光稳定剂对热塑性聚氨酯胶粘剂性能的影响

采用一步法合成耐黄变热塑性聚氨酯(TPU)胶粘剂,研究了紫外线吸收剂UV-329、受阻胺光稳定剂UV-622、抗氧剂Chinox1010等对TPU胶粘剂性能的影响。结果表明,当UV-329、UV-622、Chinox1010质量比为3∶3∶2,且复合光稳定剂添加质量分数1.6%时,可提高TPU胶粘剂的耐黄变性能,有效延缓TPU胶粘剂的光老化速度。     

LED封装用改性环氧树脂研究进展

传统的LED环氧树脂封装材料存在脆性大、耐冲击性差、容易老化、透光率低、折射率低等缺陷,限制了其在LED封装产业中的应用,通过环氧树脂改性可弥补其作为LED封装材料的缺陷。本文综述了近年来LED环氧树脂封装材料在高折射率、光稳定、抗黄变、有机硅改性方面的研究进展,并展望了LED改性环氧树脂封装材料的发展前景。     

聚丙烯耐老化改性研究

分别采用抗氧剂(1010或1076)及光稳定剂(UV-531或UV-770)作为抗老化助剂对聚丙烯(PP)进行了改性,考察了两类抗老化助剂对PP耐老化性能的影响。结果表明:两类抗老化助剂的添加分别改善了PP的耐热氧老化性能和耐紫外光老化性能。其中,抗氧剂1010对PP耐热氧老化性能的改善效果优于1076,二者的适宜添加量均为0.2%左右;光稳定剂UV-531对PP耐紫外光老化性能的改善效果优于UV-770,二者的最佳用量约为0.3%左右。     

PVC/改性剑麻纤维木塑复合材料的紫外加速老化性能研究

采用KH-550偶联剂对剑麻纤维进行改性处理,然后与聚氯乙烯（PVC）树脂、光稳定剂以及其他助剂通过塑炼、模压成型制备PVC基木塑复合材料板材,然后对其进行紫外加速老化试验。光稳定剂为自制的3种二苯甲酮类聚合型光稳定剂P(HABP-co-MTMP-co-OA)、P(HABP-co-MTMP-co-mPEGA)、 P(HABP-co-MTMP-co-OA-co-mPEGA)与目前常用的紫外线吸收剂UV-0、UV-531。测试了老化前后的拉伸强度保持率、表面接触角、热萃取损失率变化情况对PVC/改性剑麻纤维复合材料的紫外光老化性能的影响。结果表明,添加高分子光稳定剂的PVC/改性剑麻纤维复合材料具有优于添加UV-0、UV-531紫外光吸收剂的综合耐紫外光老化性能,尤其是P(HABP-co-MTMP-co-OA-co-mPEGA)光稳定剂对木塑复合材料的紫外光老化效果最好;3种高分子光稳定剂的添加使PVC/改性剑麻纤维复合材料的表面纤维裸露程度以及微小裂纹明显少于未添加光稳定剂的PVC/改性剑麻纤维复合材料。     

LED封装用有机硅改性环氧树脂的研究进展

从LED封装用有机硅改性环氧树脂材料的制备方法、固化及性能3个方面综述了最近几年封装材料的发展状况,并对LED封装用有机硅改性环氧树脂材料未来的发展方向进行了展望。     

受阻胺类光稳定剂改性文物保护材料B72

为了提高B72文物保护材料的耐光性能,采用HALS-622等6种受阻胺光稳定剂对丙烯酸类文物保护材料B72进行改性。结果表明,HALS-5060稳定剂在添加后及老化过程中颜色明显变黄,不宜用作B72改性材料。高相对分子质量(简称分子量,以下同)受阻胺HALS-622、HALS-944比低分子量受阻胺HALS-480、HALS-508和HALS-292稳定效果好,尤其是低碱性的HALS-622受阻胺。因此,采用高分子量、低碱性的受阻胺改性B72是延长其使用寿命、对文物进行有效保护的新途径。     

高功率型LED封装新材料的研究进展

随着发光二极管(LED)功率和亮度的不断提高,封装材料已成为制约LED进入照明领域的关键技术之一。综述了改性环氧树脂和有机硅LED封装材料的研究进展,并展望了改性环氧树脂和有机硅LED封装材料的发展前景。     

功率型LED封装材料的研究进展

指出了环氧树脂作为目前LED主流的封装材料性能的不足,分析了目前改性环氧树脂、有机硅改性环氧树脂、有机硅树脂等做为功率型LED封装材料的优点和局限。综述了国内外主流的环氧树脂、有机硅改性环氧树脂、有机硅树脂等封装材料的研究进展。展望了功率型LED封装材料的发展趋势。     

