降解型环氧树脂*

设计与合成带有可降解官能团的环氧树脂是热固性树脂回收领域的一个重要课题。本文首先简要概括了传统回收环氧树脂的方法并指出其缺点,然后分别对国内外热降解型、光降解型、生物降解型环氧树脂的降解特性、环氧固化物的降解条件和降解机理予以重点解释和举例介绍。最后,指出了降解型环氧树脂存在的问题并对将来的发展前景进行了展望。     

Hyperbranched Acrylated Aromatic Polyester Used as a Modifier in UV-Curable Epoxy Acrylate Resins

The viscosity,the shrinkage degree and the photopolymerization rate of the epolxy acrylate(EB600) blended with hyperbranched acrylated aromatic polyester(HAAPE) were investigated.The addition of HAAPE into EB600 largely reduces the viscosity of the blend formulation and the shrinkage degree.For example,EB600 resin with 50% weight fraction of HAAPE has the 1250 cps of the viscosity and 2.0% of shrinkage degree,while the pure EB600 resin has 3000 cps of the viscosity and 10.5% of shrinkage degree.The photopolymerization rate of the resin is also promoted by HAAPE addition.The good miscibility between HAAPE and EB600 was also observed from the dynamic mechanical analysis.The tesile,flexural and compressive strength,and the thermal properties of the UV cured films are greatly improved.     

A Comparison of the Syntheses of High Molar Mass Epoxy Resins on the Basis of two Groups of Modified Vegetable Oils

Application of epoxidized and hydroxylated natural oils as a new group of environmentally friendly and renewable raw materials for the synthesis of high molar mass epoxy resins is described. Selected vegetable oils were first oxidized and next reacted with mono and diethylene glycols. Obtained epoxidized soybean, rapeseed, linseed and sunflower oils were used together with Bisphenol A in the fusion process. Analogously, hydroxylated soybean and rapeseed oils were reacted with commercial grade Bisphenol A-based low molar mass epoxy resin. The fusion process was carried out in the presence of selected catalysts (i.e., lithium chloride, 2-methylimidazole, triphenylphosphine and triethanolamine) giving high molar mass epoxies. The relationship between type of modified oil used in the synthesis and reaction conditions and properties of synthesized resins (e.g., value and distribution of average molar mass, contents of epoxy groups and colour) is discussed.     

Improving the Antimicrobial and Mechanical Properties of Epoxy Resins via Nanomodification: An Overview

The main purpose of this work is to provide a comprehensive overview on the preparation of multifunctional epoxies, with improved antimicrobial activity and enhanced mechanical properties through nanomodification. In the first section, we focus on the approaches to achieve antimicrobial activity, as well as on the methods used to evaluate their efficacy against bacteria and fungi. Relevant application examples are also discussed, with particular reference to antifouling and anticorrosion coatings for marine environments, dental applications, antimicrobial fibers and fabrics, and others. Subsequently, we discuss the mechanical behaviors of nanomodified epoxies with improved antimicrobial properties, analyzing the typical damage mechanisms leading to the significant toughening effect of nanomodification. Some examples of mechanical properties of nanomodified polymers are provided. Eventually, the possibility of achieving, at the same time, antimicrobial and mechanical improvement capabilities by nanomodification with nanoclay is discussed, with reference to both nanomodified epoxies and glass/epoxy composite laminates. According to the literature, a nanomodified epoxy can successfully exhibit antibacterial properties, while increasing its fracture toughness, even though its tensile strength may decrease. As for laminates—obtaining antibacterial properties is not followed by improved interlaminar properties.     

含环氧基的丙烯酸酯共聚物改性环氧树脂

合成了一系列含环氧基团的丙烯酸酯聚合物（ＨＧＭＢ），并对其改性环氧树脂／４，４‘－二氨基二苯基甲烷的抗冲性能，动态力学行为进行了考察，结果表明：当必性体系中加入质量分数为１５％的ＨＧＭＢ（甲基丙烯酸缩水甘油酯、甲基丙烯酸羟乙基酯、甲基丙烯酸甲酯、丙烯酸丁酯的摩尔分数分别为４．３％、５％、２５．７％、６５％）时，与空白体系相比，改性体系的冲击强度提高５０％，且玻璃化有所提高，模量没有降低。     

Mechanical and Thermal Properties and Morphology of Epoxy Resins Modified by a Silicon Compound

A silicon compound (GAPSO) was synthesized to modify the diglycidyl ether of bisphenol-A (DGEBA). The chemical structure of GAPSO was confirmed using FT-IR, ²⁹Si NMR and GPC. The mechanical and thermal properties and morphologies of the cured epoxy resins were investigated by impact testing, tensile testing, differential scanning calorimetry and environmental scanning electron microscopy. The impact strength and tensile strength were both increased by introducing GAPSO, meanwhile the glass transition temperature (T_g ) was not decreased and the morphologies of the fracture surfaces show that the compatibility of GAPSO with epoxy resin was very good and the toughening follows the pinning and crack tip bifurcation mechanism. The high functional groups in GAPSO can react during the curing process, and chemically participate in the crosslinking network. GAPSO is thus expected to improve the toughness of epoxy resin, meanwhile maintain the glass transition temperature.     

