电子束固化环氧树脂混合体系的研究

对几种环氧树脂混合体系的电子束固化进行了研究。比较了环氧８２８、６４８、２０７树脂及其混合体系的辐射效应。分析了树脂配比及辐射剂量对环氧８２８／６４８树脂混合体系的影响；测试了不同树脂配比的环氧２０７／６４８树脂混合体系辐射产物的性能。结果表明，环氧树脂的化学结构、空间效应以及结晶性等其辐射效应有很大影响，通过不同环氧树脂的配合，可以改善体系的辐射固化效果，减少辐射剂量，提高辐射产物的性能。     

含磷、氮活性单体的电子束辐射固化

用含磷、氮活性单体实现了空气中电子束辐射固化，研究了不同含磷，氮化合物的抗氧抑制效果及磷，氮化合物的浓度和辐射剂量等因素对电子束固化的影响。获得了磷，氮化合物的最佳使用浓度及辐照剂量对电子束固化的影响规律，提出了磷，氮化合物的抗氧抑制机理。     

环氧树脂电子束辐射效应研究

为了研究不同结构的环氧树脂在电子束辐射条件下的辐射化学行为及其对环氧树脂辐射固化行为与性能的影响。通过对环氧树脂电子束辐射前后的粘度变化、加热失重率以及辐射产生的小分子的对比研究发现,各种环氧树脂在电子束辐射下均有不同程度的辐射分解反应发生。其中,以缩水甘油酯型环氧树脂和含酯基的环氧树脂的分解最为严重,缩水甘油胺环氧树脂次之,缩水甘油醚环氧树脂受电子束辐射的降解影响最小。     

慢正电子束研究电子束固化涂层的微观结构

用慢正电子束多普勒展宽谱研究环氧丙烯酸酯体系电子束固化涂层。Ｓ－Ｅ曲线给出了稀释剂分子结构及其相对含量，辐射剂量，预聚物和交联剂含量等对ＥＢＣ涂层 观结构的影响，以及随深度变化的信息。     

环氧树脂固化放射性废树脂的配方初探北大核心CSCD

为了将中、低放射性废树脂固化成稳定的固化体,采用环氧树脂为基材,通过添加合适的固化剂、稀释剂、阻燃剂等进行固化配方试验研究。结果表明,配方为E-44环氧树脂∶651固化剂∶添加剂=1∶0.53∶0.05(38∶20∶2)、质量包容率50%时,其固化体性能最优,并满足国标GB 14569.2的要求,研究结果表明采用环氧树脂体系固化放射性废树脂是可行的。     

废树脂苯乙烯固化研究(Ⅱ)

本文研究废离子交换树脂苯乙烯固化的工艺条件和固化产品性能鉴定。该法能包容62％(W)废树脂。固化产品均匀、坚韧、抗压强度239kg/cm~2。在去离子水中浸泡120d,浸出率对于~(137)Cs为10~(-6)cm/d,对于~(60)Co和~(85)Sr为10~(-7)-10~(-8)cm/d。长期水浸不溶胀。承受辐照剂量>10~8rad。闪点270℃,燃点290℃左右。加热到450℃不自燃,DTA曲线上235℃前无放热峰。     

氧化预聚亚麻油的电子束固化

氧化预聚亚麻油的结构决定了其电子束固化除膜具有光泽度好，硬度小，柔韧性和冲击强度优良，玻璃化转变温度低，对马口铁板等极性基材的附着力差等性能；它不仅能作为顶聚体，而且，还能作为功能单体与其它组分复合使用，并能显著改善复合体系的涂膜性能；在一定范围内，吸收剂量和环烷酸钴对基固化涂膜的性能影响程度小。     

先进复合材料-电子束固化新应用

先进复合材料是由环氧树脂为基体相、高级合成纤维为增强相构成,具有高比强度和比模量,质轻,抗疲劳,耐腐蚀,尺寸稳定性等特点,在航天航空、国防军工、高压容器、汽车、运动器材等方面得到广泛应用.用电子束固化取代热固化具有安全、节能、环保等优点.本工作介绍先进复合材料电子束固化工艺优点、先进复合材料性能和国内外发展状况.     

