低头-头链含量的聚偏氟乙烯合成

研究了偏氟乙烯的聚合条件与其聚合物的头-头链含量的关系。实验表明聚合物的头-头链的含量与聚合温度有关,而与引发剂的种类无关。因而,可以在较低的聚合温度下聚合制得带有低的头-头结构(约3％)的聚偏氟乙烯。将聚合物链的A结构含量对其熔点作图,得一直线,可表示为方程式A=24.8+0.362T_m(％)。     

葡萄糖对聚偏氟乙烯膜的共混改性研究

以葡萄糖为共混剂,聚乙烯吡咯烷酮为添加剂,用相转化法获得了聚偏氟乙烯/葡萄糖共混膜。研究了聚偏氟乙烯浓度,葡萄糖与偏氟乙烯的共混比例和添加剂含量等各项制膜条件对微孔膜的结构和性能的影响。结果显示当聚偏氟乙烯的固含量为10wt%,葡萄糖含量为4wt%,聚乙烯吡咯烷酮为固含量的2wt%,溶液蒸发时间为30min时,能够得到性能理想的微孔膜。     

聚偏氟乙烯溶液法接枝苯乙烯磺酸膜的结构与形貌研究

以过氧化苯甲酰(BPO)作引发剂，通过溶液接枝聚合法把苯乙烯接枝到碱处理过的聚偏氟乙烯(PVDF)膜上，磺化后得到聚偏氟乙烯接枝苯乙烯磺酸(PVDF-g-PSSA)电解质膜。研究发现碱处理过的PVDF膜更容易与苯乙烯发生接枝聚合反应，且接枝率与碱处理时间呈线性变化关系。用红外光谱、差示扫描量热法检测PVDF膜经过接枝以及随后的磺化所发生的膜结构变化，并用SEM观察PVDF膜接枝前后以及接枝磺化后产物PVDF-g-PSSA膜的形貌及硫分布。研究表明，用KOH碱处理过的PVDF膜与苯乙烯进行接枝共聚反应时，PVDF膜结构在接枝前后和磺化前后发生变化，说明苯乙烯确实接枝到PVDF膜上。     

聚偏氟乙烯的辐射交联及其交联度的XPS表征

本文首次用XPS研究了聚偏氟乙烯的辐射交联机理,交联度的XPS表征。计算出聚偏氟乙烯的β值为0.7,发现聚偏氟乙烯的辐射交联的溶胶分数与辐照剂量的关系符合我们提出的通式^[1]。用XPS方法求得聚偏氟乙烯的凝胶化剂量为1.59mrad。     

聚偏氟乙烯/蒙脱土纳米复合材料的形态结构

采用有机改性的蒙脱土与聚偏氟乙烯熔融共混, 制备了聚偏氟乙烯/蒙脱土纳米复合材料. 利用X射线衍射分析、透射电子显微镜(TEM)和Molau实验研究了复合材料的微观结构. 通过X射线衍射、傅里叶变换红外光谱(FTIR)以及差热扫描(DSC)研究了有机改性蒙脱土对聚偏氟乙烯结晶结构的影响. 结果表明, 有机改性蒙脱土在聚偏氟乙烯中以插层、剥离和碎片的形式存在. 在X射线衍射谱中发现蒙脱土的(001)峰向低角方向移动, 在TEM中可见到剥离的片层碎 片.蒙脱土的引入改变了聚偏氟乙烯的结晶结构, 导致了具有压电性能的β相形成, 引起α相内应力的产生, 同时也导致了聚偏氟乙烯基体的结晶度下降, 球晶尺寸随蒙脱土含量明显减少. 蒙脱土引起的β相在 160℃退火表明是相当稳定的. 根据这些实验结果, 对由于蒙脱土的引入引起的聚偏氟乙烯结晶结构的变化提出了可能的解释.     

