溴代及胺交联聚苯醚（PPO）膜的气体透过行为

对聚苯醚(PPO)进行了苯环溴代、甲基溴代以及胺交联,发现苯环溴代可提高O_2、N_2透过率(P),而选择性(α)基本不变。甲基溴代则相反,P降低、α有明显提高。调节两者比例可得到P、α兼优的O_2、N_2分离膜。甲基溴代后进一步胺交联可得到α更高、耐溶剂的膜材料。     

GAS SORPTION AND TRANSPORT IN POLY (PHENYLENE OXIDE)(PPO)AND ARYL-BROMINATED PPO MEMBRANES

The apparent solubility (S), concentration-average diffusivity (D), and permeability (P), for C0_2, CH_4 and N_2 through PPO and aryl-brominated PPO at 35℃for pressure ranging from 1 to 26 atm are reported. It is found that P, D, and S of the membranes to all the three gases vary with the extent of bromination. S increases with the increase of the percent of bromine in each case, but D to CO_2 increases remarkably only at higher degree of brominafion, and therefore, P to CO_2 is increased by more than 100% over a wide range ofpressure in the case. The solubility data are well described by the dual mode sorption model. It is found that the gas molecules sorbed by the Langmuir mode are relatively more immobilized and the contribution of the nonequilibrinm character of the polymer to gas permeation increases obviously for CO_2 and is hardly changed for CH_4 with increasing bromine content. These observations are interpreted in terms of changes in specific free volume (SFV)and the cohesive energy density (CED) of the polymers.     

热处理过程中非晶态聚芳酯超分子结构的变化

本文采用TEM、SAXS及DSC等方法研究了经WAXD证明的芳香族聚酯在T_g,附近退火过程中形成的区域结构,在TEM观察中采用了金装饰制样技术,使形态观察更为清晰,在SAXS测量中采用了Kratky准直系统而提高了分辨率,在DSC测量中,从剩余焓(△H)对升温速率作图,求得热力学平衡态时的(△H)_0。结果证明,聚芳酯在T_g以下长时间退火时,可以形成40—60nm的区域结构。     

有较高抗撕裂强度的稀土顺丁充油橡胶的研究

本工作采用电子显微镜(EM)、大角度X射线衍射(WAXD)、热失重分析(TGA)、动态力学测定等方法,研究了几种典型油品的充油Ln-BR的形态结构和结晶动力学,发现减压渣油(9号油)分子量较高,与Ln-BR的相容性较差,且与硫化后的Ln-BR间可能有少量的化学联结。它的存在明显地促进了Ln-BR的应力诱导结晶(SIC)。这些因素均导致这种充油硫化胶有较高的抗撕裂强度。     

HEAT SHRINKING BEHAVIOUR OF γ-RADIATION CROSSLINKED POLYETHYLENE

Heat shrinking material of γ-radiation erosslinked polyethylene is widely used for various application in industry. In this study, DSC, TMA, WAXD and density measurement techniques were used to investigate the influence of MI and thermal history of LDPE on the effectiveness of network formation. Based on the results of heat stretching and heat shrinkage tests, it is found that the formation of a network as perfect as possible is indispensable to the irradiated material if good heat shrinkage property is desired. To this end, quenching technique and polyethylene with appropriate MI must be used so that an effective radiation effect will be obtained with a minimum amount of radiation dose. In spite of that the mechanical property of the irradiated polyethylene in the rubbery state is basically in agreement with the classical expression of the theory of high elasticity, only about 90% shrinkage can be reached. Besides, the heat shrinkage temperature T_s and the % shrinkage Sare both related to the radiation dose.     

AN EXTENSION OF THE METHOD FOR PREDICTING PERMEABILITY THROUGH POLYMER MEMBRANES FROM SIMPLE GASES TO WATER VAPOR

It is found that there is a linear relationship between log P_w and the parameter termV_f/0. 5 E_(coh)[1+(δ_w-δ_p)~2/δ_p~2], from the water permeability (P_w) data of 21 polymerscovering 4 orders of magnitude. This correlation may be useful in choosing membranematerials for dehumidification of gases.     

聚苯醚的溴化及其对富氧性能的影响

利用亲电反应及自由基反应分别对聚苯醚进行了不同程度的溴化。测定了不同温度下对O_2和N_2的透过率及相应的玻璃化转变温度和密度。发现苯环上的溴化有利于提高O_2和N_2的透过率,而选择性基本不变。甲基上的溴化大大提高了O_2、N_2的选择性,但透过率下降较多。苯环上溴含量与Tg呈很好的线性关系,密度亦随溴含量的增加而增加。透过率与温度的关系符合Arrhenius方程。溴化后的聚苯醚其透过活化能略有下降,并计算了溴化聚苯醚的摩尔自由体积和摩尔内聚能,发现其比值越大,O_2、N_2的透过率越大。     

由聚合物结构预测气体的透过性能

本文利用基团加和法,对20多种常见聚合物的自由体积和内聚能进行了计算。发现氧气和氮气在聚合物膜中的透过率与自由体积和内聚能的比值有直接关系。此比值越大,气体的透过率越大,透过率的对数与自由体积和内聚能的比值基本呈线性关系。据此,对未知聚合物可根据其化学结构,从已有的基团数据计算该比值,从而预测它对氧气和氮气的透过性能。     

高分子除湿膜的进展

高分子除湿膜是新近出现的一种气体分离膜。本文就水分子在高聚物中的透过特点和高分子除湿膜的选材进行了扼要的综述。最后介绍了国外几种已商品化的除湿组件的性能和应用。     

顺丁橡胶的聚集态结构及其拉伸行为

用电子显微镜及光学显微镜研究了高顺式1,4-聚丁二烯橡胶的聚集态结构及其对力学性能的影响。观察了样品的低温结晶、室温下的溶胶和凝胶结构,及其拉伸和松弛过程。证明在室温下,无定形结构的顺丁橡胶内部并不是均匀的,而是具有一定规整度的区域所组成。其基本单元为链结(nodule),链球(Aggre-gation of nodules),及胶团(cluster of gel)。结构单元及其连接均与分子量及凝胶含量有关。这些结构因素均通过超分子结构而影响拉伸及松弛行为。