金属-橡胶硫化粘接研究进展

综述金属 -橡胶胶粘剂及粘接技术进展 ,回顾其发展过程 ,分析不同粘接体系的优缺点 ;探讨金属-橡胶粘接过程中的某些问题及影响粘接的多种因素 ,并对下一步的研究发展提出了部分建议。     

稀土催化异戊二烯-马来酸酐交替共聚

研究了含氟基团的引入对聚醚醚酮（PEEK）的介电常数、溶解性、结晶性和力学性能等的影响，结果表明，这种含氟聚芳醚酮在保持PEEK良好机械性能的条件下，介电常数达到2．7，且频率依赖性小，成膜性能好，成本比相应的含氟PI低5－10倍，有望成为一种极有实用价值的电子封装材料，同时利用合成的含氢氟单体合成了一系列不同－CF3取代基含量的聚芳醚酮共聚物，研究了聚芳醚酮共聚物的介电常数与聚合物结构单元中－CF3取代基含量的关系，结果表明，聚芳醚酮共聚物的介电常数的介电常数随聚合结构单元中－CF3取代基含量的增加而线性降低。     

丁吡橡胶的特性粘数分子量关系

丁呲橡胶(丁二烯—2-甲基5-乙烯基吡啶共聚物)是最近发展起来的合成橡胶的一个新品种,它的特性粘数分子量关系,文献中尚无报道。作者等用丁二烯与2-甲基5-乙烯基吡啶(聚合配种比是75:25)在5°进行乳液共聚所得试样,经丙酮提取后,在甲苯溶液中以甲醇作沉淀剂连续进行了三次沉淀分级,选取其中六个级份溶于甲苯,在25.0°作渗透压和粘度测量,实验方法同前。渗透压数据用(π/C)~(1/2)对C作图法处理,如图1,这样得到的分子量和第二维利系数值列于表1;粘度数据仍按通用的处理方法,得到的结果也列在表1。     

稀土络合催化苯乙烯-马来酸酐配位共聚

本文首次应用稀土配位催化剂NdL_3-A1(i-Bu)_3,在苯溶剂中,50℃下使苯乙烯-马来酸酐共聚,制得富于交替,数均分子量高达6—8.5×10~5的白色粉末共聚物。系统地研究了共聚合反应的特征及动力学行为,共聚合反应具有低的表现活化能(10.5kJ/mol),并且不被对苯二酚所阻聚。不同配体稀土(钕)催化剂活性次序为:Nd(naph)_3>Nd(P_(507))_3～NdCl_3·6H_2O>Nd(P_(204))_3>Nd(acac)_3·3H_2O,并且,初步揭示了共聚合反应的机理——两种单体形成电荷转移络合物参与增长的配位共聚。     

2-巯基苯并噻唑稀土配合物的合成、表征及橡胶硫化促进性能研究

在无水乙醇溶剂中,以稀土氯化物与2-巯基苯并噻唑钠盐反应,合成了8种稀土含硫有机配合物.通过元素分析、红外光谱和热重分析,确定了配合物的组成为RELCl2*RE(OH)3*xH2O(L=2-巯基苯并噻唑, RE= La～Gd, Y, 除Pm外,x=0,2～4 );并对合成的镧配合物进行了橡胶硫化促进性能研究,结果表明,该类配合物具有较好的硫化促进性能和改善硫化胶物理机械性能的特性.     

