（4—N,N—二甲氨基）—苯基—N—苯基硝酮在高聚物薄膜中光化学反…

本工作测定了（４－Ｎ，Ｎ－二甲氨基）－苯基－Ｎ－苯基硝酮（ＤＭＡＰＮ）在不同介质中光照后折射率的变化，发现其折射率随光照时间的增长而明显降低。工作研究了ＤＭＡＰＮ在高分子薄膜内的光化学反应与高聚物分子量的关系，在分子量较低的区域，高分子介质对小分子反应的影响是不规则的，而在高分子量区，则随着分子量的增大，反应速率下降，对所得的结果进行了初步讨论。     

钠取代N－烷基化反应合成4－（N，N－二烯丙基氨基）吡啶

钠取代Ｎ－烷基化反应合成４－（Ｎ，Ｎ－二烯丙基氨基）吡啶黄积涛，孙经武，刘振华（天津理工学院化工系，天津３００１９１）（天津大学应化系，天津３０００７２）４－（Ｎ，Ｎ－二烯丙基氨基）吡啶（ＤＡＡＰ）是合成迄今已知最高活性的烷氨基吡啶高分子催化剂的单体...     

p－（N，N－二甲氨基）肉桂酸乙酯在分子聚集体中的光化学行为

本文报道了ｐ－（Ｎ，Ｎ－二甲氨基）肉桂酸乙酯（ＤＭＡＣ）在十二酸（ＬＡ）聚集体中的光谱和光化学性质．这种肉桂酸衍生物的吸收和发射光谱表现出典型的分子内电荷转移的特征，在十二酸存在下，观察到ＤＭＡＣ激基缔合物荧光，荧光强度随ＤＭＡＣ浓度增加而增加，与普通溶液中的反应相比，十二酸聚集体中的ＤＭＡＣ具有较大的光二聚反应速度．用荧光光谱跟踪反应的结果表明，ＤＭＡＣ激基缔合物具有较ＤＭＡＣ单体更高的光化学活性。     

Iniferter BDC的合成及引发St、MMA光聚合

合成Ｎ,Ｎ’－二乙基二硫代氨基甲酸苄酯（ＢＤＣ０。以ＢＤＣ作为ｉｎｉｆｅｒｔｅｒ引发Ｓｔ、ＭＭＡ光聚合,单体Ｓｔ和ＭＭＡ的转化率随光照时间的增加而增加,但没有呈现出线性关系。此外,反应环境温度高,单体转化率增加;ＰＳ和ＰＭＭＡ的粘均分子量则随光照时间的增加而呈现线性增加的关系;所得聚合物的分子量分布较宽;ｉｎｉｔｅｒｔｅｒ ＢＤＣ可以进行分子设计,合成Ｐ（Ｓｔ－ｂ－ＭＭＡ）嵌段共聚物,表现为“准活     

二安替比林－（2－甲氧基）苯基甲烷光度法测定钒

本文合成了二安替化林－（２－甲氧基）－苯基甲烷（ＤＡＯＭＭ）并用元素分析、红外分析对其进行了鉴定。在吐温２０和Ｍｎ（Ⅱ）存在下，ＤＡＯＭＭ与钒（Ｖ）反应，生成橙黄色产物，λｍａｘ＝４８０ｎｍ，摩尔吸收系数ε＝３．１×１０５Ｌ．ｃｍ－１、ｍｏｌ－１。０．５～４μｇＶ（ｖ）／２５ｍｌ符合比尔定律。用于中草药中痕量钒的侧定，结果满意。     

反－α－苯基邻硝基肉桂酸合成工艺探讨

本文详细探讨了反－α－苯基邻硝基肉桂酸（ＰＮＣＡ）在合成过程中，催化剂、反应温度和反应时间的影响。从中优选出一条理想的合成工艺路线。     

N,N′—间苯基双马来酰亚胺对EPDM交联及网状结构的影响

用ＭＤＲ２０００型无转子流变仪及圆盘仪转子流变仪，差示扫描量热分析法测定并计算了Ｎ，Ｎ′－间苯基双马来酰亚胺（ＭＰＢＭ）对ＥＰＤＭ采用过氧化物硫化体系的交联反应速率常数和表面活化能的影响。结果表明，ＭＰＢＭ能有效地降低交联反应的表观活化能，提高反应速率，增加交联密度，平衡应力－应变及平衡溶胀实验结果也同样表明加入ＭＰＢＭ使ＥＰＤＭ硫化胶的网状结构参数增大。证明具有双官能度的ＭＰＢＭ对于主链饱和的Ｅ     

