改性紫外光固化聚硅氧烷的合成及其感光性能

改性紫外光固化聚硅氧烷的合成及其感光性能;紫外光固化;聚硅氧烷;光敏性能     

聚氨酯改性不饱和聚酯/色浆复合体系的固化特性

系统研究了聚氨酯改性不饱和聚酯/色浆复合体系的黏度与固化特性,发现随着色浆含量的增加,复合体系的黏度呈递增趋势,但明显低于理论加和值;而复合体系的凝胶时间、表观起始固化温度与表观峰值固化温度随着色浆含量的增加而增加,但表观终止固化温度与固化热焓却降低;随着升温速率的增大,复合体系的特征固化温度均向高温方向移动,但固化热焓基本不变.将升温速率外推至零,可计算出体系的起始固化温度、峰值固化温度以及终止固化温度,从而确定体系的固化工艺.同时基于不同升温速率下的表观峰值固化温度,通过Kissinger方程可计算得到聚氨酯改性不饱和聚酯/色浆复合体系的固化反应表观活化能以及固化反应动力学指前因子.在最佳固化工艺条件下,聚氨酯改性不饱和聚酯树脂/色浆复合涂层的黏附力均在一级以上.     

松香改性不饱和聚酯合成的研究

本文提出了松香改性不饱和聚酯的最佳合成工艺条件以及制备了某些模型化合物,并用IR、UV、NMR、MS等方法分析鉴定。松香酸中的羧基与不饱和聚酯中的羟基反应生成酯,使聚酯端基失去活性不能再进一步反应;另一方面,Diels-Alder加成物产生支链,降低了结晶倾向。改性不饱和聚酯与苯乙烯能相互混溶,固化制品具有良好的抗水性与耐药品腐蚀性。     

改性聚乙二醇修饰高交联度不饱和聚酯网络结构的动态力学分析

合成了一系列含有反应活性端基的改性聚乙二醇,并用其对BMC(团状模塑料)专用的高交联度不饱和聚酯进行增韧.结果表明,含有反应性马来酸酐端基的聚乙二醇参与了不饱和聚酯的固化反应,可在交联网络中构成不同长度的柔性链段,在显著提高不饱和聚酯的韧性的同时,基本保持了材料的模量及其它力学性能.用动态力学分析(DMA)对不饱和聚酯交联网络结构进行了系统研究.     

不饱和聚酯/环氧树脂嵌段共聚树脂的光固化研究

光固化涂料以其节省能源、减少空气污染、固化速度快、适用于自动化流水线涂布等特点而引起涂料行业的关注 .随着世界范围内对环境保护的日益重视和绿色科技的蓬勃发展 ,光固化技术因其能有效地控制空气污染 ,特别是可以大大减少挥发性有机物的排放而越来越受到青睐[1] .不饱和聚酯树脂 (ＵＰＲ)型的光固化树脂是发展最早和销售量最大的光固化树脂 .它是由二元羧酸与多羟基醇共缩合的缩聚物与活性单体的混合产物 ,二元羧酸中含有部分不饱和成分 .主要用于光敏树脂印刷版、光敏油墨、光敏涂料及印刷电路版的光致抗蚀膜等 .但是感光不饱和聚酯…     

聚氨酯改性不饱和聚酯树脂的反应动力学

通过差示扫描量热法(DSC)和傅里叶红外光谱(FT-IR)分析,探讨了聚氨酯改性不饱和聚酯树脂(UPR)体系反应特征及固化反应动力学。结果表明:体系中聚氨酯网络的形成远快于UPR网络的形成。UPR和聚氨酯改性UPR体系的表观活化能分别为58.0 kJ/mol和64.8 kJ/mol,改性后体系的活化能并无较大变化;反应的级数分别为0.90和0.91。     

BMD/UP体系非等温固化动力学研究

不饱和聚酯是最常用的一种热固性材料,其力学性能和耐热性是较受关注的两个方面,利用双马来酰亚胺作为第二组分对不饱和聚酯进行耐热改性的工作取得了较好的效果。研究其动力学过程对于固化反应温度、时间等工艺合理优化控制,制备高性能复合材料具有重要意义。考虑到BMD／UP体系中反应的复杂性,本文采用n级动力学模型,进行了非等温动力学研究。     

