C1～C3正构醛、醇在质子转移反应飞行时间质谱中的产物离子特征分析

为分析C₁～C₃正构醛、 醇化合物在质子转移反应飞行时间质谱(PTR-TOF MS)中的产物离子特征, 考察了不同E/N值(E: 电场强度, N: 气体分子数密度)下C₁～C₃正构醛、 醇的产物离子种类和强度的变化. 结果表明, 低分子量正构醇类(甲醇、 乙醇和丙醇)倾向于形成质子化聚合物[nMH]⁺及其失水离子[nMH-H₂O]⁺, 且随着E/N值升高, 醇类会产生较多裂解碎片和多聚体离子. 低分子量正构醛(甲醛、 乙醛和丙醛)主要产生质子化产物[MH]⁺和一水合质子化产物[M·H₃O]⁺, 高E/N值(>125 Td)会抑制甲醛质子化, 也会抑制其加合产物的生成. 乙醛倾向于形成水加合物, 且随着E/N值增高, 质子化乙醛与一水合质子化乙醛的变化趋势相反. 另外, 丙醛在较高的E/N值下会产生一系列聚合物, 如[MH·C₂H₅]⁺和[2MH]⁺. 通过分析C₁～C₃正构醛、 醇的质子转移反应特征及产物离子形成过程, 获得了C₁～C₃正构醛、 醇的特征离子和对应的最佳E/N设置值, 为低分子量醛、 醇的定性分析提供了重要依据.     

一种带有芳基双亲双官能度引发剂的合成

双亲聚合物已广泛地应用于许多领域^[1],但其制备困难^[2~4].     

苯甲酸及其酯类衍生物的分子印迹机理的研究

分子印迹聚合物(M IP)是一种具有分子识别能力的新型高分子材料^[1～3].对其研究的重要问题之一是如何获得对相应模板化合物具有特异性结合的聚合物,这除了受模板分子结构特征的影响外,同时在很大程度上还受各种聚合物制备条件的影响,比如功能单体^[4～6]、溶剂^[7]及辅助金属离子的影响^[8]等.我们成功地通过计算模板分子与功能单体间的相互作用,预测了一些模板分子的印迹原性(产生印迹效应的性质)的强弱^[9],同时对几十种小分子化合物的分子印迹原性与结构之间的关系进行了讨论^[10].本文以苯甲酸、对氨基苯甲酸、对羟基苯甲酸及其酯的衍生物(结构见下式)为模板,在不同的功能单体和溶剂体系中制备了相应的分子印迹聚合物,研究了模板分子中不同取代功能基的印迹作用的相对强弱,探讨了功能基的印迹作用强弱与聚合反应体系溶剂极性间的相关性.     

一种控制合成星型聚合物的活性核结构的方法

Eschwey^[1]用丁基锂与二乙烯基苯作用得到活性核,由于核分子量大,悬吊双键多没有实用价值。我们用不同长度活性预聚物代替丁基锂,有效地控制了活性核的尺寸与悬吊双键数,为控制合成凝胶星型高聚物的结构提供了一种方法,研究了影响活性核的因素。用这种方法得到的星型聚合物带有两种长度的支链,具有特殊性质^[2]。     

水介质中丙烯酸的分散聚合

丙烯酸聚合物及其与其它水性单体的共聚物是一类非常重要的水溶性高分子化合物, 具有许多优异的性能, 广泛应用于环保、 石油化工、 造纸和食品卫生等行业^[1]. 丙烯酸聚合物一般采用水溶液、 反相悬浮及反相乳液法制备, 但这些方法存在诸如反应体系粘度高, 不易散热、 使用不方便, 由于使用有机溶剂和表面活性剂易对环境造成二次污染等问题^[2].近些年, 由日本率先研制开发的以水为溶剂分散型高浓度﹑高分子量的新型水溶性高分子产品, 克服了传统合成方式和产品剂型等诸多问题, 极大地拓宽了其使用领域[^3~5]. 有关水介质中水溶性单体分散聚合的研究报道很少^[6~8].而针对于丙烯酸在水介质中的研究报道则更少[^9] , 大部分工作为专利文献.     

