裂解气相色谱-质谱法研究聚苯硫醚热分解

Thermal Decomposition of Poly (Phenylene Sulfide) by Pyrolysis Gas Chromatography-Mass Spectroscopy

采用裂解气相色谱一质谱法研究了在350～750℃之间聚苯硫醚（PPS）的裂解行为。350℃时裂解，仅检测到4种裂解产物。随裂解温度上升，裂解产物急剧增加。在750℃时，检测到25种裂解产物，主要特征裂解产物为硫化氢、苯、苯硫醇、1，4-苯二硫醇、二苯硫、二苯并噻吩、1，4-苯二硫醇基苯、噻茚等。聚苯硫醚裂解过程中，发生链剪切作用，由聚合物链断裂成苯硫醇单体、二聚体和三聚体等化合物。裂解过程还会发生重排，环化，次级反应等形成了各种裂解产物。

Pyrolysis of polyphenylene sulfide has been investigated by pyrolysis gas chromatography - mass spectroscopy at different temperatures ranging from 350 ℃ to 750 ℃. Its composition of pyrolysates has been analyzed. At 350 ℃, pyrolysis of molecular chain could take place; four kinds of pyrolysate were only identified. The compositions of pyrolysate were sharply increased with the increase of temperature. Several compounds, namely, hydrogen sulfide, benzene, benzenethiol, 1,4-benzenedithiol, biphenyl sulfide, 2-methyl-2H-naphtho [ 1,8-bc ] thiophene, dibenzothiophene, 3-benzenethioldibenzothiophene, 1,4-benzenedithio-benzene, 1,4-bis（phenyhhio）-benzene and thianthrene could be formed. During pyrolysis of polyphenylene sulfide, polymeric chain scissions took place as a successive removal of the monomer units from the polymeric chain, and the major decomposition products consisted of di- and trimeric chain fragment. The chain scissions were followed by the secondary reactions, which led to a variety of pyrolysates. The cyclic and rearrangement reactions could also take place during pyrolysis.