橡胶硫化促进剂的研究进展

作为橡胶加工成形过程中最重要的步骤之一,橡胶硫化直接影响橡胶制品的性能。与单用硫黄相比,少量的促进剂与硫磺配合可以极大地提高硫化速率,改善硫化胶的性能。但目前橡胶硫化促进剂普遍具有潜在的人类健康和环境风险问题,同时硫化促进效能较低、功能单一。因此,开发无毒、无或少氧化锌、高效、多功能的新型硫化促进剂对橡胶工业具有非常重要的意义。本文首先简要介绍了橡胶硫化促进剂的发展历程,然后综述了近年来新型橡胶硫化促进剂的研究进展(包括离子液体促进剂、新型二硫代氨基甲酸盐类促进剂、稀土促进剂、以及含新型副促进剂的硫化并用体系等),并对橡胶硫化促进机理、新型橡胶硫化促进剂的设计进行了展望。     

环保芳烃油填充改性反式-1,4-丁二烯-异戊二烯共聚橡胶的研究

采用不同份数(0~15phr)的环保芳烃油(TDAE)改性反式-1,4-丁二烯-异戊二烯共聚橡胶(TBIR),研究了充油份数对TBIR胶、TBIR混炼胶及硫化胶性能的影响。结果表明,随充油份数的增加,TBIR胶和TBIR混炼胶的门尼粘度降低,混炼胶挤出物外观形貌改善,Payne效应减弱。充油改性TBIR硫化胶(5~10份TDAE)耐裂口引发性提高23倍以上,损耗降低,撕裂性能提高,硬度下降,拉伸强度及定伸模量基本不变;TEM测试表明,充油改性TBIR硫化胶的炭黑分散性改善;DSC测试表明,硫化胶中存在TBIR的微弱结晶熔融峰。环保芳烃油的充油份数为10phr时,胶料综合性能最好。     

天然5,7-二羟基-3-异戊烯基黄酮与5-羟基-3-异戊烯基黄酮的全合成

以2,4,6-三羟基苯乙酮和2,6-二羟基苯乙酮为原料, 分别通过甲基保护酚羟基、 苯甲酰氯酰化、 Bake-Venkataraman重排、 异戊烯基化、 酸催化关环及EtSLi脱去甲基等6步反应, 以高收率完成了天然5,7-二羟基-3-异戊烯基黄酮(1a, 收率80.6%)和5-羟基-3-异戊烯基黄酮(1b, 收率84.9%)的全合成, 所有化合物均经 ¹H NMR 和 ¹³C NMR表征确定. 通过密度泛函理论方法对目标产物(1a和1b)的生物活性进行了预测. 结果表明, 3位异戊烯基侧链的存在能大大增强化合物相应的生物活性, 而且是化合物生物活性增强必需的取代基. 另外, 目标产物1a的生物活性高于产物1b, 归因于黄酮类化合物分子中A环上的7-OH属增效基团, 起到增强生物活性的作用, 化合物1a分子中A环上有7-OH, 而化合物1b分子中则无该基团. 本合成方法对其它3-烃基黄酮类天然化合物的合成具有潜在的适用性, 所预测的生物活性结果为3-烃基黄酮类化合物的构效关系研究奠定了基础.     

稀土-8-羟基喹啉-核酸体系的荧光特性

报道了钪、钇、镧等三价离子在核酸存在下与８羟基喹啉（８ＨＱＬ）形成三元体系的荧光特性，对比核酸和稀土离子的种类对荧光发射的影响。结果表明有鱼精子ＤＮＡ（ＤＮＡｆｓ）＞小牛胸腺ＤＮＡ（ＤＮＡｃｔ）＞酵母ＲＮＡ（ＲＮＡｙ）的荧光增强顺序；稀土离子与８ＨＱＬ的摩尔比随稀土离子的种类发生变化，与ＲＥ３＋８ＨＱＬ配合物的摩尔比有较大差异。     

1-甲基-1-丙基-3-丁烯基环戊二烯基稀土二氯化物的合成

丁烯基环戊二烯基稀土氯化物;1-甲基-1-丙基-3-丁烯基环戊二烯基稀土二氯化物的合成     

可溶性稀土聚乙炔的某些结构特征

本文利用UV、IR、Ramaan、ESR和X射线衍射等方法研究了可溶性聚乙炔的某些结构特征。发现非结晶的可溶性聚乙炔的光谱和波谱性质与结晶的膜状及粉末状聚乙炔有明显的差异,可能是由于它们的分子量相差悬殊造成的。实验结果表明,线型聚乙炔可能存在可溶的临界分子量,其值在=500 左右。     