氧化-还原引发剂引发苯乙烯超浓乳液聚合的研究

以过氧化羟基二异丙苯(CHPO)和四乙烯五胺(TEPA)为氧化-还原引发剂,以十二烷基硫酸钠(SDS)为乳化剂,十六醇(CA)为共乳化剂,通过超浓乳液聚合方法制备了聚苯乙烯乳胶粒子.探讨了乳化剂浓度及配比、分散相体积分数、引发剂种类、引发剂浓度及配比和温度等各因素对乳液稳定性、聚合速率、乳胶粒子大小、形态及分布的影响.用透射电子显微镜(TEM)观察了乳胶粒子的形态,用粘度法测定了聚苯乙烯的粘均分子量.考察了苯乙烯进行超浓乳液聚合的反应动力学,求得在30℃时聚合速率方程为Rp=K[M]^0.36[I]^0.49[E]^0.72,表观活化能为19.72kJ/mol.所得乳胶粒子的直径在0.1～0.3μm之间,粘均分子量在2×10⁶～4×10⁶之间.为低温下实现超浓乳液薄层聚合提供了参考数据.     

固相氯化法氯化聚乙烯晶粒尺寸的X射线衍射研究

晶粒尺寸的测定常用付里叶变换法^[1]和积分宽度法^[2],这两种方法都要求样品相应于某个晶面至少存在三个级别的衍射峰,而对聚合物来说,观察到高级衍射峰的情况是很少见的.方差函数法不要求样品存在三个级别的衍射峰,而且方法简单,曾广泛用于金属材料晶粒尺寸和点阵畸变的测定^[3-5],但在聚合物材料中的应用甚少^[6].本文采用方差函数法对固相氯化法氯化聚乙烯(CPE)和原料聚乙烯(PE)的晶粒尺寸和点阵畸变参数进行了研究,得到了较为满意的结果.     

硝基磺酚C光度法测定蛋白质的研究

蛋白质的定量分析是生化研究、临床化验和食品检验等领域经常涉及的内容.以有机小分子作光谱探针测定蛋白质,如甲基橙^[1,2]、考马斯亮蓝G-250^[3]、溴酚蓝^[4]、溴甲酚绿^[5]和偶氮胂Ⅲ^[6]等已得到研究.     

二苯并噻吩及其氧化物与离子液体相互作用的理论研究

采用密度泛函理论方法比较了DBT/DBTO₂和[BMIM]⁺[PF₆]^-/[BMIM]⁺[BF₄]^-的相互作用。对最稳定的[BMIM]⁺[PF₆]^-、[BMIM]⁺[PF₆]^--DBT、[BMIM]⁺[PF₆]^--DBTO₂、[BMIM]⁺[BF₄]^-、[BMIM]⁺[BF₄]^--DBT、[BMIM]⁺[BF₄]^--DBTO₂进行了NBO和AIM分析。结果表明,DBT和[BMIM]⁺[PF₆]^-/[BMIM]⁺[BF₄]^-中的咪唑环彼此相互平行,NBO和AIM分析表明它们之间发生了π-π相互作用。H1'和H9'形成的F…H氢键有利于π-π堆积作用的形成。DBTO₂倾向于趋近C2-H2和甲基基团形成O…H相互作用;DBTO₂优先吸附在[BMIM]⁺[PF₆]^-/[BMIM]⁺[BF₄]^-。在模拟油中,[BMIM]⁺[PF₆]^-和[BMIM]⁺[BF₄]^-离子液体对DBTO₂的萃取能力大于DBT,其原因是可能是DBTO₂具有较大的极性和O…H与F…H的氢键作用。     

植物生物分子的电分析化学研究Ⅷ.秋水仙碱的微分脉冲极谱行为及分析应用

秋水仙碱是近年来新发现的有前途的抗癌植物有效成分。秋水仙碱的测定方法,如容量滴定法^[1]、电位滴定法^[2]、紫外分光光度法^[3]、荧光分析法^[4]和高效液相色谱法^[5]等,手续均不太简便。电化学分析研究秋水仙碱主要有阳极伏安法^[6]和交流极谱法^[7],前者因使用固态电极,重现性较差。后者用非水溶剂作介质,灵敏度不高。     

端羟基聚丁二烯型聚氨酯/聚苯乙烯(或聚甲基丙烯酸甲酯)互穿网络的形态和玻璃化转变

The morphology structure and glass transition behavior of polybutadiene-based polyuretha-ne/polystyrene (or polymethyl methacrylate) interpenetrating polymer network (PU(HTPB)/ PSt-IPN, PU(HTPB)/PMMA-IPN) were investigated by TEM and DSC. TEM showed that the phase inversion of PU(HTPB)/PSt-IPN occurred in the concentration of 25% PU(HTPB), and the size of dispersed phase domains of the IPN formed was smaller in the concentration about 50% PU(HTPB). Increasing DVB content or proportion of NCO to OH enhanced in-terpenetration of two components. All of IPN samples exhibited special cellular structure. According to the fact that PU(HTPB) was formed first,a formation mechanism of the struc-ture was proposed.     

