聚芳醚酮分子结构、极化及分子量的谱学研究

聚芳醚酮在硫酸溶液中产生极化的主要因素包括质子化作用,硫酸的各种作用表明:聚合物分子结构中酮基含量或分子链刚性度增加时,硫酸的极化作用也增加,表现为UV谱红移,最大吸收峰显著增强及测得粘度与实际植偏差增大.由此,首次提出粘度法测定分子量时应考虑分子刚性等的影响.而用¹⁹F NMR法对合成的大量聚芳醚酮化合物分子量的定量研究表明,此法可由测得的端基氟含量,进而得到高聚物的数均分子量,无需校正.

MOLECULAR STRUCTURE,POLARIZATION AND MOLECULAR WEIGHTS FOR POLY (ARYL ETHER KETONE)s BY UV ~(19)F NMR METHODS

Protonation is one of the major factors for poly(aryl ether ketone)_s (PAED_s) molecules polarized in H₂SO₄. Results from UV and calculation show that degree of polarization of PAEK_s by H₂SO₄ increases with the ketone content or molecular chain regidity in polymer chains. This has been further proved by the experimental results, such as, larger λ_max (UV), more intense absorption at λ_max and greater deviatiou between experimental and practical viscosity values in concentrated H₂SO₄ than in other solvents. Based on these, we firstly suggested that the molecular rigidity is an important factor tobe considered in measuring the PAEK_s molecularweights. While, ¹⁹F NMR is adopted to quantitatively measure the molecular weight of many synthesized oligomers aud polymers, which gives a number-average molecular weights without any correction.