SOLUBLE POLYACETYLENE OBTAINED WITH RARE-EARTH CATALYST AND SOME ASPECTS OF POLYMERIZATION MECHANISM

Soluble polyacetylene (PA) with well--defined nature has been synthesized with catalyst system Nd(i-OPr)_3/AIR_3 (R=C_2H_5-, i-C_4H_9-) and characterized by IR, Raman and ESR Spectra etc. Number average molecular weight of the soluble specimen were determined by VPO to be about 500g/mol. or lower. The IR and NMR spectra and end group analysis of" the soluble polyacetylene fully demonstrate that polymerization of acetylene with rare-earth catalyst is realized through monomer insertion between the transition metal-carbon bond.     

COORDINATION COPOLYMERIZATION OF STYRENE WITH MALEIC ANHYDRIDE BY RARE-EARTH COORDINATION CATALYSTS

The study on coordination copolymerization of styrene (S) with maleic anhydride (MA) by rare-earth coordination catalysts, NdL_3-Al(i-Bu)_3, has been successfully carried out for the first time. Some features, kinetic behavior, and mechanism of the SMA copolymerization by Nd(naph)_3-Al(i-Bu)_3 system are described and discussed. The copolymex of styrenemaleic anhydride prepared by the NdL_3-Al(i-Bu)_3 systems in benzene at 50℃ is an alternating-rich white powder having high number-average molecular weight of 6—8.5×10~5. The overall activation energy for the polymerization was found to be 10.5KJ/mol. The polymerization was not suppressed by addition of hydroquinone. The catalytic activity of various ligands in NdL_3 for the copolymerization decreases in the following order: Nd (naph)_3>Nd-(P_(507))_3～NdCl_3-6H_2O>Nd(P_(204))_3>Nd(acac)_3. 3H_2O. The experimental results are explained based on a mechanism to be the coordination-type copolymerization in terms of the participation of a monomer-monomer c     

SYNTHESIS AND PROPERTIES OF HOMOPOLYMER AND COPOLYMERS OBTAINED FROM 1-OCTADECENE WITH ZIRCONOCENE CATALYSTS

Studies related to the behavior of different metallocene catalysts for the homopolymerization of 1-octadecene andits copolymerization with ethylene will be presented. The metallocenes: rac-Et(Ind)_2ZrCl_2, rac-Me_2Si(Ind)_2ZrCl_2 andPh_2C(Flu)(Cp)ZrCl_2 were chosen for the homopolymerization study. They show important differences in catalytic activity athigh temperatures (≥70℃), with rac-Et(Ind)_2ZrCl_2 showing the highest activity. At lower temperatures (≤30℃) thedifferences are negligible. For the copolymerization of ethylene with 1-octadecene only the catalysts rac-Et(Ind)_2ZrCl_2 andrac-Me_2Si(Ind)_2ZrCl_2 were studied. The results show that their catalytic activity is just like that for the homopolymerizationof 1-octadecene, with higher activity for the metallocene with the Et-bridged catalyst. ~(13)C-NMR analysis shows that thecomposition of the copolymerization products depends on the catalytic systems. Copolymers obtained with rac-Me_2Si(Ind)_2ZrCl_2 have greater comonomer incorporation. Thermal analysis shows that poly-1-octadecene synthesized withthe catalyst rac-Et(Ind)_2ZrCl_2 is very dependent on the polymerization temperature. The homopolymer obtained at 70℃presents two endothermal peaks at 41℃ and 53℃, as compared with the one obtained at 30℃ which presents one wider peakwith a maximum at 67℃. For the catalyst rac-Me_2Si(Ind)_2ZrCl_2 this trend is not observed. The type of metallocene and thereaction time do not significantly change the intrinsic viscosity, but the polymerization temperature changes it drastically,giving higher values at lower temperature. Viscosity measurements on the copolymers show that an increase of comonomerconcentration in the feed reduces the molecular weight of the copolymer, and it was also found that for homopolymer, themolecular weight is independent of the catalytic systems.     