模拟动力堆高放废液玻璃固化体的析晶行为及其对浸出率的影响北大核心CSCD

玻璃固化技术是国内外目前主要的高放废液固化处理手段。针对模拟高燃耗动力堆高放废液,研究了废物氧化物包容量为24%(质量分数,下同)和30%时玻璃固化体在不同热处理温度下的析晶行为以及析晶对玻璃固化体抗浸出性能的影响。根据X射线衍射、拉曼光谱和扫描电子显微镜分析结果,当热处理温度为800℃时,玻璃固化体析出晶体相为树枝状的钼酸钙CaMoO_(4)和丝状的锆铈氧化物Zr_(x)Ce_(1-x)O_(2);当热处理温度为950℃时,除钼酸钙和锆铈氧化物之外,玻璃固化体中还有大量的空心六方柱形的硅氧磷灰石相Ca_(2)Ln_(8)(SiO_(4))_(6)O_(2)析出。根据抗浸出性能检测结果,玻璃固化体经热处理析晶后其归一化质量损失降低了约1/3,B、Na、Mo、Ca等的归一化质量损失也有明显下降。且950℃热处理比800℃热处理后的玻璃固化体归一化质量损失更小。结果表明热处理析晶可提升玻璃固化体抗浸出性能。     

双酚A型环氧树脂的1.5 MeV电子束辐照效应

本工作以双酚A型环氧树脂为研究对象,在1.5 MeV电子加速器下分别以18 kGy/h和2 250 kGy/h的剂量率对其进行辐照处理,以达到总吸收剂量135 kGy、270 kGy、500 kGy和1 000 kGy。系统研究了两种不同剂量率和不同吸收剂量对环氧树脂表面形貌、化学结构和热性能的影响。结果表明：电子束辐照环氧树脂时,高剂量率下环氧树脂内部会产生脉状裂纹,而总吸收剂量对树脂的热稳定性和力学性能影响较大;环氧树脂经电子束辐照后,玻璃化转变温度和交联密度下降,同时力学性能下降,表明辐射裂解占主导;电子顺磁共振光谱测试表明辐照过程中有烷基自由基和过氧自由基的产生,自由基浓度与吸收剂量呈正相关性。进一步研究了自由基在空气中的稳定性,随着存放时间的增加,自由基浓度最终趋于稳定。     

Fixation of Photoelastic Fringe Patterns by Gamma-Rays

In the present experiment, the effects of differences in the weight ratio between the epoxy resin and curing reagent, and in the radiation dose on the amount of residual fringe patterns were studied in detail. The specimens contained 12, 16, 20 and 25 (weight) parts of curing reagent for 100 parts of epoxy resin, and the radiation dose was varied in steps of 0.53×10⁸, 1.16×10⁸, 1.92×10⁸ and 3.17×l0⁸R on the average. The optical and mechanical properties of epoxy resin were also compared between non-irradiated and irradiated specimens for: Photo-elastic sensitivity, modulus of elasticity, Poisson's ratio and Rockwell's hardness. The relationship between the chemical and radiation crosslinking was obtained in an endeavor to throw light on the reason why the amount of residual fringe patterns depended on the epoxy resin/curing reagent weight ratio and on the radiation dose. It was also shown that the change and disturbance in the patterns depended on optical creep, time edge-effect and on the generation of gases by irradiation.     

A study on physicochemical properties of epoxy coating system for nuclear power plants

In this work, the thermal properties of epoxy coating system on the liner plate in the containment structure have been investigated by irradiation dose rate and design basis accident (DBA) conditions. Also, the effect of immersion in hot water on adhesion strengths of epoxy coating system has been studied. The glass transition temperature (T_g) and thermal stability of the epoxy coating system after DBA tests were measured by differential scanning calorimeter (DSC) and thermogravimetric analyser (TGA) analyses, respectively. Contact angle measurements were used to determine the effect of immersion on the surface energetics of epoxy coating system, including surface free energy and work of adhesion. Adhesion tests were also executed to evaluate the adhesion strength at interfaces between carbon steel plate and epoxy resins. As a result, the DBA test led to the improvement of the internal structure in cured epoxy systems, resulting in significantly increasing the thermal stability, as well as the T_g. Also, the immersion in hot water had a role in the post curing of epoxy resins and increased the mechanical interlocking of the network system, resulting in increasing the adhesion strengths of the epoxy coating system.     

高分子链柔顺性及链活动能力对辐射交联反应的影响

高分子分子链的柔顺性是影响辐射交联的重要因素，分子链柔顺性好的高分子容易交联，凝胶化剂量低，反之分子链较僵硬的高分子辐射交联较困难，某此特别僵硬分子链的高分子，必须在高温下，分子链有一定的活动力后才能进行辐射交联反应。分子链的柔顺性还影响裂解度和辐照剂量的关系，在溶胶分数和辐射剂量的关系式中引入表征分子链柔顺性的β因子，从而修正了Charlesby-Pinner关系式，得到适用范围更广的新的溶胶分数和辐射剂量的关系式。分子链的柔顺性亦影响辐射交联反应机理，从多种高分子实例看出，柔顺性好的高分子Tg较低，分子内旋转位阻因子小，这类高分子辐射交联反应机理以H型为主；而僵硬链高分子Tg较高，分子内旋转位阻因子大，这类高分子辐射交联反应机理以T型（或称Y型）为主。     

