三组份酚醛树脂冷压制备离合器摩擦材料

提出采用三组份改性酚醛树脂和混杂纤维冷压工艺制备离合器摩擦材料.三组份酚醛树脂为硼改性腰果壳油液体树脂、三聚氰胺改性酚醛液体树脂和芳烷基改性酚醛固体树脂.混杂纤维由玻璃纤维和复合包芯纱混杂构成.结果表明,采用三组份酚醛树脂和混杂纤维可以制备出摩擦性能良好,350℃不发生热衰退的离合器摩擦材料,且材料具有合适的孔隙率.     

碳纤维表面改性研究进展

碳纤维因其优异的综合性能常被用作树脂基体的增强材料.然而由于碳纤维与树脂基体之间的界面结合性能较差,其增强的复合材料的力学性能往往与理论值相差甚远,因此必须对碳纤维进行表面改性,以提高其与聚合物基体的界面粘结性能.本文作者综述了国内外关于碳纤维表面改性技术的研究进展,概述了涂层法、氧化法、高能辐射法等改性方法对碳纤维增强复合材料界面强度的改性效果.     

原位聚合法制备聚合物/纳米SiO_2复合材料的研究进展

纳米SiO_2改性聚合物制备的关键在于提高纳米粒子与聚合物基体的相容性及分散性;对纳米SiO_2进行不同的表面改性及选择合适的复合材料制备方法可以改变纳米粒子与聚合物基体的界面结合方式以及相容性和分散性,进而在不同程度上影响材料的性能.本文介绍了改性前后纳米SiO_2与聚合物基体的多种界面结合方式,对近年来利用原位聚合法制备聚合物/纳米SiO_2复合材料的研究现状和进展进行了综述.     

线性酚醛树脂在集成电路领域的应用与研究进展

在集成电路领域中,线性酚醛树脂作为基础树脂,是关键的功能材料。然而,传统的酚醛树脂存在稳定性差、感光速度慢、透明度、分辨率和机械强度低等问题,增加了应用成本和技术难度,降低了酚醛树脂在集成电路领域的经济效益。因此,需要对传统线性酚醛树脂进行改性以更好地应用于集成电路领域。本文综述了近年来线性酚醛树脂在芯片光刻胶、电子封装及覆铜板应用的研究现状,总结了目前改性线性酚醛树脂的主要方法,并展望了线性酚醛树脂的发展趋势,为未来高性能集成电路应用材料的研发提供参考。     

硼改性酚醛树脂的制备及其耐热性能研究

酚醛树脂因其材料成本低、工艺简单、原料易得等优点，在工业上得到了广泛应用。但由于其耐热性不足以及游离酚含量较高等因素，限制了其应用范围。本文利用硼酸对酚醛树脂进行改性，利用红外和质谱对其结构进行表征，改性后酚醛树脂的耐热性能、游离酚等指标得到明显改善。当失重20%时酚醛树脂改性前后耐热性能提高了56℃,可能是由于硼酚醛树脂中含有硼的三维交联网状结构，提高了树脂的交联密度；游离酚含量从改性前的4.12%降低到了2.21%,说明硼元素的引入改变了苯酚的活性，提高了树脂聚合度。     

纤维级氢氧化镁阻燃体系研究

采用一种天然矿物纤维，经特殊加工改性，制成纤维级氢氧化镁，探讨了其与高分子材料的复合性，阻然，消烟，增强等作用，并以硼酸，硬脂酸和有机硅化物为阻然增效剂，ＬＤＰＥ为基体树脂制作作了低烟阻燃材料，产品性能接近于ＥＷＣＺ－６２８７－１产品指标。     

含氧化叔胺侧基的水溶性酚醛树脂的合成与成像性能

本实验通过一锅、两步法制备改性酚醛树脂.首先利用环氧酚醛树脂F-44与二甲胺反应,得到叔胺化酚醛树脂,叔胺化树脂被双氧水氧化后得到最终目标产物,即含强极性氧化叔胺基团的酚醛树脂.实验表明,该新型树脂易溶于水和一些强极性溶剂,如四氢呋喃、乙二醇独甲醚和N,N-二甲基甲酰胺等.在热的作用下,树脂能够分解并失去水溶性,但仍可溶于一些有机溶剂.由该树脂与830 nm激光增感染料匹配使用,树脂体系对红外光敏感,并能够通过中性水显影得到较为清晰的阴图型图像,表明该树脂有望用于免化学处理热敏激光成像领域.     

