AN ATOMIC FORCE MICROSCOPY STUDY ON THE AGGREGATION OF ISOTACTIC POLY（METHYL METHACRYLATE）

Aggregation process of isotactic poly(methyl methacrylate) (i-PMMA) has been studied extensively for many years, and considerable progress has been made in both experimental and theoretical studies. They are, however, seldom sustained by real-space observations of the underlying morphology. In this paper, the aggregation process of i-PMMA in concentrated acetone solutions and the fractal structure of the resulting three-dimensional clusters were characterized on the basis of real-space AFM observations of their two-dimensional projection. It was found that spherical multiple-chain particles formed upon collapse and aggregation of the involving chains as a whole during quenching the solution to room temperature. By keeping the solution at room temperature, the initially formed particles stick together upon contact to form larger particles through reassembling very slowly. The succeeding collision of the enlarged spherical particles leads to the formation of small clusters. These newly formed small clusters grow when they meet with other clusters or single Brownian particles. This leads to the formation of large clusters with fractal dimension of 1.95$±0.05, which suggest a reaction-limited cluster aggregation of i-PMMA in a concentrated acetone solution. This is in accordance with the conclusion obtained by light scattering measurements.     

聚合物驱蚊剂的慢释放研究

本文研究了丙烯酸酯共聚物载体对驱蚊剂N,N-二乙基间甲苯酰胺(DETA)慢释放行为的控制,探讨了单体配比、共聚物分子量以及DETA含量对释放速率的影响。结果表明。增加亲水性单体丙烯酸(AA),可提高DETA的释放速率;降低共聚物数均分子量,会减少DETA的释放量;剂型中DETA含量与释放量存在线性正比关系,但DETA的含量增加并不导致释放有效时间的线性增加。本文还就共聚物膜的透湿性和碱溶性作了研究,亲水性单体AA的增加同样导致透湿性和碱溶性的增加。制备的聚合物驱蚊剂经现场应用试验,表明具有良好的长效驱蚊特性。     

热致液晶共聚酯对聚丙烯结晶的诱导作用

用差示扫描量热法和光学解偏振法研究了热致液晶性芳香共聚酯与聚丙烯共混物的等温和非多温结晶行为.结果表明,这一热致液晶聚合物对聚丙烯结晶有诱导成核和加速作用.当共聚酯含量在2-5％之间时,聚丙烯的结晶速率最快.偏光显微镜的观察揭示出在聚丙烯熔体中原位形成的液晶聚合物微纤诱导了聚丙烯横穿晶的形成.     

双-单齿芳香酰胺型配体桥联La3＋一维配位聚合物的合成与晶体结构

通过硝酸镧和双-单齿芳香酰胺型配体L {L＝1,4-双[(2'-苄胺甲酰基苯氧基)-甲基]苯}之间的反应得到了配位聚合物{[La(NO₃)₃]₂•L₃}_n, 并用X射线单晶衍射测定了配合物的晶体结构. 配合物为三斜晶系, _P1空间群, 晶胞参数a＝1.1298(2) nm, b＝1.2689(1) nm, c＝2.1030(3) nm, α＝81.189(9)°, β＝80.95(1)°, γ＝65.832(9)°, V＝2.7032(6) nm³, Z＝2, R＝0.0267, wR＝0.0679, La^3＋为9配位, 呈变形的三帽三角棱柱配位构型. 配合物通过配体的桥联作用形成一维环链相间的配位聚合结构, 由于相邻链间不存在氢键和π-π堆积作用, 所以配合物是以单链形式堆积排列.     

