界面改性对玻纤增强聚丙烯弯曲强度的影响

为了提高玻纤增强聚丙烯（ＰＰ）的界面粘结，分别用Ｂ３０１或硅烷偶联剂对玻纤表面进行了处理，用过氧化物和顺丁烯二酸酐对ＰＰ进行了改性。经处理和改性后，ＰＰ／ＧＦ复合材料的弯曲强度有明显提高，对玻纤增强聚丙烯的界面结构也作了探讨。     

离散物Surlyn对PBT／PP共混体系的力学性能及形态结构的影响

用力学性能测试，ＤＭＡ、ＳＥＭ等方法研究了离聚物Ｓｕｒｌｙｎ对ＰＢＴ／ＰＰ共混体系的力学性能及形态结构的影响。结果表明，在ＰＢＴ／ＰＰ共混体系中引入少量Ｓｕｒｌｙｎ可以改善界面的粘接性，从而改善其力学性能。     

离聚物Surlyn对PBT/PP共混体系的力学性能及形态结构的影响

用力学性能测试、ＤＭＡ、ＳＥＭ等方法研究了离聚物Ｓｕｒｌｙｎ对ＰＢＴ／ＰＰ共混体系的力学性能及形态结构的影响。结果表明，在ＰＢＴ／ＰＰ共混体系中引入少量Ｓｕｒｌｙｎ可以改善界面的粘接性，从而改善其力学性能。当共混体系中ＰＢＴ／ＰＰ的组份比不变（９０／１０）且Ｓｕｒｌｙｎ的含量为６ｐｈｒ左右时，共混物的冲击强度出现极大值；而弯曲强度在Ｓｕｒｌｙｎ含量为１－２ｐｈｒ左右时有最大值。当共混体系中Ｓｕｒｌｙｎ的含量不变（６ｐｈｒ）时，其力学性能随ＰＰ含量的增加而下降。用玻璃纤维增强共混体系，可显著提高力学性能。     

低乙烯含量聚丙烯共聚物结晶成核剂研究

利用ＤＳＣ和偏光显微镜等手段研究了部分成核剂对聚丙烯均聚物（ＰＰ）、低乙烯含量聚丙烯共聚物及聚丙烯／聚乙烯（ＰＰ／ＰＥ）共混物结晶行为的影响，结果表明所用成核剂对ＰＰ和改性ＰＰ具有一定的普适性。聚丙烯共聚物中，由于链结构规整性变差，成核剂的作用显得特别突出，而ＰＰ／ＰＥ共混物中，由于成核剂向ＰＥ相迁移而使其对ＰＰ结晶的成核效率降低。     

聚丙烯粉料固相光接枝马来酸酐的研究

聚丙烯（ＰＰ）由于其优越的性能价格比而具有广泛的用途，但ＰＰ的非极性、易氧化等缺点使其在一些重要领域中的应用受到限制，因此需采用涂层法、等离子体处理、接枝法等方法对ＰＰ改性．其中ＰＰ表面接枝共聚法可使其脱去主链氢原子，引入极性基团，改善染色性和亲水性...     

含刚性链节和脲端基聚醚增韧剂改性环氧树脂的研究———反应活性及力学性能

合成了一系列既含环氧丙烷聚醚（ＰＰＧ）柔性间隔基、又含刚性介晶结构单元的端脲基活性改性剂（ＬＣＥＵＰＰＧ），并对其改性环氧树脂Ｅ ５１／双氰双胺（Ｅ ５１／ｄｉｃｙ）体系的固化反应活性、改性剂含量对增韧体系动态力学性能及冲击性能的影响进行了研究．结果表明：ＬＣＥＵＰＰＧ的加入对固化体系具有明显的增韧作用，冲击强度提高了３～７倍；其对Ｅ ５１／ｄｉｃｙ固化反应具有明显的促进作用，可使固化反应表观活化能（Ｅａ）降低５０～７０ＫＪ／ｍｏｌ、固化温度降低３０～４０℃；体系的玻璃化转变温度（Ｔｇ）略有下降，但模量基本不降低或略有升高；β 转变向低温方向移动．     