铁电高分子聚偏氟乙烯-三氟乙烯的凝聚态结构与性能调控研究进展

高分子的凝聚态结构具有多层次性,在微纳米尺度上有效地控制高分子的凝聚态结构,进而探索在微纳米尺度上凝聚态结构与性能的关系,将为高分子分子层次和宏观层次的结构与性能之间架起桥梁。本文综述了近年来我们课题组在铁电高分子聚偏氟乙烯-三氟乙烯共聚物方面的研究及其进展。发展了在纳米尺度上控制高分子片晶取向的新方法并应用到聚偏氟乙烯-三氟乙烯体系,构筑了取向高度有序的铁电高分子纳米结构阵列,分析了片晶取向与聚偏氟乙烯-三氟乙烯微观铁电和压电性能之间的关系,有效降低了以聚偏氟乙烯-三氟乙烯为主要材料的有机铁电非易失性存储器的读写电压。     

聚偏氟乙烯薄膜压电性的研究

本文研究了聚偏氟乙烯的压电性。聚偏氟乙烯薄膜是用DMA溶剂浇铸而成,然后进行单轴拉伸,并采用热驻极的方法使薄膜成极。实验结果表明,压电活性依赖于拉伸比、极化电场、极化温度和极化时间。此外,还研究了聚偏氟乙烯压电薄膜的稳定性和某些使用特性。     

用重氮盐引发N-乙烯咔唑之光聚合研究

<正> 聚N-乙烯咔唑[P(N-VCz)]是典型的有机光导体,已被广泛应用于静电照相和光导热塑全息记录中。 N-乙烯咔唑是一种聚合活性较大的单体,聚合反应可通过自由基、阳离子、Zeigler-Natta型催化剂和电荷转移引发等途径进行。 已有报道,芳香族重氮盐可作为光聚合引发剂。如对环氧化合物、丙烯腈等单体的聚     

药物氟哌酸分子印迹聚合物膜的制备及其渗透性质研究

以聚偏氟乙烯微孔滤膜为支撑膜,氟哌酸为模板分子,用紫外光引发原位聚合方法制备了分子印迹聚合物膜.研究了模板分子与功能单体之间的相互作用,用扫描电镜表征了膜的表面形貌.混合底物渗透实验结果表明,分子印迹聚合物膜中存在着由形状和功能基团均与模板分子氟哌酸相互补的孔穴组成的通道,该通道可选择性地富集底物分子.     

含氟烯类的自由基型加成反应

一、序言含氟塑料和橡胶如:聚四氟乙烯,聚三氟氯乙烯,聚一氟乙烯,聚偏二氟乙烯,以及含氟弹性体等,都是由相应含氟烯烃通过自由基引发的聚合或共聚得到的。利用自由基型的调聚反应,则可合成“氟油”及“调聚酸”等产品。聚合、共聚或调聚的共同基本过程是自由基型的加成反应。因此含氟烯类的自由基加成反应不仅有着广泛地实用价值,并且在理论方面也有其重要意义。特别是加成中的定位方向问题,引起了人们的极大兴趣。1954年Cadogan和Hcy曾总结过烯类体系的自由基型加成反应。近年来,这方面的工作又有了补充和发展。本文即依据近年来有关含氟烯类的研究工作和成就,概括的作一综述性报导。并侧重讨论定位问题。     

啶虫脒分子烙印聚合物的识别特性

利用分子烙印技术,以啶虫眯为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,合成了对啶虫脒具有高度选择性的模板聚合物,通过平衡吸附实验,评价了其对啶虫眯的亲和力和选择性.与空白烙印聚合物相比,对啶虫脒表现了很高的亲和力.Scatchard分析表明,在啶虫脒模板聚合物中存在对啶虫脒有不同亲和力的两类作用位点,高亲和力的吸附位点的离解常数为Kd1=4.68×10-4mol/L,最大表观吸附量QMAX1=18.8μmol/g,低亲和力位点的离解常数为Kd2=7.93×10-3mol/L,最大表观吸附量QMAX2=142μmol/g.通过与啶虫脒类似物质在啶虫脒模板聚合物上的吸附行为比较,表明对啶虫脒具有很好的选择性.     