高折射率环氧和环硫型光学树脂的研究进展

环氧树脂;环硫化合物;高折射率环氧和环硫型光学树脂的研究进展     

固化剂对双介晶基元液晶环氧树脂相结构和热性能的影响

以芳香二胺（SAA）、酸酐（THPA）和叔胺（DMAP）为固化剂,固化偶氮类双介晶基元液晶环氧树脂,采用偏光显微镜和X射线衍射研究了固化剂对液晶热固体相结构产生的影响。DMAP催化环氧自聚固化,有利于液晶分子的有序排列,易于形成梯形结构,可以得到近晶相的固化产物。SAA在较低温度下固化时也得到近晶相结构,但在较高温度固...     

Spectroscopic,Mechanical and Dynamic-Mechanical Studies on the Photo-Aging of a Tetrafunctional Epoxy Resin

The photo-oxidative degradation of a densely cross-linked epoxide/diamine network based on tetraglycidyl-4,4′ diaminodiphenylmethane (TGDDM) and 4,4′ diaminodiphenyl sulphone (DDS) has been investigated by FTIR spectroscopy, dynamic-mechanical analysis (DMA) and compressive mechanical tests. The FTIR measurements allowed us to monitor the degradation process of the different groups present in the TGDDM/DDS network and to obtain reliable kinetic data. On this basis the most likely photo-degradation mechanisms were proposed. Dynamic-mechanical measurements and mechanical compressive tests were used to gain an insight in the effect of the photo-oxidative degradation on the relaxation processes of the epoxy network and on the mechanical performances.     

Effect of Hyperbranched Polyester on Modification of Epoxy Resins Cured with Anhydride

Epoxy resins are widely used in coatings, adhesives and polymer composites, but the applications of cured epoxy resins are often restricted by their poor toughness. HBP can be used as toughener to improve the toughness of epoxy resins due to its high-dens…     

高性能脂环族环氧树脂分子设计与合成研究进展

脂环族环氧树脂具有优异的加工性、热稳定性、电绝缘性和耐紫外辐射等综合性能,已经广泛应用于航空航天、微电子封装和电机绝缘等重要工业领域。针对现代工业对高分子材料日益提高的性能和功能化要求,近年来脂环族环氧树脂的合成与性能研究非常活跃。本文综述了新型脂环族环氧树脂的分子设计与合成进展,包括环氧官能度、交联密度和玻璃化温度可...     

松香改性酚醛环氧树脂的合成与表征

以松香,环氧氯丙烷,甲醛及苯酚等为主要原料,合成了一种新型的环氧树脂。通过正交实验法确定了环氧化反应的最佳实验条件,即环氧化温度90℃,碱用量13 g,催化剂为cat 1,其最佳用量为0.018 mol,环氧氯丙烷的用量为50 g,碱浓度为30%(以上数值均以松香用量为70 g时计)。在最佳实验条件下合成得到了松香改性酚醛环氧树脂(简称RAPE),并用HPLC、FT-IR、NMR对其进行结构表征。结果表明,得到的RAPE其环氧值为0.28 mol/100g,平均聚合度约为3.4,酚羟基和树脂酸上的羧基基本反应完全,得到一种新型的缩水甘油醚型和缩水甘油酯型的环氧树脂。     

聚醚接枝聚硅氧烷共聚物改进环氧树脂表面性能的研究

共混改性;形态;聚醚接枝聚硅氧烷共聚物改进环氧树脂表面性能的研究     

Waste Cooking Oil-Modified Epoxy Asphalt Rubber Binders with Improved Compatibility and Extended Allowable Construction Time

The application of crumb rubber from end-of-life tires and waste cooking oil (WCO) in road pavements is of significant importance from an economic and environmental viewpoint. However, the incorporation of crumb rubber greatly shortens the allowable construction time of epoxy asphalt binders due to the high viscosity of the epoxy asphalt rubber (EAR) binder and poor compatibility between crumb rubber and asphalt binder. To lower the viscosity of asphalt rubber, extend the allowable construction time and improve the compatibility of EAR binder, waste cooking oil (WCO) was introduced. The effect of WCO on the viscosity–time behavior, thermal stability, dynamic modulus, glass transitions, crosslink density, damping ability, compatibility, mechanical properties and phase separation of WCO-modified EAR binders was investigated by using the Brookfield viscometer, thermogravimetric analysis, dynamic mechanical analysis, universal testing machine and laser confocal microscopy. The test results demonstrated that the incorporation of WCO declined the viscosity and extended the allowable construction time of the unmodified EAR binder. The inclusion of WCO improved the compatibility between asphalt and crumb rubber and the damping ability and elongation at the break of the unmodified EAR binder. The presence of WCO had a marginal effect on the thermal stability of the unmodified EAR binder. Confocal microscopy observation revealed that asphalt rubber particles aggregated in the epoxy phase of the unmodified EAR binder. With the inclusion of WCO, co-continuous asphalt rubber particles became more spherical.     

