STUDIES ON THE EXCIMER FLUORESCENCE OF POLYPHENYL GLYCIDYL ETHER AND POLYNAPHTHYL GLYCIDYL ETHER

Polyphenyl glycidyl ether (PPGE) and polynaphthyl glycidyl ether (PNGE) have beensynthesized by cationic polymerization and their structures characterized by carbon 13 NMRand 1R, etc. The fluorescence spectra of PPGE, PNGE and their corresponding monomersPGE, NGE as model compounds have been studied. In dilute solutions at room temperature,only monomer fluorescence of the chromophore is observed. Comparison between the spectraobtained from dilute solutions, concentrated solutions and solid film shows that there is excimeremission when polymer chains in solution or in film are sufficiently close to each ocher.From the concentration dependence of the excimer emission, further evidence is obtained forthe existence of interchain excimer interaction in these polymers.     

聚苯基缩水甘油醚和聚萘基缩水甘油醚的激基缔合物荧光研究

合成了聚苯基缩水甘油醚(PI)和聚萘基缩水甘油醚(PII),并用¹³C NMR,IR 等方法鉴定了它们的结构。研究了PI,PII及其模型化合物(单体)的荧光光谱,发现它们的稀溶液只存在单分子荧光。从稀溶液—浓溶液—固体的发射光谱的变化可以看出,当高分子相互靠近到一定程度,在长波方向呈现激基缔合物荧光峰。进一步从浓度效应论证了这是高分子链间芳环相互作用的贡献。这一结果对阐明高分子存在链间激基缔合物提供了新的实验依据。     

STUDIES ON THE PERMEABILITY OF P VC/EBBA OVERLAPPED ULTRATHIN COMPOSITE MEMBRANES MODIFIED BY PLASMA-POLYMERIZATION WITH FLUOROCARBON MONOMERS

The PVC/EBBA ultrathin composite membranes with thickness of about 100 nm were prepared by spreading the solution on water surface. The overlapped composite membrane showed a characteristic aggregation structure in which the polymer matrix exists as a three-dimensional spongy network and the liquid crystal domains werc observed. Tne surface modification for the overlapped membranes was carried out by means of plasma-polymerization with the monomers of fluorocarbon compounds. Both Arrhenius plots of permeability coefficients for oxygen ((?)_O_2) in the membrane samples before and after modification showed significant increase in the vicinity of the T_(KN) of EBBA.     

DETERMINATION OF PERMEATION PROPERTIES OF GAS THROUGH POLYMER MEMBRANE BY GAS CHROMATOGRAPHY

An apparatus constructed for measuring permeation properties of polymer membranes using a mixture of gases is described. A gas chromatographic system was applied to determine the individual transport characteristics of component gases without a vacuum line. This paper also discusses some experimental factors effecting the precision of measurement. The results show that there is a linear relationship between the permeation time and the volume of the gas permeated through the membrane within certain permeation period, which depends on the permeation rate (from 10~(-4) to 10~(-7) cm~3 (STP)/cm~2. sec. cmHg) of the membrane. The reproducibility has been found to be good with a relative standard deviation of 3.5%. This method is more sensitive, considerably faster and more convenient for determining both the permeability coefficient and the separation factor of a polymer membrane from a chromat ogram using mixed penetrant gases.     

芳香聚酰胺纤维的结构鉴定方法研究

用红外光谱方法分析了聚对苯甲酰胺(Ⅰ)和聚对苯二甲酰对苯二胺(Ⅱ)的谱带特征及其与结构的关系,指出了两者的区别,并用二向色性观察了薄膜的取向态,改进了化学分析方法,从(Ⅱ)的水解产物中分离和鉴定了对苯二甲酸和对苯二胺,确定了Kevlar-49纤维的结构属于(Ⅱ),还用差热分析方法比较了T_m和T_d等数据。