol S-based polymer (II). This was attributed to the modification of the backbone of polymer I during the initial cleavage of the C{CH3 bond of the isopropyledene group. Polymer II decomposes by cleavage of the C{SO2 bond.