后重氮偶合法制备咔唑类光折变聚合物

生色团;后重氮偶合法制备咔唑类光折变聚合物     

Copolymerizable initiator for improved polymer dispersed liquid crystal films

The problems of photoinitiator contamination are addressed for the liquid crystal phase in polymer dispersed liquid crystal films formed by photopolymerization induced phase separation of liquid crystal from monomer solutions. Initiator contamination lowers the clearing point of the liquid crystal phase, and decreases the photostability and resistivity of the polymer dispersed liquid crystal. These problems are minimized by replacing the conventional photoinitiators with copolymerizable initiators which become incorporated in the polymer phase as it separates. Copolymerizable photoinitiators are studied and used to form polymer dispersed liquid crystals with higher clearing point liquid crystal phases, higher resistivity, and better photostability than polymer dispersed liquid crystals formed with conventional photoinitiators. These improvements provide very significant advantages for many polymer dispersed liquid crystal applications.     

Copolymerizable initiator for improved polymer dispersed liquid crystal films

Abstract

The problems of photoinitiator contamination are addressed for the liquid crystal phase in polymer dispersed liquid crystal films formed by photopolymerization induced phase separation of liquid crystal from monomer solutions. Initiator contamination lowers the clearing point of the liquid crystal phase, and decreases the photostability and resistivity of the polymer dispersed liquid crystal. These problems are minimized by replacing the conventional photoinitiators with copolymerizable initiators which become incorporated in the polymer phase as it separates. Copolymerizable photoinitiators are studied and used to form polymer dispersed liquid crystals with higher clearing point liquid crystal phases, higher resistivity, and better photostability than polymer dispersed liquid crystals formed with conventional photoinitiators. These improvements provide very significant advantages for many polymer dispersed liquid crystal applications.     

On the origin of mesoscopic inhomogeneity of conducting polymers

The mesoscopic inhomogeneity of conducting polymer films obtained by electropolymerization and spin-coating was studied using Kelvin probe force microscopy (KFM) and current-sensing atomic-force microscopy (CS-AFM). A well-pronounced correlation was established between the polymer morphology, on the one hand, and its local work function (which is related to the polymer oxidation degree) as well as polymer conductivity, on the other. The most conducting regions were associated with the tops of the polymer grains and showed Ohmic behavior. They were surrounded first by semiconducting and then by insulating polymer. The conductivity of the grain periphery could be lower by as much as 2 orders of magnitude. The grain cores also showed consistently higher values of the local work function as compared to the grain periphery. This fact suggested that the grain cores were more oxidized and/or more ordered as compared to the grain periphery, which is in good agreement with the local conductivity data. More uniform morphology corresponded to less variability in the other properties of the polymer. A model is proposed that relates the observed inhomogeneity to preferential deposition of polymer molecules with higher molecular weight at the early stages of the polymer phase formation. The polymer deposition in either electropolymerization or various solution-casting techniques involves the nucleation of a new phase from a solution containing polymer fractions of different molecular weights. The driving force of the nucleation process depends on the solubility of the polymer fractions, which decreases with an increase in the molecular weight. This gives rise to preferential deposition of more crystalline, higher molecular weight polymer at the early stages of the polymer deposition to form the cores of the polymer grains. The fractions with lower molecular weights are deposited later and form less ordered/less conducting grain periphery. On the basis of this model, we conclude that, to ensure the formation of materials with low inhomogeneity and high quality, one should use the starting polymer with as narrow molecular weight distribution as possible. Yet another possibility is to use solvents which would reduce the differences in the solubilities of polymer fractions with different molecular weight.     