端羟基聚丁二烯型聚氨酯/聚苯乙烯(或聚甲基丙烯酸甲酯)互穿网络的形态和玻璃化转变

互穿聚合物网络(IPN'S)已经成为高聚物共混改性,高聚物间相容性的一个重要研究领域,IPN材料的宏观性能与其微观形态有着密切的关系,如能通过改变结构、组成、交联密度及合成条件等因素来控制IPN的形态,则就可以入为地制备各种性能优良的材料。本文用透射电镜和差示扫描量热仪对同步法合成的端羟基聚丁二烯型聚氨     

Room temperature synthesis and mechanical properties of two kinds of elastomeric interpenetrating polymer networks based on castor oil

Two kinds of interpenetrating polymer networks (IPNs) composed of two-component polyurethane (PU) and vinyl or methacrylic polymer (PV), namely, (polyether-castor oil)PU/PV IPN(I) and (polybutadiene-castor oil)PU/PV IPN(II), were synthesized at room temperature using benzoyl peroxide and N,N-dimethylaniline as redox initiator and dibutyltin dilaurate as catalyst. The former IPN was prepared by polymerization of castor oil, NCO-terminated polyether and vinyl or methacrylic monomer together and the latter IPN was obtained by polymerization of castor oil, NCO-terminated polybutadiene, NCO-terminated castor oil and vinyl or methacrylic monomer together. Various synthesis conditions affecting mechanical properties of the two kinds of IPNs were studied. Acrylonitrile (AN) is a good monomer for synthesizing IPN(I), but is a poor monomer for preparing IPN(II). At optimum conditions for the synthesis, both the (polyether-castor oil)PU/PAN IPNs and the (polybutadiene-castor oil)PU/polystyrene (PSt) IPNs possess permanent set about 10%, tensile strength over 13 and 11 MPa and ultimate elongation over 240% and 270%, respectively, thus behaving as elastomers. TEM micrograph of a (polybutadiene-castor oil)PU/PSt IPN showed a microphase separation in the IPN.     

聚醚聚氨酯/环氧树脂互穿网络聚合物的研究(Ⅱ)

合成了不同类型聚醚聚氨酯/环氧树脂(PU/EP)互穿网络聚合物(IPN),通过改变PU中聚乙二醇分子量、3OH/2OH及NCO/OH比值等,研究IPN组份间分子混合程度,采用电镜、动态力学分析及应力应变等测试方法表征。结果表明:聚乙二醇分子量降低及3OH/2OH、NCO/OH比的提高,可使相容性提高,材料力学性能增强。     

Interpenetrating polymer networks from polyurethanes and methacrylate polymers. I. Effect of molecular weight of polyols and NCO/OH ratio of urethane prepolymers on properties and morphology of IPNs

Two types of reinforced elastomeric interpentrating polymer network (IPN) were prepared by simultaneous polymerization and crosslinking in solution. The first type consisted of polyurethane-poly(methyl methacrylate) (PU/PMMA), and the second, of polyurethane-poly(methyl methacrylate-methacrylic acid) PU/P(MMA–MAA) of constant composition (90/10) and (80/20) by weight, respectively. The members of each type differed in the NCO/OH ratio of the PU prepolymer and the molecular weight (MW) of the polyol in the PU component because we wished to investigate systematically the effect of changing the NCO/OH ratio and MW of the polyol on the mechanical properties and morphology of the resulting IPNs. The mechanical properties, particularly the modulus of both tyes of IPN, increased with increasing NCO/OH ratio and decreased with increasing MW of the polyol in the PU. The morphology of the IPNs was studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Improved phase compatibility and decreasing extent of phase separation was observed in both types of IPN with increasing NCO/OH ratio and decreasing MW of the polyol used in the PU. These results may imply that improved interpenetration results from increasing the NCO/OH ratio and decreasing the MW of the polyol in the PU component. The fact that the effect is more pronounced with the type of PU-P(MMA–MAA) IPN can be rationalized as due to the additional hydrogen bonding between the carbonyl in the carboxyl groups and the urethane or urea groups in the PU component.     