受阻胺类光稳定剂改性文物保护材料B72研究

为了提高B72文物保护材料的耐光性能,采用HALS-622等6种受阻胺光稳定剂对丙烯酸类文物保护材料B72进行改性。实验结果表明, HALS-5060稳定剂在添加后及老化过程中颜色明显变黄,不宜用作B72改性材料。高分子量受阻胺HALS-622、HALS-944比低分子量受阻胺HALS-480、HALS-508 和HALS-292稳定效果好,尤其是低碱性的HALS-622受阻胺。因此,采用高分子量、低碱性的受阻胺改性B72是延长其使用寿命、对文物进行有效保护的新途径。     

LED封装用高分子材料的研究进展

综述了国内外发光二极管（LED）封装用高分子材料的研究进展,包括环氧树脂、改性环氧树脂、有机硅树脂等,指出了今后功率型LED封装用高分子材料的研究方向,认为高性能有机硅树脂将成为高端LED封装材料的封装方向之一。     

Effect of crosslinking agent on the properties of low-temperature curing PES/PTFE anticorrosive coating

To reduce energy consumption and broaden the scope of application of polyethersulfone/polytetrafluoroethylene (PES/PTFE) coatings, three hybrids have been designed by incorporating PES/PTFE coatings with different contents (0, 10, and 20 wt %) of crosslinking agent consisting of epoxy resin and appropriate curing agent (ER-CA) in the application as low-temperature curing PES/PTFE coatings and named as EP-0, EP-1, and EP-2, respectively. The addition of ER-CA gives rise to satisfactory distribution of PTFE, making PTFE play its roles better and improves barrier properties of the coatings by secondary leveling and its own crosslinking structure, which greatly enhances anticorrosion properties. Compared with EP-0 and EP-2, EP-1 exhibits lower water permeability. Even after long-term exposure to corrosive environments, EP-1 still possesses high anticorrosion properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48740.     

液晶化合物增韧改性耐高温环氧树脂的研究

通过4氨基苯酚与对苯二甲醛加成缩合反应合成一种新型西佛碱单体(DP-1),然后通过DP-1与环氧氯丙烷在碱性条件下合成环氧化合物(EP-1)。对EP-1结构进行了傅里叶红外变换光谱、核磁共振、差示扫描量热分析,分析了其性能。通过EP-1对耐高温环氧树脂(AG-80)进行增韧改性,以4,4’-二氨基二苯砜（DDS）为固化剂,研究AG-80/DDS/EP-1固化体系的力学性能和热性能。结果表明,成功合成了一种新型液晶型环氧化合物EP-1,当EP-1含量为5 %时,冲击强度为23.27 kJ/m2;弯曲强度为126.39 MPa;弯曲模量为4.14 GPa;热变形温度为232.5 ℃。     

绢云母改性及其对环氧涂料性能的影响

用硅烷偶联剂KH-570分别对绢云母进行表面改性,并将改性绢云母分别添加到环氧树脂涂料。用红外光谱(FT-IR)、接触角试验及扫描电镜等对改性效果进行表征。试验结果显示:偶联剂成功地包覆于绢云母表面。通过偶联剂包覆改性,使绢云母在环氧树脂涂料中的分散性得到提高,明显增加了其与环氧树脂涂料的相容性。交流阻抗(EIS)测试结果表明,改性后的绢云母的添加明显提高了涂料的防腐性能。     

气相SiO_2对环氧树脂的乳化稳定作用

研究了气相SiO2对环氧树脂E-44的乳化稳定作用。结果表明:气相SiO2的表面性质对环氧树脂E-44的乳化稳定作用有较大影响,未改性的气相SiO2没有乳化作用,阳离子表面活性剂十二烷基三甲基溴化铵(DTAB)、十六烷基三甲基溴化铵(CTAB)改性的气相SiO(2DTAB-SiO2、CTAB-SiO2)能形成较稳定的O/W乳状液,其中用浓度为1×10-3mol/L、接触角为84.1°的CTAB改性气相SiO2得到的乳状液稳定性最好。CTAB-SiO2与环氧树脂专用乳化剂EP-1合用形成的乳状液为W/O/W型多重乳液。     

含有环氧基的丙烯酸酯的合成及其固化物的研究

采用脂肪族环氧树脂(EP-664)与丙烯酸(AA)合成了低黏度的含有环氧基的丙烯酸酯(AEG),该反应性酯类化合物与双酚A型环氧树脂(E-44、EP-6002)共混,以甲基六氢苯酐(MeHHPA)为固化剂,并分别采用三级胺和2-乙基-4-甲基咪唑(2E4MZ)为促进剂,通过混合物黏度曲线的变化与其固化物力学性能的测试,研究了AEG含量对环氧树脂体系黏度的变化和固化物力学性能的影响。结果显示,AEG的添加可以有效地降低树脂体系的黏度,25℃下混合体系黏度仅为300～600mPa·s;其固化物的力学性能随AEG含量的增加先增加后降低,具有最大值。三级胺固化体系的力学性能明显优于2E4MZ固化体系,当w(AEG)为20%时,固化物的综合力学性能最好。     

A multi-element flame retardant for rail transit to improve the flame retardant performance of epoxy resin while reducing smoke density