气相色谱法同时测定树脂中氯化苄、苄醇和苯酚

对于通用型酚醛树脂和专用型酚醛树脂,其游离酚的分析方法通常采用容量法。但对碳素材料专用酚醛树脂,由于在生产时添加氯化苄对酚醛树脂进行改性,使树脂能浸润碳素材料的中心。这种树脂的生产过程控制和产品质量检验时,涉及游离酚、氯化苄和苄醇的分析测定,如果采用分别测定,其操作相当繁琐,准确性也不高。在常规方法蒸馏苯酚的过程中,氯化苄和苄醇也会被蒸馏出来,蒸馏出来的氯化苄和苄醇对苯酚的容量分析有干扰。在此基础之上,对氯化苄、苄醇和苯酚的蒸馏进行回收率测定,结果表明回收率满足要求。因此,本文建立了气相色谱法同时测定碳素材料专用树脂中的氯化苄、苄醇和苯酚的分析方法。即采用与容量分析方法一样的样品前期处理（酒精溶解样品、水浴蒸馏）,使游离酚、氯化苄和苄醇同时与树脂分离后,采用气相色谱法测定。本方法使测定步骤简化,可用于氯化苄改性的专用酚醛树脂的科研和生产控制。     

亚表面引发原子转移自由基聚合制备牢固的嵌入式聚合物刷

本文展示了一种新的材料表面改性方法:原子转移自由基聚合(sSI-ATRP)的亚表面修饰,即通过ATRP反应在聚合物材料界面嵌入聚合物刷,构筑稳定的、厚的聚合物亚表面层.首先,将ATRP引发剂分子通过共价键引入到丙烯酸树脂、聚氨酯、聚酯、环氧树脂等聚合物材料中,然后该基底材料在含有催化剂的单体溶液中引发表面原子转移自由基聚合.表面接枝的亲水聚合物刷使材料的表面变得亲水并发生溶胀,使得单体溶液可以进一步接触到材料内部的引发剂而引发新的ATRP反应,该过程不断重复,最后在基材表面上形成几十微米厚的聚合物刷改性的亚表面层.与传统的表面接枝的聚合物刷相比,这种嵌入式的聚合物刷赋予材料表面改性层更好的机械性能,可承受高载摩擦和更好的抗海生物附着特性,且在改性亚表面层破坏后,不需要引发剂修饰组装而再次重复引发聚合改性.     

一种加成固化型热固性树脂PN-PAA固化过程和热稳定性研究

研究了炔丙基醚化酚醛树脂(PN)与聚芳基乙炔树脂(PAA)的反应性共混物(以下简称PN-PAA共混树脂)的相容性,并对共混树脂的固化过程和固化物的耐热性进行了表征.相态、DSC、SEM、TEM等测试结果均表明共混树脂及其固化物是完全相容的均相体系.凝胶时间、粘度、DSC等结果表明共混树脂固化工艺性优良,适合多种成型工艺(如RTM),显著改善了PAA树脂的固化工艺缺陷.DMA、TGA等分析表明共混树脂固化物具有很高的耐热性,可作为新型的防热复合材料和高温结构材料的基体.     

Linseed oil‐based reactive diluents preparation to improve tetra‐functional epoxy resin properties

Two kinds of bio‐resourced reactive diluents have been synthesized from linseed oil. The prepared epoxidized linseed oil (ELO) and the cyclocarbonated linseed oil (CLO) were separately blended with a petroleum‐based tetra‐functional epoxy resin (TGDDM) to improve its processability and to overcome the brittleness of the thermoset network therefrom. The linseed oil modifications were spectrally established, and processability improvement of the resin blends was rheologically confirmed. The curing of samples was studied by differential scanning calorimetry, and their mechanical properties (ie, tensile, flexural, fracture toughness, and adhesion) were investigated as well. Scanning electron microscopy images were obtained to reconfirm the toughness improvement of the modified thermosets. In contrast of the epoxidized soybean oil (ie, the most conventionally studied bio‐based reactive diluent), ELO and CLO had no negative effects on the thermoset material characteristics. They improved properties such as tensile strength (up to 43.2 MPa), fracture toughness (1.1 MPa m^1/2), and peel‐adhesion strength (4.5 N/25 mm). It was concluded that ELO and CLO were efficient reactive diluents to be used in formulations of polymer composites, surface coatings, and structural adhesives based on epoxy resins.     

