吸波性PMI泡沫塑料的制备及性能研究

通过增粘和分散技术将吸波剂导电碳黑引入到聚甲基丙烯酰亚胺(PMI)泡沫塑料中,制备出了具有一定吸波性能的PMI泡沫塑料。实验发现,采用高速剪切和高功率超声波的复合分散法可将吸波剂导电碳黑均匀分散至增粘后的单体混合液中,且增粘剂和吸波剂对聚合与发泡过程无不良影响。结果表明,随着导电碳黑用量增加以及试样厚度的增加,PMI泡沫塑料的吸波性能显著提高。由于采用了增粘树脂,同密度吸波性PMI泡沫塑料的压缩性能下降。     

定型剂对单轴向经编织物复合材料力学性能影响的试验研究

研究了真空辅助树脂注射（VARI）工艺中定型剂对环氧树脂的影响及其在织物表面的分布形式,以及定型剂用量对单轴向经编织物复合材料力学性能的影响,以确定最优的定型参数。采用示差扫描量热法（DSC）和扫描电镜（SEM）分别对加入不同用量定型剂的环氧树脂的玻璃化转变温度和相形貌进行分析,并测试了加入不同用量定型剂后复合材料的力学性能。结果表明：随着定型剂用量的增加,环氧树脂的玻璃化转变温度逐渐降低,且其相形貌逐渐由海岛结构经过双连续相结构到最后的相反转结构;室温下,随着定型剂用量的增加,织物表面定型剂的厚度及不均匀性增加,经过高温处理后,定型剂均匀分布在织物表面。定型剂用量对单轴向经编织物复合材料力学性能有较大影响,用量为20 g/m²时,复合材料体系的综合力学性能最优。     

Miscibility and PSA Performance of Acrylic Copolymer and Tackifier Resin Systems

The influence of miscibility of an acrylic PSA and several tackifier resin systems upon PSA performance was investigated. When the acrylic copolymer and the resins were blended in various proportions, three types of mixing state were found: miscible system, partially miscible system and immiscible system. In the case of miscible systems, PSA performance (tack, peel strength and shear resistance) depended upon the viscoelastic properties of the PSA. In the case of completely immiscible systems, the above PSA performance depended primarily upon the viscoelastic properties of a continuous matrix phase, and the separated resin phase acted as a kind of filler. In the case of partially miscible systems, the PSA performance changed discontinuously at the resin concentration where phase separation occurred. It suggests that the phase structure of a PSA greatly influences the PSA's performance.     

Miscibility Between Ethylene Vinyl Acetate Copolymers and Tackifier Resins

A series of ethylene vinyl acetate copolymer (EVA) were blended with various kinds of tackifiers and the miscibility between the components was investigated. The miscibility of the blend is illustrated as a phase diagram. The EVA and modified rosin systems tended to have a phase diagram with lower critical solution temperature (LCST), whereas the EVA and petroleum resin systems tended to have that with upper critical solution temperature (UCST). The phase diagrams of EVA/tackifier resins systematically changed as VAc content in the copolymer increased, which is accounted for by the classical Flory-Huggins theory.     

影响WBN增粘粒状铵油炸药性能的主要因素分析

在性能试验研究的基础上，根据工业炸药的混合反应机理，分析了影响WBN增粘粒状铵油炸药性能的主要因素。分析结果表明，柴油和敏化增粘剂含量是影响炸药爆轰感度的决定性因素；多孔粒状硝酸铵的含水量、吸油率、粒度、颗粒强度及炸药的混合度是影响产品性能和质量的主要因素；该种炸药适用于中小直径炮孔的爆破，其最佳装药密度为1．0—1．05g／cm^3。     

J-104石油管道固定片胶的研制

主要介绍以乙烯-丙烯酸乙酯共聚物为主体材料,适当加入增粘剂、填料和其它助剂,制成的一种新型胶粘剂。研究了它们的配比与性能的关系。并采用了辐射交联的技术方法,使这种胶粘剂对聚乙烯粘接性能更好。     

Comparison of the Effect of a Hydrocarbon Oil and a Terpene Tackifier on the Autohesion of Styrene-Butadiene Rubber

Blends of uncrosslinked styrene-butadiene rubber (SBR) with a terpene tackifier resin or a naphthenic oil have been characterized, and their autohesion and cohesion determined using a T-peel geometry. SBR/oil blends are homogeneous at all proportions, while SBR/resin blends, based on DSC and DMA analysis, undergo bulk phase separation at about 50% resin. However, migration of tackifier to the surface region is proposed at much lower resin contents. Compositions diluted with oil have autohesion similar to the neat SBR. This is attributed to compensating effects; although oil hastens self-bond formation by increasing chain mobility, this is nearly equally balanced by more facile chain separation during bond rupture. In short, oil-diluted compositions are soft and weak. On the other hand, SBR compositions containing small amounts of resin have high autohesion. Resin-diluted specimens deform easily at low strain, just as those containing oil, but intertwined chains of the former have greater resistance to separation, due at least in part to higher glass transition temperatures. It is proposed that autohesion is further enhanced by migration of tackifier to the surface. This causes SBR/resin compositions to be both soft and strong-a necessary condition for high autohesion.     

Miscibility and Probe Tack of Acrylic Pressure Sensitive Adhesives—Acrylic Copolymer/Tackifier Resin Systems

Miscibility between acrylic copolymers and tackifier resins are investigated in terms of phase diagrams, and the probe tack of the blends are measured as a function of both temperature and rate of separation in order to obtain the master curves. It is found that the probe tack of the pressure sensitive adhesives are closely related to the miscibility between the components. The master curves of the miscible blends shift along the X(rate)-axis according to the change of T_g of the bulk materials with a gradual variation of the peak heights. However, those of the immiscible blends will not shift along the X(rate)-axis, but the magnitude will decrease with increase of a dispersed phase.     

J-104石油管道固定片胶的研制

主要介绍以乙烯-丙烯酸乙酯共聚物为主体材料,适当加入增粘剂、填料和其它助剂,制成的一种新型胶粘剂。研究了它们的配比与性能的关系。并采用了辐射交联的技术方法,使这种胶粘剂对聚乙烯粘接性能更好。     

PSA performances and viscoelastic properties of SIS‐based PSA blends with H‐DCPD tackifiers

Hotmelt pressure sensitive adhesives (PSAs) usually contain styrenic block copolymers like styrene–isoprene–styrene (SIS), SBS, SEBS, tackifier, oil, and additives. These block copolymers individually reveal no tack. Therefore, a tackifier is a low molecular weight material with high glass transition temperature (T_g), and imparts the tacky property to PSA. The SIS block copolymer with different diblocks was blended with hydrogenated dicyclopentadiene (H‐DCPD tackifier), which has three kinds of T_g. PSA performance was evaluated by probe tack, peel strength, and shear adhesion failure temperature. PSA is a viscoelastic material, so that its performance is significantly related to the viscoelastic properties of PSAs. We tested the viscoelastic properties by dynamic mechanical analysis and the thermal properties by differential scanning calorimeter to investigate the relation between viscoelastic properties and PSA performance. © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 2839–2846, 2006