含二氮杂萘酮结构聚醚砜酮膜的微波等离子体处理研究

含二氮杂萘酮结构型聚醚砜酮(ＰＰＥＳＫ)是近年来本研究组开发成功的新型耐高温聚合物[1].该聚合物具有优异的力学性能和突出的耐热性,玻璃化转变温度(Ｔｇ)为265～305℃(随砜酮比不同而变化),其结构式如下:ＯＮＮＯＳＯＯＯＮＮＯＣＯ　　研究表明,用ＰＰＥＳＫ制成的气体分离膜对Ｏ2/Ｎ2、ＣＯ2/Ｎ2有良好的气体渗透性和透过选择性[2,3],但由于其亲水性不高进而限制了它在纳滤膜和反渗透膜等方面的应用,因此有必要对其进行改性.目前,常用的膜及膜材料改性的方法有磺化、氯甲基化季胺化、接枝等化学改性和低温等离子体与辐射等物理改性.其…     

橡胶木粉填充LLDPE复合材料的结构和力学性能

用橡胶木粉填充线性低密度聚乙烯(LLDPE),研究了酸、碱溶液预处理木粉的效果和硅烷偶联荆(KH-570)、MMA接枝的天然橡胶胶乳(MGL-30)两种改性剂对橡胶木粉表面改性的效果,以及未粉粒径和填充量等对木粉／LLDPE复合材料力学性能的影响,并用SEM对复合材料拉伸断面的形态结构进行了分析。结果表明：木粉的拉径、木粉填充量和改性荆用量对复合材料的力学性能有较大的影响,经碱溶液预处理再用改性荆改性后的木粉能有效地改善木粉与LLDPE的界面粘结强度,提高橡胶木粉／LLDPE复合材料的力学性能。     

室温交联型硅丙微胶乳的合成研究(1)硅烷单体对聚合稳定性和胶膜性能的影响

采用种子微乳液聚合工艺和单体半连续滴加法合成了室温交联型有机硅改性丙烯酸酯微胶乳，研究了硅烷单体种类和用量及其添加顺序等对聚合稳定和胶膜性能的影响。结果表明，使用含阻碍性铁新硅烷单体（C－1757）可明显抑制体系中的水解－缩合反应，提高聚合稳定性，而且随其用量增加，改性胶膜的交联密度增大，拉伸强度提高；延迟添加C－1757，可进一步提高聚合稳定性，但会降低胶膜的交联密度，拉伸强度先高后低，30／70处有一个最大值，所合成的硅丙微胶乳储存期可达长两年，与C－1757相比，硅烷单体A－174改性的胶膜具有更大的交联密度，而A－171改性的胶膜交联密度偏低，力学性能较差。     

聚丙烯催化合金的相结构研究

聚丙烯 (ＰＰ)由于其价格低廉、性能较好、应用范围广而得到了极为迅速的发展 .然而 ,它的一些缺点也极大地限制了它在一些特殊领域中的应用 .人们为了进一步扩大其应用范围 ,对ＰＰ进行了各种各样的改性 .其中以提高ＰＰ抗冲强度为目的的改性研究进行得最多[1～ 4 ] .这种改性的方法是将ＰＰ和一种以上的其它聚合物以机械共混的方法进行混合 ,使其得到一种宏观上均匀的聚合物共混物 .但是 ,这种混合往往达不到真正均匀的状态 ,因而共混物的抗冲强度提高不显著 .聚合物的性能取决于其内部结构———相态结构和分子结构 ,而相态结构对材料的…     

Catalytic, asymmetric aza-Baylis-Hillman reaction of N-sulfonated imines with activated olefins by quinidine-derived chiral amines