Synthesis and application of phenolic resin internally toughened by chain extension polymer of epoxidized soybean oil

A novel epoxidized soybean oil (ESO) internally toughened phenolic resin(ESO-IT-PR) with both good toughness and excellent thermal stability was prepared as the matrix resin of copper clad laminate (CCL). FTIR was adopted to investigate the molecular structure of modified phenolic resins and SEM was used to observe the micro morphology of their impacted intersections. The properties of CCLs prepared with these modified phenolic resins were studied to determine the optimal process and investigate the toughening mechanism. The main modifying mechanism is the etherification reaction between phenol hydroxyl and ESO catalyzed by triethanolamine and the chain extension polymerization between ESO and multi-amine gives the long-chain ESO epoxy grafting on the phenolic resin prepolymer. when the ESO content is 30% and the curing agent content is 7%, the ESO toughened phenolic resin possesses optimal performance. The flexible ESO epoxy shows significant toughening effect and it crosslinks with the phenolic resin to form an internally toughened network, which is the key factor for improving the solderleaching resistance of CCL prepared with this modified phenolic resin. __________ Translated from Journal of South China University of Technology (Natural Science Edition), 2007, 35(7): 99–104 [译自: 华南理工大学学报(自然科学版)]     

丁腈弹性纳米粒子改性酚醛树脂的研究

酚醛树脂具有优异的耐热性、电绝缘性,尺寸稳定性、成型加工性和阻燃性等,广泛地应用在涂料、胶粘剂和复合材料工业上,酚醛树脂由于含有大量苯环以及固化后形成高度交联结构,韧性很差,因此增韧是其高性能化的主要方向之一,橡胶是最广泛使用的增韧剂,几十年来发展了天然橡胶、丁腈橡胶、丁苯橡胶、液体羧基丁腈橡胶、丁吡橡胶等,壬基酚、腰果壳油、桐油、亚麻油、热塑性塑料等也是酚醛树脂有效的增韧剂。     

Synthesis and Characterization of a Bio-Based Resin from Linseed Oil

Summary: The use of renewable raw materials in the polymer industries is becoming increasingly popular because of environmental concerns and the need to substitute fossil resources. Plant oils with triglyceride backbones can be chemically modified and used to synthesize polymers from renewable resources (biopolymers). In the present study, linseed oil was epoxidized using a chemo-enzymatic method based on Candida Antarctica lipase B (CALB) as a biocatalyst and the modified linseed oil was cured using maleinated linseed oil and a commercial polyamide resin. The amount of epoxidation achieved depended on the amount of lipase used and was determined by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies. With 20% (weight per weight) catalyst concentration based on the wt % of oil a degree of epoxidation of > 90% was achieved. The cross-linking reaction of epoxidized linseed oil with the maleinated linseed oil and the polyamide resin was studied using differential scanning calorimetry (DSC). DSC traces showed that an increase in epoxidation degree lead to larger values for the exothermic enthalpy integrals of the curing reactions and hence to a higher reactivity of the linseed oil towards the cross-linking agents.     

Synthesis of urethane acrylates modified by linseed oil and study on EBC coatings

In this paper, five different structural urethane acrylates modified by linseed oil were synthesized and then properties of their electron beam cured (EBC) coatings, i.e., adhesion, gloss, flexibility, impact resistance, hardness, tensile strength and elongation were studied. It was shown that these synthesizing conditions of urethane acrylates modified by linseed oil were temperate. Effect of structure of urethane acrylates modified by linseed oil on these properties of their EBC coatings was obvious, except gloss. According to synthetical properties of EBC coatings, the optimum oligomer among these was No. A, whose main chains were formed by hexane diacid, average functionality was 2, and oil content was 25.5%. With increasing of absorbed doses, these properties of EBC coatings, except gloss, changed correspondingly. It was advisable that absorbed dose wasn’t greater than 180 kGy. At higher absorbed doses, cobaltous naphthenate had obvious effect on these properties of EBC coatings, whose oil content of linseed oil was rather high.     

