聚芳醚酮在溶液中的分子构象与分子极化

经从头计算,得到4,4'-二氟苯酮二面角为44°,MES₃二面角为51°;用UV光谱法研究了单分散齐聚物在H₂SO₄中的分子构象与极化,结果表明:H₂SO₄使碳基质子化是产生极化的主要因素之一,由此产生的新吸收峰在λ=400nm左右;极化作用产生的平面构象经重叠后在λ=500nm左右产生另一新的吸收峰.由质子化模型并考虑组态相互作用的计算结果与文献一致.证明了聚芳醚酮高聚物在H₂SO₄中,于400nm左右处产生的峰(UV)为羰基极化的结果,指明在H₂SO₄中测其分子量时应按羰基含量校正.

Conformation and Polarization for Monodisperse Oligomers and Polymers of Poly(aryl ether ketone )s in Solution

By means of ab initio method the dihedral angle of 44° for 4, 4' -difluorobenzophenone and of 51° for MES₃ are obtained.UVspectra frorn monodisperse oligomers and their molecular polarization in H₂SO₄ show that the protonation of H₂SO₄ acting on carbonyl group is one of the major factors of the polarization.The protonation produces a new absorption peak at λ=4OOnm or so (UV); Meanwhile, the overlapping of planar conformation from polarization produces another new absorption peak at λ=500 nm.Based on the protonation model, the configuration interaction(CI) calculation on it is made, the results of which are ln good agreement with those from experiment.All these prove that the absorption peak at λ=4OOnm for poly (aryl ether ketone)s is resulted from carbonyl polarization.Thus, the polymer molecular weight measured in H₂SO₄ should be corrected according to ketone content in the main chain.