不饱和聚酯/有机蒙脱土复合材料的固化动力学

用动态扭振法研究不饱和聚酯／有机蒙脱土复合材料的固化动力学行为。结果表明该实验体系能够很好地应用Flory理论和Avami方程进行拟合。用非平衡态热力学涨落理论对纳米复合材料的固化作了理论顸估,顸估结果与实验固化曲线有很好的相符性。有机蒙脱土的加入降低了不饱和聚酯的固化反应速率,对固化反应表现活化能和复合材料的形成过程没有很大的影响。根据实验结果分析不饱和聚酯在有机蒙脱土存在下的固化分为定型和熟化两个阶段,在一定的固化温度和填充含量下。从动态扭振曲线上可以明显地观察到这种“二次固化”现象。     

不饱和聚酯改性研究新进展

综述了不饱和聚酯改性的研究进展。介绍了不饱和聚酯增韧的方法,如液体橡胶、弹性体共混增韧、化学结构改性、纳米复合材料。不饱和聚酯收缩率控制研究,包括聚醋酸乙烯酯、聚苯乙烯、嵌段共聚和无机填料等低收缩添加剂的影响,及新型低收缩不饱和聚酯的合成。讨论了含磷阻燃剂和无卤阻燃剂对不饱和聚酯的影响。     

中国感光学会辐射固化专业委员会

正中国感光学会辐射固化专业委员会(下称专委会)成立于1993年9月,为了与国际辐射固化组织对应,对外称RadTech China。RadTech China也是亚洲辐射固化行业组织(RadTech Asia)的倡导者和重要成员之一,并为RadTech Asia主席或副主席单位。专委会是由全国辐射固化科技工作者和企业家自愿组成并依法登记的、公益性、学术与技术性、科普性的社会团体,是推动我国辐射固化产业发展的重要力量,是中国科学技术协会中国感光学会的组成部分,是中国共产党和政府联系广大辐射固化科技工作     

五种植物纤维粉填充不饱和聚酯树脂复合材料的性能对比

以芝麻秸秆粉、水稻秸秆粉、玉米芯秆粉、菠萝叶粉、甘蔗渣粉五种不同植物纤维粉为填充体、不饱和聚酯树脂(UPR)为基体制作植物纤维粉/UPR复合材料,对比研究了秸秆种类对复合材料密度、力学性能及吸水性能的影响。结果表明,植物纤维粉粒径为100目、添加量为UPR用量的10%时,芝麻秸秆粉/UPR复合材料的综合力学性能最好,拉伸强度、弯曲强度和冲击强度分别为41.320 MPa、67.467 MPa和2.815 KJ/m^2,且每一浸泡阶段吸水率均最低。     

Reactive rubbers as toughening agents for thermoset polyester resins. Molecular analysis by FTIR and fracture behavior of the resulting blends

A reactive rubber obtained by isocyanation of hydroxyl-terminated polybutadiene was used as toughening agent for an unsaturated polyester resin. Both the isocyanation and the successive reaction between the modified rubber and the polyester were investigated by Fourier-transform infrared spectroscopy (FTIR). Fracture measurements at high and low strain rate were carried out on the cured materials to test their toughness. The failure mechanisms were established by morphological analysis of fractured surfaces, performed by scanning electron microscopy. © 1993 John Wiley & Sons, Inc.     

CURE OF A MICROGEL-EPOXY RESIN TWO-PHASE POLYMER WITH ETHYLENE DIAMINE

The curing of a microgel-epoxy resin two phase polymer prepared by in situ copolymerization of unsaturated polyester with acrylic monomer was studied. The unsaturated unit reacted with N—H during the cure of the resin with ethylene diamine. The Michael type reaction was ten times more rapid than the addition of N—H to epoxide.This was accounted for the lower apparent activation energy of the curing of the two phase resin.     

Unsaturated polyester resins modified with phosphorus-containing groups: Effects on thermal properties and flammability

A novel reactive phosphorus-containing monomer [1-oxo-2,6,7-trioxa-1- phosphabicyclo-[2.2.2]octane-methyl diallyl phosphate, PDAP] was synthesized, and various amounts of PDAP were combined with unsaturated polyester by radical bulk polymerization. The resulting flame-retardant unsaturated polyester resin (FR-UPR) samples were investigated by thermogravimetric analysis (TGA), microscale combustion calorimetry (MCC), and limiting oxygen index (LOI) tests. Due to the relatively high phosphorus content of PDAP (18.2 wt%), incorporation of this monomer into unsaturated polyester resin (UPR) led to a marked decrease in the heat release capacity (HRC), the total heat release (THR), an increase in the LOI and the char yield upon combustion. In order to elaborate the interactions between the UPR and PDAP in degradation, differences between the experimental and theoretical mass losses of a FR-UPR sample were evaluated. Furthermore, thermogravimetry-Fourier transform infrared (TG-FTIR) and real-time Fourier transform infrared (RTIR) spectroscopy were employed to investigate the degradation behavior of UPRs, providing insight into the degradation mechanism.     

