双功能催化剂体系作用下乙烯二聚和共聚合的研究

用乙烯为原料在双功能催化剂体系的作用下通过二聚和共聚合反应，直接合成线性低密度聚乙烯（ＬＬＤＰＥ）．所用二聚反应催化剂为钛酸正丁酯（Ｔｉ（ＯＢｕ）_４），共聚催化剂为ＴｉＣｌ_４／ＭｇＣｌ_２（ＺＭ－１催化剂）．研究了二聚反应动力学行为及影响双功能催化剂体系动力学过程的一些因素．结果表明利用这两种催化剂组成双功能催化剂体系能够很方便地制得密度范围在０．９０－０．９３，Ｅｔ／１０００Ｃ在１０－４０的ＬＬＤＰＥ．     

聚乙烯与聚乙烯-乙丙橡胶(聚乙烯-乙丙橡胶-聚乙烯)共混物X-射线衍射谱分析

近年来将因子分析这一多变量统计分析技术成功地用于具有加和性的谱分析中。因子分析法可正确定出混合物中含有的物种(因子)数和各物种的含量(浓度),同时可将各组分的纯光谱由混合物的光谱中分离开。聚乙烯(PE)和乙丙橡胶(EPR)的二、三元嵌段共聚物(PE-EPR、PE-EPR-PE)构成的共混物结构、形态与结晶过程研究已有     

聚乙烯拉伸过程中晶态变化及形变机理

用红外光谱和X-射线衍射研究了室温拉伸的聚乙烯,结果显示单斜晶存在于室温拉伸的聚乙烯中。对Hendra等关于拉伸过程机理的“微熔融”理论及其所根据实验结果提出异议,而本文的,实验结果支持了Peterlin模型。     

交联聚乙烯基吡咯烷酮的合成及其性能研究

以乙烯基吡咯烷酮（NVP）为单体，二乙烯基苯为交联剂，AIBN为引发剂，采用悬浮聚合法合成了性能稳定的交联聚乙烯基吡咯烷酮（PVPP），研究了聚合温度，引发剂用量，交联剂用量和反应气氛等因素对产率，溶胀性能和吸附性能的影响，并用红外光谱和扫描电镜等对产物的结构、性能和表面形貌进行了表征。     

IMPROVED PROPERTIES OF METALLOCENE-CATALYZED LINEAR LOW-DENSITY POLYETHYLENE/POLYPROPYLENE BLENDS DURING ULTRASONIC EXTRUSION

Metallocene-catalyzed linear low-density polyethylene/polypropylene （mLLDPE/PP） blends were prepared by ultrasonic extrusion in this work. Their extrusion processing behaviors were estimated by online measured data, such as the die pressure and flow rate. Crystallization and mechanical properties of the blends were also investigated. The results show that the addition of PP improves the processing behaviors of mLLDPE, but has little effect on its mechanical properties. On the other hand, the addition of mLLDPE improves the impact strength of PP, but has little effect on its processing behavior. The processing behaviors and mechanical properties of mLLDPE/PP blends get further improved due to the presence of ultrasonic oscillation during extrusion. Compared with PP-rich blends, the apparent viscosity drop of mLLDPE-rich blends is more sensitive to ultrasonic oscillation. The ultrasonic oscillation affects the crystal nucleation, while barely the other crystalline behaviors of the blends.     