The chiral nitrogen Lewis base, tricyclic cinchona alkaloid derivative TQO, is an effective promoter in the catalytic, asymmetric aza‐Baylis–Hillman reaction of N‐sulfonated imines Ar? CH?NR′ 1 (R′ = Ts, Ms, Ns, SES) with various activated olefins such as methyl vinyl ketone (MVK), ethyl vinyl ketone (EVK), acrolein, methyl acrylate, phenyl acrylate, or α‐naphthyl acrylate to give the corresponding adducts in moderate to good yields with good to high ee (up to 99 %) at ?30 °C or 45 °C in various solvents, including DMF/MeCN (1:1, v/v). The first such reaction of 1 with the simplest Michael acceptor MVK and methyl acrylate has been achieved with excellent enantioselectivity. The adducts derived from MVK and EVK had the opposite absolute configuration to those from acrolein, methyl acrylate, phenyl acrylate, and α‐naphthyl acrylate. A plausible mechanism has been proposed on the basis of previous reports and the authors’ investigations. An effective bifunctional chiral nitrogen Lewis base–Brønsted acid system has been revealed in this type of aza‐Baylis–Hillman reaction.     

Factors influencing the synthesis and the post-modification of PEGylated pentafluorophenyl acrylate containing copolymers

Copolymerization reactions involving oligoethylene glycol acrylate (OEGA) or diethylene glycol acrylate (DEGA) with pentafluorophenyl acrylate (PFPA) have been performed by reversible addition fragmentation transfer (RAFT) polymerization. The effect of the reaction conditions on the nucleophilic acyl substitution reactions of PFPA was studied using a model amine (furfuryl amine). The resulting PEG/PFP functional copolymers were then used as scaffolds to produce a library of polymers by reaction with a range of amines.     

Polyurethane acrylate-stabilized cholesteric liquid crystal dispersions

Polymer stabilized cholesteric liquid crystals (PSCLCs) have been fabricated based on various structures of polyurethane acrylate (PUA) as well as conventional acrylate polymer, namely poly(1,6-hexanediol diacrylate). For PUA stabilized films, the transmittance spectra of cured films were essentially identical to those of uncured films, with no 'dead' reaction; whereas, using acrylate polymer; reflection greatly decreased upon curing and showed significant 'dead' reaction after the cessations of irradiation. The structure of PUA also had significant effects on the electro-optic performance, and these effects are interpreted in terms of elasticity and interfacial interaction between the polymer and LC.     

新型环氧丙烯酸树脂增韧剂的合成

用马来酸酐和聚乙二醇1000合成具有反应活性端基的聚乙二醇,用红外与核磁共振进行了表征,并用其对环氧丙烯酸树脂进行改性;研究反应温度、反应时间对反应及产物性能的影响;用红外对反应性聚乙二醇和环氧丙烯酸树脂的固化物进行分析.结果表明,反应性聚乙二醇参与了环氧丙烯酸树脂的固化反应,可在交联网络中构成不同长度的柔性链段,显著地提高了环氧丙烯酸树脂的冲击强度.     

氟喹诺酮作为钯催化Heck反应有效配体的研究

研究了氟喹诺酮作为钯催化Heck反应的有效配体. 碘苯、溴苯和其它芳基卤衍生物与丙烯酸丁酯、苯乙烯等取代乙烯类化合物在钯和氟喹诺酮的催化下发生Heck反应. 讨论了配体、催化剂用量、碱和溶剂对Heck反应产率的影响. 该反应的最优化条件是: 钯源为Pd(OAc)2 (0.1 mol%), 诺氟沙星作为配体(0.2 mol%), K2CO3作为碱, DMA作为溶剂, 取代碘苯及溴苯和它们的衍生物与丙烯酸丁酯、苯乙烯等乙烯基化合物的反应均可以得到高收率的目标偶联产物.     