Critical aspects related to processing of carbon nanotube/unsaturated thermoset polyester nanocomposites

Carbon nanotubes (CNTs) have outstanding mechanical, thermal and electrical properties. As a result, particular interest has been recently given in exploiting these properties by incorporating carbon nanotubes into some form of matrix. Although unsaturated polyesters with styrene have widespread use in the industrial applications, surprisingly there is no study in the literature about CNT/thermoset polyester nanocomposite systems. In the present paper, we underline some important issues and limitations during the processing of unsaturated polyester resins with different types of carbon nanotubes. In that manner, 3-roll mill and sonication techniques were comparatively evaluated to process nanocomposites made of CNTs with and without amine (NH₂) functional groups and polyesters. It was found that styrene evaporation from the polyester resin system was a critical issue for nanocomposite processing. Rheological behaviour of the suspensions containing CNTs and tensile strengths of their resulting nanocomposites were characterized. CNT/polyester suspensions exhibited a shear thinning behaviour, while polyester resin blends act as a Newtonian fluid. It was also found that nanotubes with amine functional groups have better tensile strength, as compared to those with untreated CNTs. Transmission electron microscopy (TEM) was also employed to reveal the degree of dispersion of CNTs in the matrix.     

Adsorption of uranium ions by crosslinked polyester resin functionalized with acrylic acid from aqueous solutions

In this paper, the crosslinked polyester resin containing acrylic acid functional groups was used for the adsorption of uranium ions from aqueous solutions. For this purpose, the crosslinked polyester resin of unsaturated polyester in styrene monomer (Polipol 353, Poliya) and acrylic acid as weight percentage at 80 and 20%, respectively was synthesized by using methyl ethyl ketone peroxide (MEK_p, Butanox M60, Azo Nobel)-cobalt octoate initiator system. The adsorption of uranium ions on the sample (0.05 g copolymer and 5 mL of U(VI) solution were mixed) of the crosslinked polyester resin functionalized with acrylic acid was carried out in a batch reactor. The effects of adsorption parameters of the contact time, temperature, pH of solution and initial uranium(VI) concentration for U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid were investigated. The adsorption data obtained from experimental results depending on the initial U(VI) concentration were analyzed by the Freundlich, Langmuir and Dubinin–Radushkevich (D–R) adsorption isotherms. The adsorption capacity and free energy change were determined by using D–R isotherm. The obtained experimental adsorption data depending on temperature were evaluated to calculate the thermodynamic parameters of enthalpy (ΔH°), entropy (ΔS°) and free energy change (ΔG°) for the U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid from aqueous solutions. The obtained adsorption data depending on contact time were analyzed by using adsorption models such as the modified Freundlich, Elovich, pseudo-first order and pseudo-second-order kinetic models.     

高岭土对不饱和聚酯树脂的热稳定性、阻燃及力学性能的影响

不饱和聚酯树脂;高岭土;纳米复合材料;原位聚合;阻燃;成炭     

Synthesis,characterization, biocompatibility,thermal and mechanical performances of sawdust reinforced composite

The work outlines the synthesis of a new and easy technique to develop sustainable composites of sawdusts reinforced polyester resin composites. For shaping a new approach we have found very rare approach for developing composites with sawdusts of Mahagoni wood (Swietenia mahagoni) reinforced polyester resin composites in open literatures. Due to this gap, a plan made to develop untreated and treated sawdusts (very common in Bangladesh and many other countries of the world) reinforced strong and durable composites with unsaturated polyester resins along with their biodegradability, thermal and mechnical properties where the material properties were revealed and corelations were elaborated in the subsequent sections. Specifically, the tensile strengths of virgin resin (VR), untreated sawdust reinforced composite (UTSDC) and 4% caustic soda treated sawdust reinforced composite (4TSDC) are 10.77, 15.83 and 21.64 N/mm², respectively. That means the observed reinforcement property for UTSDC and 4TSDC increased ~47% and 101%, respectively. Moreover, the binding phenomena were explained with the own schamatic presentation. The composite phenomena was explained sequentially by using Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, etc. Between the developed composites 4TSDC was strong (25% as compared from tensile strength) and durable (8% as observed in biodegradability results) than the UTSDC of unsaturated polyester resin. The pattern of water uptake follows usual Fickian diffusion behavior. The observed properties of the developed convincible composites indicate that they can be considered for indoor to outdoor applications especially for using the fence, roof, furniture items like chair, table, park benches, etc.