聚酰亚胺／聚N－乙烯吡咯烷酮分子复合物的合成和表征

由原位缩聚制备了刚性高分子聚酰亚胺（ＰＩ）和柔性基体聚Ｎ－乙烯吡咯烷附（ＰＶＰ）的分子复合物，并由实验证明了中间体聚酰胺酸（ＰＡ）和聚乙烯吡咯烷酮大分子之间存在的酸一碱相互作用．这种相互作用促进了混容性，使聚酰亚胺能以分子水平或接近分子水平分散在聚毗咯烷酮的基体之中．聚酰亚胺／聚Ｎ－乙烯吡咯烷团分子复合物的薄膜呈透明性，在整个组成范围内只有一个Ｔｇ，显示单相行为。当ＰＩ含量＜２０％时，ＳＥＭ相片呈现均相形貌，看不到ＰＩ微晶．广角Ｘ－ｒａｙ衍射图表明ＰＩ特征结晶峰消失，和无定形的ＰＶＰ完全混容．当ＰＩ含量＞４０％，ＳＥＭ显示有均匀分布的、棒状ＰＩ微晶存在．通过分子复合，即使ＰＩ含量为１０％，聚Ｎ－乙烯吡咯烷酮不再溶于乙醇，耐热性也有提高．     

PREPARATION OF POLY（METHYL METHACRYLATE）/LAYERED DOUBLE HYDROXIDES NANOCOMPOSITES via in situ SOLUTION POLYMERIZATION

An exfoliated layered double hydroxides/poly(methyl methacrylate)(LDHs/PMMA)nanocomposite was prepared by in situ solution polymerization of methyl methacrylate(MMA)in the presence of 4-vinylbenzenesulfonate intercalated LDHs(MgAl-VBS LDHs).MgAl-VBS LDHs was prepared by the ion exchange method,and the structure and composition of the MgA1-VBS LDHs were determined by X-ray diffraction(XRD),infrared spectroscopy and elemental analysis.XRD and transmission electron microscopy(TEM)were employed to examine the structure of LDHs/PMMA nanocomposite.It was indicated that the LDHs layers were well exfoliated and dispersed in the PMMA matrix.The grafting of PMMA onto LDHs was confirmed by the extraction result and the weight fraction of grafted PMMA increased as the weight fraction of LDHs in the nanocomposites increased.     

SYNERGISTIC MODIFICATION OF EPDM AND CROSSLINKING AGENT IN IMMISCIBLE BLENDS OF POLYVINYL CHLORIDE WITH LOW DENSITY POLYETHYLENE

The synergism of ethylene-propylene-diene monomer copolymer （EPDM） and dicumyl peroxide （DCP, a crosslinking agent） in low density polyethylene （LDPE）/poly（vinyl chloride） （PVC） blends was investigated. When EDPM and DCP are added to the blends simultaneously, the tensile properties could be improved significantly, especially for the blends with LDPE matrix. For example, incorporation of 10/1 （mass ratio） EPDM/DCP improves the tensile strength of the LDPE/PVC （mass ratio 80/20） blend from 7.9 MPa to 8.5 MPa and the elongation at break from 25% to 503%. Results from selective extraction, phase-contrast microscopy and thermal analysis reveal that the improvement in the tensile properties of the blends with LDPE matrix is principally due to the formation of a fine crosslinking network of the LDPE and EPDM phase. The outstanding modification effect of EPDM is explained by its dual functions： molecular entanglement with LDPE and the enhanced efficiency of DCP in the blends.     

N－甲基吡咯烷酮、α－吡咯烷酮合成物系气相色谱分析

 This paper describes a GC analytical method in the synthes is of N-methyl pyrrolidone of a-pyrrolidone.This procedure was performed with a column packed with 6%OV-17/silanized 101 support and FID detec-tor. Calibration factors and detection conditions are given,The coefficients of variation of NMP and a-P were0.6%and 0.5%respectively. The relative errors of all the components were not more than±3.0%,Thequantitative analysis is fast,simple and accurate.     

官能化蒙脱土负载双金属催化芳香氯化物水相脱氯

用PVP(聚乙烯吡咯烷酮)络合双金属Pd^2 ,Sn^4 后，再负载于用PEG400(平均分子量为400的聚乙二醇)官能化的蒙脱土上，制成双金属催化剂PVP—PdCl2-SnCl4/Montk10-PEG400,用于催化难溶于水的芳香卤化物水相脱卤，芳香族氮化物转化率达100％，该催化剂可重复使用。对催化剂进行了IR及TEM表征。