水介质中N－甲基丙烯酰哌啶的合成

水介质中Ｎ－甲基丙烯酰哌啶的合成陶绪泉，尹汉东，张立云，崔慧，贺媛（聊城师范学院化学系，聊城２５２０５９）Ｎ一甲基丙烯酸吸陡（ＭＡＰ）是用于合成功能高分子的重要单体＂＇。其合成方法可由甲基丙烯酸与亚硫酸氯反应生成甲基丙烯酞氯，然后再与吸陡反应制得［＂...     

p—（N,N—二甲氨基）肉桂酸乙酯在分子聚集体中的光化学行为

本文报道了ｐ－（Ｎ－，Ｎ－二甲氨基）肉桂酸乙酯（ＤＭＡＣ）在十二酸（ＬＡ）聚集体中的光谱和光化学性质。这种肉桂酸衍生物的吸收和发射光谱表现出典型的分子内电荷转移的特征，在十二酸存在下，观察到ＤＭＡＣ激基缔合物荧光，荧光强度随ＤＭＡＣ浓度增加而增加，与普通溶液中的反应相比，十二酸聚集体中的ＤＭＡＣ具有较大的光二聚反应速度。用荧光光谱跟踪反应的结果表明，ＤＭＡＣ激基缔合物具有较ＤＭＡＣ单体更高的光化学     

二安替比林基一间溴苯基甲烷光度法测定锰的研究

研究了二安替比林基－间溴苯基甲烷（ＤＡｍＢＡ）与锰（Ⅶ）的显色反应条件。在磷酸介质中，Ｍｎ（Ⅱ）存在下，ＤＡｍＢＭ与Ｍｎ（Ⅶ）反应生成橙色产物，λｍａｘ＝４８０ｎｍ。ε＝５．１０×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，锰含量在０．１～１．５μｇ／２５ｍｌ符合比尔定律。该体系灵敏度高，具有一定稳定性。食品中的微量锰（Ⅱ）用过硫酸铰氧化为锰（Ⅶ）后用该法测定，结果满意。     

Characterization of drag reduction and degradation effects in the turbulent pipe flow of dilute polymer solutions

Turbulent drag reduction data were obtained at Re = 9000 in a 0.62-cm-I.D. pipe for five Polyox compounds covering a wide range of molecular weights. The concentration dependence of drag reduction was shown to obey an improved form of Virk's drag reduction equation, which was previously applied only to flows in capillary tubes. The efficiency of the drag-reducing polymer additives on a unit concentration basis at infinite dilution was determined by using a characteristic parameter, DR_m/[c], for each compound. A linear relationship was found to exist between this parameter and polymer molecular weight. The polymer degradation data were analyzed through use of a variable related to the dissipated energy in the wall region. The polymer molecular weight was found to decrease as a hyperbolic function of the dissipated energy function. By examining the change of molecular weight with respect to this function, a degradation index characteristic of the entire Polyox polymer family was established. This index may be of general application and provide a method by which the shear stability of various species of drag-reducing polymers may be meaningfully compared.     

丁二烯气相聚合产物分子量分布和粒径分布模型研究

对非均相催化的丁二烯气相聚合,基于聚合物多层模型,考虑催化剂颗粒间活性位初始浓度和粒径分布对聚合物分子量分布和粒径分布的影响,建立了聚合物分子量分布和粒径分布的数学模型。模拟了反应温度、催化剂颗粒间活性位初始浓度和粒径分布等因素的影响,结果表明。随着温度升高,聚合物颗粒平均粒径变小,粒径分布变窄,聚合物分子量变小,分子量分布变宽;催化剂颗粒间的活性组分负载越均匀,聚合物分子量越大,分子量分布和粒径分布越窄;随着催化剂平均粒径变大,聚合物分子量变小,分子量分布变宽,不存在催化剂颗粒粒径分布和聚合物颗粒粒径分布间的复制现象。模型模拟结果与实验结果吻合较好,可用于预测丁二烯气相聚合产物的分子量、分子量分布和粒径分布。     