Calculation of kinetic parameters and sequence distribution from pyrolysis gas chromatographic data of styrene-methyl acrylate copolymers

Styrene-methyl acrylate copolymers have been investigated by pyrolysis gas chromatography. The pyrolysis product distribution, ranging from methyl acrylate monomer to styrene trimer, was measured and introduced into a mathematical model described previously. Applying this model, the sequence distribution and the rate constants of the degradation reactions were obtained. The results show that the sequential arrangement is important in the thermal decomposition of styrene-methyl acrylate copolymers. In most cases the rate constant of a product release reaction depends considerably on the nature and sequence of the monomer units in the product molecule, as well as on the nature of the monomer unit remaining on the macroradical end, from which the molecule was released.     

Surface modification of polymers. II. Grafting with glycidyl acrylates and the reactions of the grafted surfaces with amines

The surface of low density polyethylene has been grafted with glycidyl acrylate and glycidyl methacrylate by photoinitiation. ESCA measurements on the grafted surface showed a 72% coverage for glycidyl acrylate and 52% for glycidyl methacrylate after 10 min of grafting with UV irradiation. ATR–IR showed a 10 times more extensive grafting for glycidyl acrylate than for glycidyl methacrylate after 10 min of grafting, indicating reaction to deeper layers. Acetone and ethanol were used as solvents: acetone yielded slightly more grafting at the surface. The grafted surfaces were reacted with 2M solutions of aniline and propylamine in ethanol. After 4 h reaction at 60°C, with aniline 52% of the epoxy groups while for propylamine 96% of the groups were consumed, as measured with ATR–IR.     

丙烯酸酯三元共聚物负载硫铂络合物的合成及催化性能

丁二醇二丙烯酸酯、丙烯酸甲酯、丙烯酸β-氯乙酯或丙烯酸ω-氯己酯进行三元共聚,合成了两类4种带ω-氯侧基的交联型聚丙烯酸酯.它们以乙硫醇硫醚化,再与氯亚铂酸钾反应,得到4种交联型聚丙烯酸酯负载的硫铂络合物.这些络合物对癸烯-1、十二烯-1、苯基烯丙醚、苯乙烯与三乙氧基硅烷的硅氢加成反应具有良好的催化活性.讨论了温度、催化剂用量对催化性能的影响及催化剂的重复使用情况.     

γ-radiation-initiated emulsion polymerization of n-butyl acrylate and of methyl methacrylate

We have investigated the γ-radiation-initiated polymerization of n-butyl acrylate (BA) and of methyl methacrylate (MMA) in aqueous emulsions stabilized with sodium lauryl sulfate (SLS). The reaction rate, as measured by a nonabsolute thermocouple technique, varies as the square root of emulsifier concentration for both monomers. In the case of BA, the dose rate exponent of the reaction rate is 0.7 ± 0.3, whereas the corresponding value for MMA is approximately 0.4. The overall activation energy of the BA polymerization is close to zero, whereas for MMA a value of 4.8 ± 2.1 kcal/mole has been found. The poly(butyl acrylate) molecular weight is effectively independent of soap concentration and of dose rate but decreases as the reaction temperature is increased in the range 30–70°C. The general conclusion drawn from this work is that these radiation-induced emulsion polymerizations differ little from conventionally initiated systems insofar as the reaction kinetics are concerned. Poly(butyl acrylate-g-methyl methacrylate) copolymers have been prepared by a direct irradiation method involving a poly(butyl acrylate) prepolymer seed latex. Some physical properties of this material have been examined.     

迈克尔加成法合成乙二胺枝状化合物

以乙二胺和丙烯酸异辛酯为原料,甲醇为溶剂,在无催化剂条件下,经迈克尔加成反应合成了低代的树枝状化合物.探讨了反应条件对产率的影响,发现适宜的条件为:n(乙二胺)∶n(丙烯酸异辛酯)=1∶5.0~6.5,反应温度为5~10℃,反应时间为48 h左右,产率可达55%.