低聚端羟基聚硅氧烷接枝增韧酚醛树脂的制备及性能

由低聚羟基封端聚硅氧烷（HO-PDM）与甲醛和苯酚的接枝反应制备了增韧改性酚醛树脂,用FT-IR对改性酚醛树脂的结构进行表征,用电子万能试验机测试了改性前后酚醛树脂的力学性能,用热重分析仪测试改性酚醛树脂的热稳定性。 测得改性酚醛树脂的断裂伸长率、冲击强度、抗拉强度分别为2.8%、2.875 kJ/m2和23.2 MPa;树脂失重20%的温度为431.28 ℃,峰值温度为441.8 ℃,800 ℃的残重率为51.02%。     

INTERPENETRATING POLYMER NETWORKS BASED ON OIL MODIFIED CASTOR OIL URETHANE AND POLY(METHYL METHACRYLATE)

Castor oil was initially subjected to an interesterification reaction with linseed and tung oils and the resulting intermediate was used for the preparation of polyurethanes and their IPNs with poly(methyl methacrylate). They were characterized for their physico-mechanical, swelling, and thermal properties. The morphologies of IPNs were studied with the aid of scanning electron microscopy and differential scanning calorimetry. On comparing the mechanical properties of castor oil polyurethane (CU) and their IPNs (C-IPNs) with those of the castor oil modified with linseed and tung oil (L-IPN and T-IPN, respectively) it was found that L-IPNs showed higher tensile strength, hardness, and better compatibility than C-IPNs. All IPNs showed synergistic effect in elongation and exhibited similar thermal behavior with no significant change with respect to their composition. However, the castor oil polyurethane and their IPNs showed relatively higher elongation and better resistance to solvents.     

A 19th Century “Ideal” Oil Paint Medium: A Complex Hybrid Organic–Inorganic Gel

British 19th century painters such as J. M. W. Turner, commonly modified the properties of their paint by using gels called “gumtions”. These gels allowed them to easily tune the paint handling and drying properties. The fascinating properties of these “gumtions” were obtained by adding lead acetate to a ternary system based on mastic resin, linseed oil and turpentine. Herein, we report and investigate in depth the rheological properties of these gels as well as their structure at a molecular and supra‐molecular scale.     

水性聚氨酯甲阶酚醛水分散液微观形态及杂化膜的性能

以自乳化型聚氨酯和甲阶酚醛制备了聚氨酯 酚醛复合水分散液 .pH值与酚醛溶解度的关系表明甲阶酚醛的溶解是酚羟基电离的结果 .聚氨酯 甲阶酚醛水分散液粒子的形态有核壳结构、不完善的核壳结构及纯聚氨酯颗粒三种 ,后者粒径最小 .随着酚醛用量的增大 ,粒子平均粒径增大 .酚醛含量增加使体系热稳定性、机械稳定性、冻融稳定性及临界聚沉值下降 ,pH值稳定范围变窄 .分散液稳定性和电性能考察证明 ,本复合分散液的稳定性主要由分散液的电性能所决定 ,属真溶胶 ,但在一定程度上也具有大分子溶液的特性 .复合液涂膜的性能较纯聚氨酯有所改善 ,尤其在添加了硅溶胶之后     

Thermal,mechanical, and morphological properties of novolac‐type phenolic resin blended with fullerenol polyurethane and linear polyurethane

Fullerenol polyurethane (C₆₀‐PU) and linear polyurethane (linear‐PU) modified phenolic resins were prepared in this study. Phenolic resin/C₆₀‐PU and phenolic resin/linear‐PU blends show good miscibility as a result of the intermolecular hydrogen bonding existing between phenolic resin and PU modifiers. DSC and thermogravimetric analysis methods were used to study the thermal properties of phenolic resin blended with different types of PUs. The intermolecular hydrogen bonding that existed between phenolic resin and C₆₀‐PU was investigated by Fourier transform infrared spectroscopy. The morphology and mechanical properties of phenolic resin/C₆₀‐PU and phenolic resin/linear‐PU blends were also investigated. The char yield of the modified phenolic resins decreased with increasing PU modifier content. Significant improvement in the toughness of the modified phenolic resins was observed. The improvements of impact strength were 27.4% for the phenolic resin/linear‐PU system and 54.3% for the phenolic resin/C₆₀‐PU system, respectively, both with 3 phr linear‐PU and C₆₀‐PU content. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2436–2443, 2001