可溶性聚[3-(2,2,3,3-四氟丙氧基)噻吩]的光谱性质

研究了中性和经FeCI3掺杂后聚[3-(2, 2, 3, 3-四氟丙氧基)噻吩](P3FT)溶液的光谱性质。中性P3FT具有特殊的溶剂色效应, 其甲醇 溶液的溶剂化吸收带强度随P3FT浓度增大而增强, 该吸收带是高分子链与链之间的相互作用(即聚合物的聚集态结构)的反映。用电子光谱跟踪FeCI3掺杂P3FT的过程, 结果表明, P3DT随着掺杂程度的增大, 载流子由极化子转变成双极化子, 且双极化子的能级位于禁带中间, 与孤子相似。     

β-PHASE CRYSTALLIZATION OF ISOTACTIC POLYPROPYLENE

Effects of cooling rate and crystallization and melt temperatures on the melting curves of predomi-nately β-phase isotactic polypropylene (IPP) were investigated by using DSC instrument. Experimental re-sults indicate that the magnitude of βmelting endctherm increases with decreasing cooling rate and withincreasing crystallization temperature. The temperature of melt has no effect on the β-phase crystallizationof IPP below 300℃, but a further increase of the melt temperature will destroy the β-phase nuclei,then the β-phase crystals will not be produced upon cooling. The linear growth rates of α- and β-phasespherulites were determined as a function of temperature between 123 and 140℃. It was found that thegrowth rate of βspherulites is higher than that of αspherulites below 140℃. Studies of the kinetics ofβ-phase crystallization of IPP were also made using a DSC instrument. The results obtained do not fitthe usual Avrami equation. But it can be described by kinetic theory of imcomplete spher     

脱氟化氢聚偏氟乙烯膜的制备, 表征和导电性能的研究

聚偏氟乙烯(PVDF)膜与一些有机弱碱作用脱氟化氢(HF)生成表面为一氟乙炔(PFA)的膜。红外、紫外可见光谱分析表明脱HF的PVDF膜的共轭链结构比较规整。X光电子能谱、反应深度和接触度的分析表明, PVDF脱HF反应主要发生在膜表面。脱HF的PVDF膜(PFA)经各种掺杂剂掺杂后电导率上升5~6个数量级, 最高可达10^-^4s/cm, 且在掺杂过程中出现出的性质不同于聚乙炔。     

残炭颗粒的形态、结构及其在燃烧过程中的分布

本文利用光学显微镜和电镜,阐述了不同残炭颗粒的形态和结构以及它们在燃烧过程中的分布特征。这些结果表明,残炭颗粒的形态结构特征不仅依赖于煤的显微组分组成,而且也依赖于煤的变质程度。由镜质组形成的残炭(包括薄壁煤胞、厚壁煤胞和网状炭)在燃烧过程中迅速减少。而来自于惰性组的未熔炭,当它以等密度方式燃烧时,其数量上的减少非常缓慢,所以它们可能导致电厂飞灰中未燃炭含量增高。     

ELECTRONIC EFFECTS OF POLYFLUORINATED SUBSTITUENTS ON THE POLYMERIZATION AND THE PROPERTIES OF POLYTHIOPHENES

Three series of polythiophenes containing fluoroalkoxy and fluoroether substituentswere prepared by electrochemical polymerization. The effect of substituents with fluoro-alkoxy or ether functional groups on the electrochemical polymerization of thiophene mono-mers and properties of the obtained polymers were analyzed. The introduction of a flu-oroether functional group at the 3-position of the thiophene ring leads to an increase ofthe oxidation potential of the monomer and to a decrease of the conductivity of the re-sulting polymers, even with the use of a CH_2 group as spacer. Conversely, the presenceof an oxygen atom directly at the 3-position of the thiophene ring, which offsets the nega-tive withdrawing effect of fluoroalkyl groups, facilitates the synthesis of highly conductingpolythiophenes.     

聚丙烯β相结晶的研究

本文研究了冷却速率、结晶温度和熔体温度等因素对聚丙烯β相结晶得到的试样的熔融行为的影响。发现β晶型熔融峰的面积随冷却速率的降低或结晶温度的升高而增加。在低于300℃的温度下,熔体温度对聚丙烯的β相结晶无影响。300℃以上的高温破坏了聚丙烯β相结晶的晶核,冷却结晶时不再生成β相晶体。测定了α相及β相球晶在123—140℃的温度范围内线性增长速率,发现在140℃以下,β球晶的增长速率大于α球晶。研究了β相结晶动力学,发现聚丙烯β相结晶不符合Avrami方程,而要用不完全球晶结晶的动力学理论来描述。     

STRUCTURAL ANALYSIS AND ENVIRONMENTAL STABILITY OF POLYFLUORINATED GROUP SUBSTITUTED POLYTHIOPHENES

Electrochemical polymerization of 3-fluoroalkoxy and 3-fluoroether thiophenes givespolymers with relatively high molecular weights and good processibility. Investigationof these polymers by means of GPC indicates that an increase in the number of fluorineatoms in the fluorinated group results in a decrease in degree of polymerization of thepolymers in the same polythiophene series. As shown by NMR and FTIR, the polyfluo-rinated group substituted polythiophenes have regular 2, 5-coupling in their main chains.The SEM micrographs of the polymer films exhibit that polymer (1)-poly [3-2, 2, 3, 3-tetrafluoro-propoxy) thiophene] possesses more regular structure than the other polymersdo. Substitution of polythiophenes by fluorinated groups leads to the polymers with highelectric, electrochemical and thermal stability.     

β晶型聚丙烯的力学性质

研究了主要含β晶型的聚丙烯在不同温度下的应力-应变性质,并与同一商品牌号得到的α晶型聚丙烯作了对比。发现,β晶型试样的屈服强度低于α晶型,而抗冲击强度则比α晶型试样高1—2倍。结合X射线衍射法对β晶型试样在拉伸过程中发生的晶型转变的研究及形变的分子机制解释了二种晶型试样在力学性质上的差异。     

可溶性聚[3-(2,2,3,3-四氟丙氧基)噻吩]的光谱性质

研究了中性和经FeCl_3掺杂后聚[3-(2,2,3,3-四氟丙氧基)噻吩](P3FT)溶液的光谱性质.中性P3FT具有特殊的溶剂色效应,其甲醇溶液的溶剂化吸收带强度随P3FT浓度增大而增强,该吸收带是高分子链与链之间的相互作用(即聚合物的聚集态结构)的反映.用电子光谱跟踪FeCl_3掺杂P3FT的过程,结果表明,P3FT随着掺杂程度的增大,载流子由极化子转变成双极化子,且双极化子的能级位于禁带中间,与孤子相似.