配位聚合物{[Co2(HBTC)2(H2O)6]·C4H10N2·2H2O}n的水热合成、结构表征及荧光性质

采用水热法合成了配位聚合物[Co2(HBTC)2(H2O)6]·C4H10N2·2H2O}n(H3BTC为1,3,5-均苯三羧酸,C4H10N2为哌嗪),通过X射线单晶衍射、红外光谱和荧光光谱进行表征,并用TGA研究了该配位聚合物的热稳定性.晶体属三斜晶系,P1空间群,a=1.05437(9)nm,b=1.05485(9)nm,c=0.71482(5)nm,α=102.4623(28)°,β=91.3500(42)°,γ=111.0186(29)°,V=0.72018(10)nm3,Mr=764.37,Dc=1.762g·cm-3,Z=1,μ(MoKα)=1.25mm-1,F(000)=394,R=0.0307,wR=0.0815.晶体的基本构建单元中包含2个Co()中心、2个配位的HBTC分子和6个配位的水分子.基本构建单元通过相互链接形成具有“Z”型结构的一维配位聚合链,链间通过两种不同的氢键(O—H…O和N—H…O)相互作用,进而形成具有三维骨架结构的微孔晶体,微孔大小为0.71nm×0.82nm.荧光光谱表明,常温下用λex=312nm的光激发后,配位聚合物在329nm处出现强烈的荧光发射.     

Synthesis of Lanthanide Coordination Polymers with Benzophenone-4,4′-dicarboxylate： Effect of Lanthanide Contraction on Structures

Four lanthanide coordination polymers with benzophenone‐4,4′‐dicarboxylic acid (H₂bpndc) and 1,10‐phenanthroline (phen), [Ln₂(bpndc)₃(phen)] (Ln=La (1), Pr (2) and Tb (3)), [Yb(bpndc)₁₅(phen)].05H₂O (4) were obtained through solvothermal synthesis. The crystallographic data show that 1, 2, and 3 are isostructural, the Ln(III) ions in 1, 2 and 3 are all eight‐ and ten‐coordinated, respectively, and thus the Ln(III) ions are connected by bpndc ligands, resulting in an interpenetrating 3D structure. While in 4, the Yb(III) ions are eight‐coordinated and connected by bpndc ligands into a 3D structure with 1D rhombic channels, which result from the effect of lanthanide contraction from La(III) to Yb(III) ions, and the bpndc ligands in 1, 2, 3, and 4 display three types of coordination modes.     

高固含量聚合物乳液制备方法新进展

高固含量一直是聚合物乳液制备追求的目标 ,本文将高固含量 (>6 0 % )聚合物乳液的制备方法按机理分为控制乳胶粒直径分布 ,增大乳胶粒直径和使乳胶粒发生形变三类 ,详细评述了各种制备方法的研究进展 ,并对高固含量乳液制备的发展进行了展望。     

聚合物共混物脆韧转变性能研究 Ⅱ准韧性聚合物共混物脆韧转变的几何模型

给出了分散相粒间基体层厚度Ｔ与分散相粒径（ｄ）、粒径分散度（σ）和分散相体积分数（）的定量关系式．发现σ对Ｔ的影响与有关，不仅Ｔ随σ的增大而增大，而且越大，这种影响越显著．用计算机图像分析仪直接测定了聚氯乙烯／丁腈橡胶、聚丙烯（ＰＰ）／三元乙丙橡胶、ＰＰ／乙烯 醋酸乙烯酯共聚物共混物的Ｔ，发现这三种共混物的Ｔ近似于对数正态分布．理论预示与实验结果很好符合．     

β-蒎烯和马来酸酐的反应及产物表征

研究了β-蒎烯和马来酸酐的烯反应、溶剂中自由基共聚反应和本体热共聚反应,得到了β-蒎烯和马来酸酐烯反应产物和共聚产物,并用IR、1H NMR、13C NMR、GPC、DSC进行表征,研究了引发剂浓度、溶剂体系、单体配比、温度等因素对产物的影响.对聚合物进行皂化改性,测量了皂化物浓度对水表面张力的影响.     

超支化聚硅(碳/氧)烷的研究进展

总结了近十年来超支化聚有机硅(碳/氧)烷的研究进展,其中着重综述了硅氢加成反应、亲核取代反应和脱氢反应在制备超支化聚硅(碳/氧)烷的过程中各种因素对反应过程及产物物化性能的影响。