聚氨酯互穿聚合物网络阻尼性能研究进展

介绍了聚氨酯互穿聚合物网络（ＰＵ ＩＰＮ）作为阻尼材料的研究进展,分别讨论了聚氨酯（ＰＵ）／环氧树脂（ＥＰ）ＩＰＮ和ＰＵ／乙烯基聚合物ＩＰＮ的阻尼性,以及影响阻尼性能的因素,并比较了不同类型的ＰＵ ＩＰＮ的优缺点及新的可能的探讨方向。     

Polyurethane/polyethyl acrylate interpenetrating polymer networks

The thermal decomposition kinetics of polyurethane/polyethyl acrylate interpenetrating polymer networks (PU/PEA IPN) were studied by means of thermogravimetry and derivative thermogravimetry (TG-DTG), and compared with those of polyurethane (PU) and polyethyl acrylate (PEA). The decomposition temperature (T _i) of PU/PEA IPN was found to be higher thanT _i of PEA, but lower thanT _i of PU. Thermal decomposition kinetic parameters,n andE, estimated using Coats-Redfern method, are found for PU/PEA IPN, PU and PEA to be 1.6, 1.9 and 1.1, and 196.6, 258.6 and 139.2 kJ mol^–1, respectively. The results show that PU/PEA IPN is neither a simple mixture of PU and PEA nor a copolymer of them. The mechanism of thermal decomposition of PU/PEA IPN is different from those of PU and PEA. The special network in PU/PEA IPN effectually protects weak bonds in the molecular chain of PU and PEA.We express our thanks to Dr. Yaxiong Xie and Zhiyuong Ren for their help in this work,     

Natural and acid-treated attapulgite reinforced soybean oil-based polyurethane/epoxy resin interpenetrating polymer networks

Soybean oil-based polyurethane (PU)/epoxy (EP) interpenetrating polymer network (IPN) nanocomposites were prepared with natural attapulgite (N-ATT) and acid-treated attapulgite (A-ATT). The structure, glass transition, damping properties, thermal stability, mechanical properties and morphology of PU/EP IPN/ATT nanocomposites were characterized by X-ray diffraction (XRD), dynamic mechanical analysis (DMA), thermogravimetric analyzer, universal test machine and scanning electronic microscope (SEM). XRD showed that interaction with PU did not change the crystal structures of ATT. DMA results revealed the addition of ATT improved the glass transition temperature of the soybean oil-based PU/EP IPN, especially for A-ATT. However, the incorporation of ATT slightly decreased the damping properties of the soybean oil-based PU/EP IPN. Tensile tests confirmed that A-ATT had a significant reinforcement effect on the soybean oil-based PU/EP IPN. The tensile strength of the soybean oil-based PU/EP IPN increased by 56% with the addition of 4 mass% A-ATT. SEM demonstrated the relatively uniform dispersion of both N-ATT and A-ATT in the soybean oil-based PU/EP IPN matrix.

     

PU/PSt型复合乳液粒子热力学平衡形态预测

以水性聚氨酯分散液为种子采用无皂乳液聚合新技术合成出了具有核壳结构的聚氨酯 聚苯乙烯(PU PSt)型复合聚合物乳液 .采用界面张力简化计算方法 ,通过界面自由能变化最小的热力学判据对合成的复合乳液粒子的热力学平衡形态进行了预测 .并利用透射电子显微镜和接触角法测定的膜的表面极性对其进行了证实 .结果表明 ,界面自由能变化的最小判据可以推广到PU PSt体系 ,文中给出的界面张力的简化计算方法是可行的 .     

EP-g-PU IPN结构阻尼材料

采用-NCO封端的聚氧酯(PU)预聚物,制备了环氧树脂-聚氨酯互穿网络(EP-g-PU IPN);通过添加受阻酚四[β-(3,5-二叔丁基-4-羟基苯基)丙酸]季戊四醇(AO-60)制备了AO-60/EP-g-PU IPN.通过FT-IR、DMA、SEM分别研究了改性分子链的基团变化、改性体系的动态性能及断裂面的形态,...