아세토페논을 함유한 Poly(phenylene sulfide)의 광가교에 의한 내열성과 인장인성 강화

Abstract

Poly(phenylene sulfide) films containing acetophenone as a photoinitiator were photocrosslinked under UV irradiation using a continuous UV irradiator. The gel fraction of the irradiated PPS in 1-Chloro naphthalene reached 94.7%with increasing UV energy and the photoinitiator concentration in the film upto 200J/cm2 and 12wt% respectively. Solid state 1C NMR analysis suggested that the crosslinking occurred between the phenylene chains in PPS, indicating that the acetophenone may abstract the phenylene hydrogens and subsequently adjacent polymer radicals could be recombined to form the crosslinked structure. The crosslinking improved the thermal behavior of PPS such as loss of Tg and Tc, higher melting point and lower melting enthalphy as well as significantly higher peak pyrolysis temperature as much as 63.5oC. Surprisingly the tensile toughness of the most crosslinked PPS increased by 842%, resulting from the substantial enhancements in tensile modulus, strength and strain as much as 76%, 236% and 240% respectively. Also dynamic mechanical measurement indicated that the distance between crosslinks in the crosslinked PPS reached 85.3 g/mol corresponing to a crosslink density of 0.012 mol/g.