摘要
采用反相气相色谱技术,将正己烷、正庚烷、正辛烷、正壬烷作为非极性分子探针,乙醚、丙酮、三氯甲烷作为极性分子探针在50℃、60℃、70℃和80℃条件下测定了可溶性聚酰亚胺HQDPA-DMMDA的表面色散自由能与表面Lewis酸碱性质.HQDPA-DMMDA在50℃、60℃、70℃和80℃的表面色散自由能分别为34.37、31.80、29.50和27.64 mJ/m2,自由能随温度的升高而线性降低.实验发现,HQDPA-DMMDA为弱的Lewis两性聚合物材料,其Lewis酸常数Ka为0.4115,碱常数Kb为0.5812.
Inverse gas chromatography （IGC） is a new characterizing method for surface properties in polymer field. The main difference between GC and IGC is that the interested species is the polymer material acting as the stationary phase in IGC column. Probe solvents with known properties are injected in column. For the interactions between probe solvents and polymer stationary phase are different, the surface properties of polymer can be determined from the retention volume of probe solvents. In this work, surface properties of soluble polyimide HQDPA- DMMDA were quantitatively analyzed by the IGC method. Four n-alkanes （C6, C7, C8 and C9 ） were chosen as nonpolar probes to characterize the dispersive component of free energy. Trichloromethane （CHCl3）, ethyl ether and acetone were chosen as polar probes to detect the Lewis acid-base parameters. It was found the dispersive component of free energy of HQDPA-DMMDA was 34.37 mJ/m^2 ,31.80 mJ/m^2 ,29.50 mJ/m^2 and 27.64 mJ/m^2 at 50℃ ,60℃, 70℃ and 80℃, respectively. The surface free energy decreased linearly with increasing temperature. The Lewis acidic number Ka of HQDPA-DMMDA was 0.4115, and basic number Kb was 0.5812. The result meant that HQDPA-DMMDA was a weak Lewis amphoteric polymer.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2007年第6期509-513,共5页
Acta Polymerica Sinica
基金
东北林业大学引进人才创新项目和973项目(项目号2003CB615704)
关键词
反相色谱
表面自由能
酸碱性质
聚酰亚胺
Inverse gas chromatography, Surface free energy, Acid-base properties, Polyimide