Studies on the Cure Reaction and Relationship between Network Structure/Thermal Properties of Styrene Copolymers Based on Adypic/Sebacic Acid Modified Unsaturated (Epoxy) Polyesters

The studies on the relationship between network structure/thermal properties of styrene copolymers based on adypic/sebacic acid modified unsaturated (epoxy) polyesters cured using different hardeners as well as the course of the cure reaction of polyesters with styrene have been presented. The adypic/sebacic acid modified unsaturated polyesters (UP) prepared from 4-cyclohexene-1,2-dicarboxylic anhydride (THPA), maleic anhydride (MA), adypic acid (AA) or sebacic acid (SA) and ethylene glycol (EG) and their epoxy derivatives: adypic/sebacic acid modified unsaturated epoxy polyesters (UEP) were subjected to the cure process with styrene using diacyl peroxide: benzoyl peroxide (BPO) or the mixture of BPO/suitable acid anhydride: 4-cyclohexene-1,2-dicarboxylic anhydride (THPA) or glutaric anhydride (GA). Thermal properties were evaluated by means of DSC, TG and DMA analyses. It was proved that studied properties were significantly depended on polyester's structure and the type of applied curing system. Generally, higher values of E'_20°C, tgδ_max, E”, ν_e, IDT, T_k for styrene copolymers based on UEP were obtained. It was connected with more cross-linked polymer network structure due to the possible copolymerization reaction of carbon-carbon double bonds of polyester with styrene and additional polyaddition of epoxy to anhydride groups or thermal curing of epoxy groups. The additional connections between polyester's chains led to obtain more stiff and thermal stable polymeric materials. Moreover, the increase of saturated aliphatic acid's chain length in polyester backbone caused the decrease of E'_20°C, tgδ_max, E”, ν_e, IDT, T_k values of styrene copolymers. It suggested that copolymers based on polyesters prepared from acid containing more methylene groups in their structure were characterized by more flexible polymer network due to the “laxity” effect of aliphatic chains.     

Dynamic mechanical properties of epoxy‐phenolic mixtures

The dynamic‐mechanical properties of different mixtures formed by an epoxy resin (DGEBA type) and a phenolic resin (resole type) cured by trietylenetetramine and/or p‐toluensulphonic acid at different concentrations have been studied by means of dynamic mechanical thermal analysis (DMTA). All samples were cured by pressing at 90 °C during 6 h. The mechanical studies were performed between ?100 to 300 °C at a heating rate of 2 °C/min. This study was also carried out for the epoxy‐TETA and phenolic‐p‐toluensulphonic acid systems. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1548–1555, 2005     

Curing and Glass Transition of Epoxy Resins from Ester-Carboxylic Acid Derivatives of Mono- and Disaccharides,and Alcoholysis Lignin

Mono- and disaccharides (SAC) such as glucose (Glc), fructose (Frc) and sucrose (Suc), and also alcoholysis lignin (AL) were dissolved in ethylene glycol and each of the obtained mixtures was reacted with succinic anhydride to form a mixture of ester-carboxylic acid derivatives such as SAC-polyacid, SACPA, and AL-polyacid, ALPA. Ethylene glycol-polyacid (EGPA) was also prepared from ethylene glycol. Each of the obtained mixtures of ester carboxylic acid derivatives was reacted with ethylene glycol diglycidyl ether in the presence of a catalytic amount of dimethylbenzylamine to form ester-epoxy resins. The molar ratios of epoxy groups to carboxylic acid groups ([EPOXY]/[ACID] ratios, mol mol⁻¹) was maintained at 1.0. The contents of SACPA and ALPA in the mixtures of SACPA/EGPA, and ALPA/EGPA, respectively, were also varied from 0 to 100 %. The curing reaction of SucPA and ALPA was studied by differential scanning calorimetry (DSC). Activation energy of the curing reaction for the SucPA system was 80.5 kJ/mol. Thermal properties of epoxy resins were studied by DSC. Glass transition temperatures (T_g) decreased with increasing numbers of repeating units in ester chains between cross-linking points, suggesting that ester chain lengths between cross-linking points mainly affect the mobility of ester chains in epoxy resin networks.