A P/N/Si structure flame retardant DTBD was successfully synthesized by 3,5-diaminobenzoic acid, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), triphenylsilanol, and benzaldehyde. The chemical structure of DTBD was analyzed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectra, which showed that DTBD was successfully synthesized. By analyzing the curing behavior, the addition of DTBD promoted the curing of epoxy resin (EP). According to the limited oxygen index (LOI) and UL-94 vertical combustion tests, it can be shown that the introduction of DTBD makes the epoxy resin have good self-extinguishing properties. Py-GC/MS analysis showed that the phosphorus free radicals and ammonia generated in the gas phase of DTBD could quench and dilute by capturing reactive free radicals and refractory gases. DTBD could improve the tensile and flexural properties of epoxy resin. According to the European flame retardant standard EN45545-2, the Ds of EP-15 and EP-20 obtained HL1 grade. With the increase in DTBD content, the VOF₄ of modified EP also gradually decreased, and both EP-15 and EP-20 obtained HL2 grade.     

Curing behavior and properties of epoxy resins cured with the diamine having the quinoxaline or triazine structure

2,3-Bis(4-aminophenyl)quinoxaline (1a), 2,3-bis(4-aminophenyl)-6-methylquinoxaline (1b), and 5,6-bis(4-aminophenyl)-3-(2-pyridyl)-1,2,4-triazine (2) were studied as curing agents of epoxy resins. The exotherms on differential scanning calorimetry thermograms of the mixtures of diglycidyl ether of bisphenol A (DGEBA) with 1a, 1b, and 2 were observed at higher temperatures than that of the mixture of DGEBA with a commercially used diamine, for example, 4,4′-diaminodiphenylsulfone (DDS). However, the epoxy resin cured with 1a (EP-1a) showed higher tensile strength to stainless steel at 20°C than that cured with DDS, and the high tensile strength of EP-1a was maintained even at 180°C. The epoxy resin cured with 1b or 2 also possessed higher tensile strength at 20°C than that cured with DDS, but the high tensile strength lowered somewhat at 120°C. Using diamines 1a, 1b, and 2 as a curing agent improved heat distortion temperatures of the cured epoxy resins. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 69: 1737–1741, 1998     

风电叶片用真空灌注型环氧树脂及其复合材料性能研究

本文针对两种自制的风电叶片用真空灌注型环氧树脂体系EP-1和EP-2,研究了树脂的工艺性和力学性能,并选取单轴向和三轴向玻璃纤维织物,采用真空灌注工艺制备了复合材料层板,考察了复合材料在室温和高低温下的力学性能。结果表明,EP-2体系浸润性、流动性和韧性更好,但强度、模量和耐热温度略低;常温及-45℃下两种树脂基复合材料的力学性能相近,纤维/树脂界面粘结较强;50℃环境下,复合材料的压缩强度降低,受玻璃化转变温度偏低的影响,EP-2复合材料压缩性能降低更为明显;两种环氧树脂的工艺性和力学性能优异,与纤维匹配性好,满足风电叶片对树脂的性能要求。     

Investigation and Development of Epoxy Foams

The development of low toxicity rigid epoxy foams as an alternative to polyurethane foams for electronics encapsulation is described. The basic foam components - epoxy resin, hardener, accelerator, blowing agent and surfactant - are blended to form a two part system which is mixed and foamed when required. Each foam component is selected for its contribution to the foaming reaction and the final foam properties. The balance of component miscibility, viscosity, reaction rate and exotherm determine foam quality. Foam properties are affected by (1) density (2) cell structure and (3) the molecular structure of the reactants. Initial foam development utilised epoxy/amine chemistry and produced two foams, Feldex F3 and F4. Subsequently, use of a more reactive polymercaptan hardener improved foam strength and process times, resulting in Feldex F5 and F6 which have been used successfully to prepare quality mouldings and encapsulated electronics. Recently, development has been extended to new areas of application, e.g. high temperature foams. The mechanical, electrical, thermal and chemical properties of the best epoxy foams have been evaluated; selected results are reported. The epoxy foams developed offer low density, high strength, low dielectric constant and loss tangent, high volume resistivity, good thermal insulation, low corrosivity and low toxicity. In addition, epoxy foams soften in acetone, an advantage over their polyurethane counterparts since encapsulated electronics may be retrieved without employing corrosive solvents. (Feldex is a registered trade mark of THORN EMI Electronics.)     

Oxidation of PCE with a UV LED Photocatalytic Reactor

This paper is the first to investigate photocatalysis using a cutting‐edge and energy‐efficient solid‐state light source: Ultraviolet (UV) Light Emitting Diodes (LED's). UV LED's do not involve mercury vapor, can be driven with direct current (DC), and have a long lifetime of 100 000 hours. UV LED's with a peak wavelength of 375 nm were tested for perchloroethylene (PCE) photocatalytic oxidation over Degussa P–25 TiO₂. At a UV light output of only 49 μW/cm², the designed reactor delivers a PCE conversion of up to 43 %. If the UV LED price continues to drop, it is very likely that UV LED's will replace UV lamps as the favored light source in photocatalysis applications.