Studies in the photodimerization of the diglycidyl ether of 4,4′-dihydroxychalcone

In order to elucidate the reaction mechanism involved in the photocrosslinking of epoxide resins containing the 4,4′-dioxychalcone functional group as part of the polymer backbone, the behavior of the monomeric model compound, namely, the digylcidyl ether of 4,4′-dihydroxychalcone, when subjected to UV irradiation has been studied in some detail. The initial photochemical reaction is trans-cis isomerization to a photostationary state, the trans/cis ratios in this state being wavelength dependent. This is followed by a slow dimerization to dimers of the truxillic and truxinic type, the products being mainly formed from the trans isomer under our conditions of irradiation (λ = 350 nm). GPC studies on the irradiated products also reveal the formation of low molecular weight oligomers. Irradiation in the solid phase resulted in the conversion of 37% of the reacted monomer into polymer, whereas irradiation in the solution phase led to 23% of the reacted monomer being converted into low molecular weight polymer. A slow depolymerization of the dimer into the monomeric chalcone is also believed to occur on irradiation at 350 nm.     

高效液相色谱凝胶色谱法测试高分子化合物的研究

采用了高效液相色谱仪与高效凝胶色谱柱,建立了高效液相凝胶色谱分析平台。利用其不同分子量分子在凝胶色谱中表现有不同的保留时间,使用了5种高分子单分散性标准品,根据其保留时间与分子尺寸关系,建立3次拟合校正曲线,快速、高效地获得高分子化合物数均分子量、重均分子量等多种平均分子量,指导了高分子合成方向,为高分子特性研究提供了重要手段。使用了Shodex GPC K-804L8.0 mm×300 mm(A008096)刚性凝胶柱,流动相:氯仿;示差折光检测器,异丙醇稳定性测试,RSD=0.02%,3次拟合曲线,相关系数R=0.99998%,方法稳定可靠。     

Modeling of poly(L‐lactide) thermal degradation: Theoretical prediction of molecular weight and polydispersity index

A mathematical model to describe the molecular weight and polydispersity index (Q) in poly(L ‐lactide) (PLLA) thermal degradation has been developed. Based on the random chain scission mechanism, effects of temperature and time on the molecular weight and polydispersity index are included in this model. It incorporates the degradation and recombination reaction of PLLA thermal degradation, while taking into account the equal probability assumption. The developments of molecular weight and polydispersity index of PLLA polymer in the thermal degradation process were investigated at temperature ranging from 180–220°C, the experimental data show PLLA reaches its thermal degradation equilibrium in 2 h. The simulated results of this model are compared with the measured molecular weight and polydispersity index of the PLLA polymer. The changes of the molecular weight and polydispersity index in the PLLA thermal degradation can be predicted by this model. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2557–2562, 2003     

Photochemistry of azide-phenolic resin photoresists

The photochemistry of a negative working photoresist, MRL, composed of poly(4-hydroxystyrene) and an aromatic monoazide compound, 4-azido-4′-methoxychalcone, has been examined, The major products of photolysis of MRL films are primary amine, secondary amine, and poly(4-hydroxystyrene) with increased molecular weight. The polymeric secondary amines are generated from the nitrene insertion into the backbone carbon-hydrogen bonds of the polymer. Hydrogen abstraction from the polymer by the nitrene with subsequent polymer radical recombination results in the increase in the molecular weight of the poly(4-hydroxystyrene), rendering the exposed areas insoluble in both aqueous alkaline and organic developers. Rapid decrease in the dissolution rate of the poly(4-hy-droxystyrene) with increasing molecular weight is separately ascertained.     