稀土络合催化苯乙烯均聚及其与二乙烯苯共聚

应用稀土化合物:环烷酸钕Nd(naph)_3和二(2-乙基己基)磷酸钕Nd·(P_(204)_3分别与三异丁基铝Al(i-Bu)_3组成络合催化剂引发苯乙烯均聚及其与二乙烯苯共聚。适宜的聚合温度为50℃:[Nd]=3×10~(-5)mol/ml;[M]=3×10~(-3)mol/ml;Al/Nd=10(摩尔比),并且催化剂按以下次序配制:钕化合物→溶剂→苯乙烯→三异丁基铝,苯乙烯的转化率在90％以上。溶剂种类及聚合条件不同,制得的聚苯乙烯可为白色或黄色粉末状无定形聚合物,分子量几百至上万。聚合体系中添加PeCl_3能抑制黄色产生。在共聚反应中,二乙烯苯比苯乙烯显示较高的反应活性。     

三氯化铁掺杂稀土聚乙炔的电性能

自从1981年A.Prón等人用三氯化铁掺杂钛系聚乙炔而得到高电导率掺杂聚乙炔以来,对此掺杂聚乙炔的低温电性能已作了一定的研究。不同作者所报道结果可分为两类:一类报道各种掺杂量聚乙炔的电导率均随温度降低而单调减少;另一类则观察到随温度的降低电导率约在200K时出现最大值(增加5%),接着电导率降低。新近我们报导了三氯化铁掺杂的稀土聚乙炔的基本特性。本文进一步对此掺杂稀土聚乙炔的低温电性能作了研究,观察到与上述两种情况相似但不完全相同的结果。     

希土(Ⅲ)—氨基多羧酸配位热的测定

本文测量了置换反映:RE~(3+)+MgY~(2-)=REY~-+Mg~(2+)和RE~(3+)+MgZ~(3-)=REZ~(2-)+Mg~(2+)在离子强度I=0.10MNaClO_4,298.15K时的焓变(RE=La、Ce、Pr、Nd、Sm、Eu、Gd、Dy、Ho、Yb、Y。Y~(4-)为EDTA酸根,Z~(5-)为DTPA酸根)。借助配离子MgY~(2-)和MgZ~(3-)的生成热文献数据,求得了RE~(3+)—Y~(4-)和RE~(3+)—Z~(5-)的配位热△H,并进一步计算出配离子REY~-和REZ~(2-)的其他生成热力学参数△G和△S。利用内插法粗略地估算了Tb、Er、Tm、Lu四元素相应的热力学量。     

VULCANIZATION KINETICS OF SILICONE RUBBER

Vulcanization rate of silicone rubber with the aid of organic peroxide or hydrosilylation agent was studied by using oscillation disk rheometer. It was found that the process of network formation would take place through one, two or three steps depending on the structure of the reactants. The effect of phenyl group, vinyl terminals on polysiloxane chain and the functionality of silylation agent was also studied.     

若干稀土Y分子筛催化剂的酸性与活性、积碳关系的初步研究

为了探讨什么样的酸中心是裂解活性中心,本文以四种稀土Y分子筛裂解催化剂和其它固体酸为对象,研究了表面酸性与裂解活性、积碳的关系。     

POLYMERIZATION OF ACRYLONITRILE WITH ORGANOLANTHANIDES AS SINGLE-COMPONENT CATALYSTS

 Ind₂Y(μ-Et)₂AlEt₂ and Ind₂LnN(i-Pr)₂ (Ln = Y, Yb) were used as a single-component catalyst for the polymerization of acrylonitrile (AN) respectively. The regularity of polymerization of AN and stereoregularity of polyacrylonitrile (PAN) were also studied in both cases. Both catalysts can produce PAN with molecular weight from I0,000to 30,000. In addition, the catalytic activity and molecular weights were increased by the addition of PhONa.