药物甲氧苄氨嘧啶分子模板聚合物膜的选择性结合及透 过性质研究

用分子印迹技术制备了对甲氧苄氨嘧啶具有特异结合和透过性质的膜状分子模板聚合物,Scatchard分析表明,在分子模板聚合物膜中存在一类等价的可与甲氧苄氨嘧啶结合的位点,该结合位点的平衡离解常数为Kd=4.85×10^-2mmol/L,甲氧苄氨嘧啶分子模板聚合物膜的选择性透过实验表明,在该聚合物膜中存在着由形状和功能基团均与模板分子甲氧苄氨嘧啶相互补的孔穴组成的通道,该通道可有选择性地通过模板分子。     

一种新型的交联极化聚合物的合成及性能研究

以成膜性能优异、主链上含有多个羟基的聚双酚A二缩水甘油醚-苯胺(BPAN)为骨架,将二阶非线性光学活性发色团分子以键合形式挂接到聚合物主链上,形成新型侧链型聚合物.此聚合物保留了原聚合物体系成膜性好和可进一步交联等优点.极化过程中以含有异氰酸酯基的同种发色团分子作为交联剂,得到发色团含量进一步提高的交联型极化聚合物.采用衰减全反射法(ATR)测得体系的电光系数(r₃₃)为6.7 pm/V(1315 nm).     

The structure and properties of polymer-metallic coating interphase

The structure of the surface layer in polymers (LDPE and PET) decorated with a thin metal (gold and platinum) layer was studied after their deformation under different conditions. It was found that relatively thick coatings debonded from the polymer substrate during tensile drawing. Debonding was observed at low tensile strains (below 20–30%). During the further drawing of a polymer, a regular microrelief typical of deformable “rigid coating on a soft substrate” systems appeared on its surface. This phenomenon is explained by the fact that the debonding metal coating uncovers not the surface of the pure polymer but a certain modified layer, which has a higher elastic modulus than the pure polymer. The formation of this layer is associated with the inclusion of metal atoms into the polymer during the metal decoration by plasma immersion ion deposition. As a result of this inclusion, a modified layer, which has a higher glass transition temperature, a higher elastic modulus, and other mechanical properties, is formed between the coating and the polymer.     

β-二酮钛非茂催化剂催化降冰片烯聚合

用 (dibenzoylmethanato) 2 Ti(OPh) 2 [(dbm) 2 Ti(OPh) 2 ]/甲基铝氧烷 (MAO)为代表的新型 β 二酮钛非茂催化剂实现了降冰片烯的聚合 ,得到加成聚合和开环易位聚合的混合物 ,研究了实现高聚合活性所需的特殊条件及所得的聚合物结构 ,主要应用傅立叶转变红外技术 (FTIR)对聚合物结构进行了表征和分析     

Properties of composite solid polymer electrolyte using hyperbranched polymer with ether-linkage

The cross-linked composite solid polymer electrolytes composed of poly(ethylene oxide), lithium salt (LiN(SO₂CF₃)₂), and a hyperbranched polymer whose repeating units were connected by ether-linkage (hyperbranched polymer (HBP)-2) were prepared, and their ionic conductivity, thermal properties, electrochemical stability, mechanical property, and chemical stability were investigated in comparison with the non-cross-linked or cross-linked composite solid polymer electrolytes using hyperbranched polymers whose repeating units were connected by ester-linkage (HBP-1a, 1b). The cross-linked composite solid polymer electrolyte using HBP-2 exhibited higher ionic conductivity than the non-cross-linked and cross-linked composite solid polymer electrolytes using HBP-1a and HBP-1b, respectively. The structure of the hyperbranched polymer did not have a significant effect on the thermal properties and electrochemical stability of the composite solid polymer electrolytes. The tensile strength of the cross-linked composite solid polymer electrolyte using HBP-2 was lower than that of the cross-linked composite solid polymer electrolyte using HBP-1b, but higher than that of the non-cross-linked composite solid polymer electrolyte using HBP-1a. The HBP-2 with ether-linkage showed higher chemical stability against alkaline hydrolysis compared with HBP-1a with ester-linkage.