室温固化高温使用环氧树脂胶粘剂的研究进展

介绍了室温固化高温使用环氧树脂(EP)胶粘剂的特点,简述了EP胶粘剂的研究现状、存在的难点和发展趋势。     

Extending onshore pipeline repair to offshore steel risers with carbon–fiber reinforced composites

In the last 15 years, glass fiber hoop reinforced composite systems emerged as an acceptable, successful method for repairing corroded and mechanically-damaged onshore pipelines where the primary load is internal pressure. The feasibility of extending these repairs to offshore pipes such as risers require a thorough understanding of the complex combined load profiles; overlay of significant tension, bending, internal and external pressure. Herein an innovative design based on integrated computational models and full-scale tests is presented to address the viability of reinstating capacity to offshore pipelines and risers. The experimental program was based on a collaborative test matrix developed with the participation of composite repair manufacturers. The outcome guided and led to an easily deployable carbon–fiber composite repair system which was based on limit analysis methods and strain-based design techniques. It is anticipated that the results of this program will foster future investigations by integrating operator’s insight and in situ data gathering to extend composite repair for offshore needs.     

Effects of chemical oxidations on the fracture toughness of leadframe/EMC interfaces

Cu-based leadframe sheets were oxidized by a chemical oxidation method, which formed two kinds of oxides on its surface, a brown one and a black one. The oxidation characteristics of each oxide were studied and then to measure the adhesion strength of the leadframe/EMC interface as a function of fracture toughness, the oxidized leadframe samples were molded with an epoxy molding compound (EMC) and machined to form sandwiched double-cantilever beam (SDCB) specimens. SEM and XRD studies on the surfaces of the oxidized leadframe as well as the measurement of fracture toughness showed that the interfacial fracture toughness is directly related to the formation of acicular CuO precipitates on the surface of the leadframe. However, once a continuous layer of CuO precipitates formed on the surface of the leadframe (brown oxide) or on the Cu₂O layer (black oxide), the interfacial fracture toughness is found to saturate regardless of a further oxide thickening. The size of the acicular precipitates seems to have a secondary effect on the interfacial fracture toughness.     

苯丙乳液改性砂浆的微观结构与性能(英文)

用2种具有不同性质的苯丙乳液来研究聚合物对砂浆各种性能的影响,测量了不同聚合物掺量下,聚合物改性砂浆的流动性及力学性能.通过测量砂浆凝结硬化过程中绝热温升来研究聚合物对砂浆中水泥水化过程的影响.用扫描电子显微镜观察了聚合物改性砂浆的微观结构.结果表明:由于聚合物成膜及其与水泥水化产物的相互作用.砂浆的力学性能得到显著改善.聚合物的性质不同,对砂浆性能的影响作用不同.环境扫描电子显微镜对新拌水泥浆的原位观察证实了乳液聚合物粒子在水泥颗粒上的迅速吸附,为解释聚合物对新拌砂浆流动性能的改善以及对水泥水化的延滞作用提供了直接证据.     

Anionic alternating copolymerization of epoxide and 3,4‐dihydrocoumarin and its application to networked polymers

3,4‐Dihydrocoumarin (DHCM) is an aromatic six‐membered lactone, which does not undergo anionic homopolymerization. However, it does undergo copolymerization with an epoxide. The striking feature of this copolymerization is its 1:1 alternating nature, which allows for the formation of polyesters. In this mini‐review, we describe the copolymerization behavior, the polymer structure and the advantages that can be achieved by addition of DHCM to the epoxy‐imidazole curing system. Another focus is our development of DHCM analogues, which bring the advantages of DHCM to their applications as comonomers for the curing system. Copyright © 2009 Society of Chemical Industry     

环氧树脂改性PUA乳液的合成及性能研究

以异佛尔酮二异氰酸酯（IPDI）、聚醚二元醇（N220）、二羟甲基丙酸（DMPA）、1，4-丁二醇（BDO）和甲基丙烯酸甲酯（MMA）为主要原料合成了脂肪族聚氨酯-丙烯酸酯复合乳液（PUA），并用环氧树脂对其进行了改性。研究了nNCO／nOH比、DMPA添加量、环氧添加方式及添加量对其性能的影响，结果表明，当nNCO／nOH为1．35-1．4、DMPA为6％～7％时，以环氧和BDO一起加入，环氧添加量在2％～3％时能获得综合性能较好且贮存稳定的聚氨酯丙烯酸酯复合乳液。     

聚硅氧烷改性环氧树脂体系的制备,形态与性能

聚胡氧烷－环氧树脂体系微相分离形态形成过程不同于一般反应性液体橡胶改性环氧树脂。此体系微相分离结构是在预反应过程中形成的，是聚硅氧烷在环氧树脂中的分散和聚结两种趋势共同作用的结果。预反应中形成的嵌段共聚物使该体系微相分散微细而且均匀，一未改性环氧树脂相比，经预反应制得的固化物弯曲杨氏模量和玻璃态线性热膨胀系数均有明显下降，因此内应力大幅度降低，抗开理解指数大为提高；而直接共混法改性环氧树脂低应力化     

环氧煤沥青涂层防腐蚀失效的原因分析与改进措施

环氧煤沥青涂料是埋地管道外防腐常用的涂料之一,文章列举了环氧煤沥青涂层防腐失效的几种表现,针对环氧煤沥青涂层在实际应用中出现的失效情况,从材料质量、施工过程控制和运输安装过程3个方面进行了分析,并提出了提高环氧煤沥青涂层防腐效果的几点措施和建议。     

聚氨酯柔性固化剂的合成及增韧环氧树脂的研究

运用分子设计的方法合成出了端胺基聚氨酯(ATPU)结构的聚氨酯柔性固化剂,用FT-IR表征了ATPU的分子结构,通过DSC和TG等表征了ATPU/EP固化过程的特性及固化产物的性能。结果表明,红外光谱分析证实了ATPU的结构符合分子设计要求;ATPU/EP固化体系相对于未改性的乙二胺/EP固化体系,其柔韧性和抗冲击性都有很大提高;ATPU/EP固化物在热分解后期表现出更好的热稳定性。     

年产120吨聚丙烯酸钠絮凝剂的工艺设计与投产

介绍了新开发的生产工艺过程及工艺条件，对120吨/年的工厂设备选型、工厂经济分析及其应用效果作了简要评述。