超高分子量聚乙烯的辐照效应

通过密度测定和ＤＳＣ热分析，观测了超高分子量聚乙烯的辐射效应。实验结果表明：在吸收剂量０—１．１３ＭＧｙ范围内，密度随吸收剂量的增加而增大，熔化热和熔点也有所增加，特别是在低剂量范围内增加十分明显。以上结果都说明，超高分子量聚乙烯在辐照过程中，结晶在完善或有新的结晶形成     

γ射线辐照对超高分子量聚乙烯片材机械性能和结晶度的影响

采用钴源以剂量率为2.5 k Gy·h~(-1)的γ射线对超高分子量聚乙烯(Ultra-high Molecular Weight Polyethylene,UHMWPE)片材在空气、水、甲醇和乙醇氛围中进行了辐照,吸收剂量范围为0 200 k Gy。通过机械性能、凝胶含量、差示扫描量热仪(Differential Scanning Calorimetry,DSC)、傅里叶变换红外光谱仪(Fourier Transform Infrared Spectrometer,FTIR)等对不同辐照氛围中辐照前后UHMWPE样品进行了测试和表征。机械性能测试结果表明,在空气中UHMWPE的断裂伸长率随吸收剂量呈幂指数下降,同时屈服强度略有下降,而在水、甲醇、乙醇为辐照体系中UHMWPE的断裂伸长率随吸收剂量也是呈下降趋势,但下降的程度依次减轻,同时屈服强度基本保持不变;DSC测试结果显示,在空气氛围中,随着吸收剂量的增加,UHMWPE样品的初始熔融温度、熔点、结晶温度和结晶度逐渐降低;而在空气、水、甲醇和乙醇氛围中,UHMWPE样品的初始熔融温度、熔点和结晶度依次上升;红外光谱测试结果显示在空气中辐照,UHMWPE样品表面随着吸收剂量的增加其氧化程度加重,而在水、甲醇和乙醇中辐照UHMWPE分子链生成了不饱和的分子双键。     

Study of electron beam curing process using epoxy resin system

Polymeric matrix composite (PMC) has been used in engineering applications instead of metal in the last few years, due to its corrosion resistance and excellent relation between tensile strength/density and elastic modulus/density. However, PMC materials cured by thermal process require high temperature and are time-consuming. The electron beam (EB) curing technology allows its use at room temperature and reduced curing times, and this is one of the main advantages over thermal technology. The aim of this work is to investigate electron beam curable epoxy formulations to use in filament winding processes to produce composite material with similar or better properties than thermal curable composites. The study has been made with commercial epoxy resins and cationic initiators. The epoxy resin samples were irradiated for few minutes with total dose of 150 kGy. The glass transition temperatures (T_g) were determined by dynamic mechanical analyzer (DMA) and the result was 137 °C. The thermal process was carried out in a furnace following three steps: 4 h at 90 °C, increasing temperature from 90 °C to 130 °C during 4 h and 12 h at 130 °C. The total process time was 20 h. The T_g of this sample was 102 °C.     

空气中两种辐照场下聚碳硅烷先驱丝的辐照不熔化效应

采用⁶⁰Co产生的γ射线与10MeV电子加速器产生的电子束在空气中辐照聚碳硅烷先驱丝。利用凝胶含量测定、红外光谱分析、凝胶渗透色谱分析、热重分析等手段研究了经两种辐照场辐照后聚碳硅烷先驱丝的凝胶含量、化学结构、分子量分布及其热分解特性的变化。结果表明：两种辐照场下能满足聚碳硅烷先驱丝不熔化处理的剂量分别为3、6.5MGy,两种辐照场下聚碳硅烷先驱丝的辐照不熔化机理一致,均通过形成Si—C—Si、Si—O—Si桥联结构而实现不熔化处理;在相同吸收剂量下,γ射线辐照不熔化效果较电子束辐照的好;γ射线辐照的聚碳硅烷先驱丝陶瓷产率也较电子束辐照的高。     

聚氨酯改性丙烯酸环氧单酯的光-热固化性能

合成了聚氨酯改性丙烯酸环氧单酯,树脂分子结构中同时具有光固化基团(双键)和热固化基团(环氧基团).用FTIR表征了光-热固化过程特征吸收峰的变化.研究了不同的稀释剂、热固化剂对光固化和光—热混杂固化的凝胶率、吸水率、力学性能和热性能的影响,结果表明:光固化膜的凝胶率低于89％,而光—热混杂固化膜的凝胶率在97％左右.在...