Scission of the poly(methyl methacrylate‐co‐methacrylic acid) chain by excited‐state acridine

A photochemical reaction between acridine and poly(methyl methacrylate‐co‐methacrylic acid) (PMCA) was studied in benzene to build a recyclable polymer photodegradation system. The illumination of acridine in the presence of PMCA with 365‐nm light induced the bleaching of acridine and the degradation of PMCA. The average molecular weight of the degraded polymer decreased rapidly for the first 30 min of the photolysis. A nonvolatile product of this reaction was found to have a 2‐methyl‐2‐propenyl end group. The efficiency of the PMCA scission by this method was 30 times as large as that of poly(methyl methacrylate). These results suggest that an efficient photochemical polymer decomposition system can be built by adding the mixing process of a little methacrylic acid into the synthetic processes of general vinyl polymers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1209–1212, 2005     

Effects of molecular weight distribution on the spinodal temperature of polymer mixtures

The effects of molecular weight distribution on the phase stability of polymer mixtures were explored theoretically and experimentally. Based on the lattice‐fluid theory and volume‐fluctuation thermodynamics, the spinodal conditions for a lattice‐fluid mixture of two polymers with molecular weight distribution were derived. The results indicated that the phase stability of a polymer mixture decreases by increasing the molecular weight distribution of polymers in the blend. To confirm the theoretical results with experiments, the changes in the spinodal temperatures of poly(ethyl methacrylate)/polystyrene (PEMA/PS) blends and tetramethyl polycarbonate/polystyrene (TMPC/PS) blends were examined when each component has a different molecular weight distribution. When the weight‐average molecular weight of each component is the same, a blend composed of polymers having broad molecular weight distribution always exhibited lower phase separation than that composed of polymers having narrow molecular weight distribution at the same blend composition. Copyright © 2004 Society of Chemical Industry     

Dynamic modeling of crosslinking and gelation in continuous ethylene-propylene-diene polymerization reactors using the pseudo-kinetic constant approach

A dynamic model for continuous ethylene-propylene-diene terpolymerization reactors in which crosslinking and gel formation are attributable to reactions between the pendant double bonds of diene units has been developed. The model is applicable to other types of crosslinking reactions such as those due to aging, polymer blending, and vulcanization. The polymer properties at the gel point and in the post-gel region are computed using the numerical fractionation method. Direct application of this method to the prediction of terpolymer properties in the gel or post-gel region can lead to severe numerical problems, due to large differences in order of magnitude of various moments across the generations. These problems are overcome by applying a pseudo-kinetic rate constant method, i.e., by constructing a moment model for a pseudo-homopolymer that approximates the behavior of the actual terpolymer under the long chain and quasi-steady state assumptions. The pseudo-homopolymer model is then used as the basis for application of the numerical fractionation method. We show that the proposed dynamic model is capable of predicting realistic polydispersities and molecular weight distributions even near the gel point with as few as 11 generations, and in the post-gel region with as few as five generations. The largest steady-state polydispersities of the soluble polymer are obtained when the crosslinking rate just exceeds the critical value for gelation. The steady-state polydispersity decreases exponentially in the post-gel region at higher values of the rate constant, while the sol fraction decreases in a more linear fashion. The overall molecular weight distribution (MWD) of the sol is constructed assuming a Schulz two parameter distribution for each generation. For the industrial case of a small number of crosslinks, the first two generations contribute the most to the MWD, which is unimodal. The tail of the MWD is longest near the initial gelation time; the tail is shortened in the post-gel region as higher generations are consumed.     

Synthesis and properties of new polyurethanes with triazene moieties in the main chain

A new diol with bistriazene groups, 1,1′[4,4′‐diphenylether]‐3,3′‐di(β‐hydroxyethyl methyl)‐bistriazene (BTD), was synthesized and characterized. BTD, along with N‐methyldiethanolamine as a chain extender, was used to prepare a segmented polyurethane based on poly(tetramethylene oxide) diol (weight‐average molecular weight = 2000) and 2,4‐tolylene diisocyanate (80:20 v/v 2,4‐/2,6‐isomer mixture). Subsequent quaternization of the amine with benzyl chloride formed the cationomer. The structure–property relationships, including the photochemical behavior of the triazene linkage in these polymers, were investigated with respect to another polyurethane prepared from 4,4′‐diphenylmethane diisocyanate and a bistriazene compound. Photolysis experiments were carried out in polymer solutions and in the film state, and the reduction of the π–π* absorption band, characteristic of the triazene chromophore in ultraviolet spectra, was followed. A kinetic evaluation revealed a first‐order photoprocess. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 385–391, 2005