Thermal cure monitoring of phenolic resole resins based on in situ fluorescence technique

The thermal curing reaction of two phenolic resole resins is monitored using the fluorescence technique. The intrinsic fluorescence can be used as an indicator for cure monitoring for the first resole. As the thermal curing proceeds, the intrinsic fluorescence intensity of the resole resin decreases and exhibits a few nanometers of redshift. The fluorescence intensity of the emission maxima is correlated with the conversion measured by differential scanning spectroscopy. A linear correlation is found at three different temperatures. The intrinsic fluorescence cannot always be used for monitoring the curing process of phenolic resole resins. Thus, three intramolecular charge transfer compounds and two organic donor–π‐acceptor salts are selected and applied for the cure monitoring of the second phenolic resole resin. As the curing reaction proceeds, the fluorescence emission spectra of the probes exhibit a blue spectral shift and the intensity changes because of environmental changes. An intensity ratio method is applied in which the ratios of the low‐ to high‐intensity changes in the emission bands are used to determine the degree of the curing process. There is a smooth correlation between the intensity ratio method and the degree of cure. The method enables one to follow the changes in the polymer structure at low and intermediate degrees of the curing process (below 70%) and obtain comparable results from different types of probes during the same curing process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1773–1780, 2002     

单组分湿固化聚氨酯密封剂的制备、固化特性及开发应用

介绍了单组分湿固化聚氨酯密封剂的制备、固化特性及该产品的国内外发展概况，并就其开发工作提出了看法。     

低分子1,2-聚丁二烯对HNBR过氧化物硫化的影响

研究了助交联剂液体乙烯基聚丁二烯对氢化丁腈橡胶(HNBR)硫化过程和物理机械性能的影响，结果表明：当其用量为4份时，弹性扭矩最大，拉伸强度24．8MPa，拉断伸长率334％，分别比空白样提高13％和50％；表观交联密度适宜，压缩永久变形29％低于空白样的44％，6份时的47％和8份时的55％；热空气老化后仍保持较高的强伸性能。     

Influence of ZnO nanoparticles on the cure characteristics and mechanical properties of carboxylated nitrile rubber

Zinc oxide (ZnO) nanoparticles assembled in one dimension to give rod‐shaped morphology were synthesized. The effect of these ZnO nanoparticles (average particle size ～ 50 nm) as the curing agent for carboxylated nitrile rubber was studied with special attention to cure characteristics, mechanical properties, dynamic mechanical properties, and swelling. These results were compared with those of the conventional rubber grade ZnO. The study confirmed that the ZnO nanoparticles gave a better state of cure and higher maximum torque with a marginal decrease in optimum cure time and scorch time. The mechanical properties also showed an improvement. There was an increase in tensile strength by ～ 120%, elongation at break by ～ 20%, and modulus at 300% elongation by ～ 30% for the vulcanizate cured with ZnO nanoparticles, as compared with the one containing rubber grade ZnO. Dynamic mechanical analysis revealed that the vulcanizates exhibited two transitions—one occurring at lower temperature due to the T_g of the polymer, while the second at higher temperature corresponding to the hard phase arising due to the ionic structures. The second transition showed a peak broadening because of an increase in the points of interaction of ZnO nanoparticles with the matrix. The tan δ peak showed a shift towards higher T_g in the case of ZnO nanoparticle‐cured vulcanizate, indicating higher crosslinking density. This was further confirmed by volume fraction of rubber in the swollen gel and infrared spectroscopic studies. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

室温固化型不粘涂料的研究

研究了双组分室温固化型低表面能氟涂层的配合技术,所用材料的物化特性;讨论了基料、填料、助剂等对氟涂料的影响机理。实验结果表明:氟涂层的表面能为10.6 mJ/m2,疏水角可达到122°,附着力为1级、硬度为4H,同时涂层具有耐腐蚀和耐化学性等性质。     

不饱和酸结构对不饱和聚酯树脂固化行为的影响

通过IR分析了用顺酐和反酸与聚酯合成不饱和聚酯树脂的反应机理,讨论了二种树脂体系固化放热曲线不同的原因。     

用于光纤并带的UV固化胶粘剂性能的研究

研究了用于光纤带的紫外光固化胶粘剂的剥离性、柔韧性、拉伸强度和延伸率的影响因素。     

低温固化双马来酰亚胶树脂基体研究──引发剂的作用

本文以典型的ＸＵ２９２双马体系作为研究对象，选用引发剂加速树脂的固化反应，以期得到低温固化耐热的双马树脂体系。研究结果表明，引发剂能很有效地降低双马树脂的固化温度，低温固化阶段比高温固化阶段对树脂耐热性的影响更大。经１２０℃／８ｈ＋１４０℃／２ｈ＋１６０℃／２ｈ固化树脂的热变形温度为２６６℃，再经１８０℃／８ｈ的后处理，热变形温度达到３００℃。     

二乙烯基硅氧烷-双苯并环丁烯树脂的制备与性能研究

苯并环丁烯树脂在许多高科技领域都有应用,是当今高性能树脂研究的热点之一.本文采用Heck反应合成了二乙烯基硅氧烷-双苯并环丁烯树脂,并用红外、质谱、核磁共振对其结构进行了表征,研究了该树脂的固化反应,最后测定了固化树脂的物理性能.研究结果表明,二乙烯基硅氧烷-双苯并环丁烯固化树脂具有优异的热稳定性能和介电性能.     

《SOHO网络组建与管理》分级制课程设计

职业教育分级是现代化建设对于技能型人才需要的层次性、专业性、发展性。职业教育分级标准反映的是社会分工的复杂性和用人结构的层次性对职业人才应当具备的职业素养、技能水平和文化知识的具体要求。在该教育改革的指引下,作者在《SOHO网络组建与管理》课程的教学中,根据职业岗位的要求来重新整合教学资源,以项目为依托,以任务驱动为导向,运用一体化的模式进行课程教学设计。