环氧树脂分子量对电子束辐射固化效果的影响

研究了分子量对于环氧树脂电子束辐射固化行为的影响规律。环氧树脂体系的辐射反应速率随分子量增加而下降,在低辐射剂量下,高分子量树脂的固化度和固化层厚度较小,提高辐射剂量,分子量的影响减弱。对于辐射固化程度较高的样品,其玻璃化温度(Tg)和贮能模量(E’)主要受固化度控制。电子束辐射固化的环氧树脂进行热处理后,样品的玻璃化温度和高温E’均有所提高,低分子量树脂的热处理效果更为明显。     

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。     

γ辐射对POE/MH/AH/P阻燃性能的影响

研究了γ辐射对填充氢氧化镁、氢氧化铝和红磷的聚烯烃弹性体（Polyolefin elastomer,POE）的阻燃性能的影响。经γ射线辐照后,含磷阻燃体系的氧指数较不含磷的显著提高,并且在一定剂量内随着交联程度的增加而增加;经扫描电子显微镜对燃烧后的成炭形貌观察,发现含红磷的体系交联后的炭层的致密程度增加;经热重分析,表明阻燃体系辐射后的残炭量较辐射前的略高,同剂量下的含磷阻燃体系的残炭量要明显高于不含磷的体系;同时力学性能一并得到了测试。     

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。     

利用低能自屏蔽电子帘式加速器进行木器表面涂料辐照固化的研究

本文初步描述了利用低能自屏蔽电子帘式加速器固化木器涂料和石膏板表层涂料的生产工艺。讨论了电子束固化过程中的质量控制,诸如表层涂料的涂布技术,涂层厚度对表面性能的影响,电子束辐照场下的剂量值与剂量分布等。合成了作为EB涂料主要成分的不饱和聚酯树脂。比较了几种不同种类的EB涂料的固化条件并且对固化后涂层性能作了表述。     

高放废物处置库近场剂量场及温度场的耦合计算

计算了高放废物处置库固化体内外的辐射剂量场,并将之作为热源叠加到温度场计算方程,使剂量场与温度场耦合起来,在温度场计算中,不仅考虑了固化体内存在的剂量场对其的影响。而且考虑了固化体外存在剂量场的影响。模拟结果表明,固化体外存在的剂量场对温度场有一定影响的．     

高放废物处置库近场剂量场与温度场的耦合计算

计算了高放废物处置库固化体内外的辐射剂量场,并将之作为热源叠加到温度场计算方程,使剂量场与温度场耦合起来.在温度场计算中,不仅考虑了固化体内存在的剂量场对其的影响,而且考虑了固化体外存在剂量场的影响.模拟结果表明,固化体外存在的剂量场对温度场是有一定影响的.     

电子束辐射对铜绿微囊藻蛋白质及抗氧化体系酶活性的影响

铜绿微囊藻以其毒素和产生的嗅味威胁人类健康和安全,且因大量生长和难去除性给水处理带来困难。本文以电子加速器产生的电子束对铜绿微囊藻培养液（对数生长期）分别进行1、2、3、4和5 kGy剂量的辐射,通过考察藻细胞蛋白质、抗氧化体系酶活性及光合速率的变化,研究辐射对铜绿微囊藻生命特征及机能产生的影响。结果表明：1 kGy的辐射对藻细胞可溶性蛋白质及POD、SOD活性的影响较小;而2～5 kGy的辐射明显降低了蛋白质含量,并破坏了藻细胞的抗氧化系统,光合速率也因辐射明显降低,使铜绿微囊藻短时间内失活。表明一定剂量的电子束辐射能有效控制藻细胞生长,并影响其重要生命特征。     

辐射加工工艺

本文讨论了辐射加工工艺学的定义,评述了它的主要领域(辐射消毒、辐射交联,电子束固化涂层、辐照食品、辐射处理三废和辐射在生物医学工程及材料科学中的应用)的进展与发展趋势,还对发展我国的辐射工艺提出了具体建议。     

辐射固化的国际现状——第一届亚洲地区国际辐射固化会议简介

辐射固化技术是辐射加工技术的分支,八十年代以来发展迅速,年增长率在10％以上。用辐射固化的产品种类很多,而磁性介质,隔离涂层,陶瓦瓷砖的装饰面,石膏板装饰表层、印刷板、光纤保护层,电子技术、蚀刻技术、压敏粘合剂等等。实现辐射固化首先要考虑好有关的化学问题。为发展辐射固化技术也应介绍UV/EB固化的安全操作、工业操作规程及专利法等,有关该领域的设备及工业获得很大的进展。     

固化氛围对丙烯酸酯紫外光固化材料表面性能的影响

在空气或氮气氛围下对同样配方的光敏树脂进行紫外光固化,固化膜的表面能测定表明,空气中固化材料的表面能大于氮气中固化材料.固化膜的元素分析和衰减全反射-傅立叶变换红外光谱(Attenuated total reflectance-Fourier transform infrared spectroscopy,ATR-FTIR)分析表明,氧阻聚反应并未导致空气下固化的材料中氧含量的明显变化,其红外谱图中未见有过氧基团的吸收峰,但其表面富集有较多的吸电子基团;而氮气下固化的材料表面存在较多的碳碳单键.X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)分析表明,不同的固化氛围使材料表面C1s和O1s原子结合能产生差异.说明固化氛围影响固化速率,使固化过程中固化膜组成分布或聚集态密度产生差异,最终使固化层的表面化学组成乃至表面能存在差别.     

叔胺结构对有机硅改性聚丙烯酸酯树脂UV固化的影响

UV-radiation curing has become a well-accepted technology because of its distinct advantages mainly as environmental benign, efficiency, less energy consumption and mild curing condition. The free radical photopolymerizations have been based mainly on acrylate systems, which polymerize rapidly and can be adjusted with ease to modify materials with different properties for different applications. The primary limiting factor of the approaches, however, is that the reactions would be inhibited by oxygen. A main method to tackle the problem is to add tertiary amine. Nevertheless, this causes new problems in the curing products, which turn yellow easily and their deposited period becomes short.In this work we have synthesized silicone modified polyacrylate (SPA) resins from bis[3-(trimethoxysilyl)propyl]amine (A1170) and polyethylene glycol diacrylate (SR-344) through Michael addition (Fig. 1). Without adding any extra tertiary amine, the structure of the obtained prepolymers could effectively solve the problem of oxygen inhibition.The DPC curves characterizing the UV curing behavior of the prepolymers are shown in Fig.2. With the SPA, the curing reaction in ambient atmosphere reached the maximum reaction rate at almost the same time as in N2, and the reaction rate in air is a little higher than in N2. The conversion of SPA in air is also a little higher than in N2. All these may be explained as follows. Tertiary amine can suppress the oxygen inhibition and produce more radicals. Tertiary amine may offer hydrogen to peroxide free radical produced in the oxygen inhibition process, the latter further decompose into alkyl radicals and hydroxide radicals.However, chain transfer and radicals terminations tend to occur, which made the rate reduced quiekly at later stages of the curing [1].     

Study on sensitized radiation polymerization of solid trioxane on pilot-scale

A conversion rate of more than 90% was obtained in sensitized polymerization, and the output of radiation was double at a reduced total dose of 0.5 Mrad as compared to original 1 Mrad.The unpolymerized monomer could be removed simply by extraction under reduced pressure to save a large volume of organic solvent. The quota of raw material consumption would be reduced without influencing quality of the product.experiments indicated that the content of water in trioxane, even up to 300 ppm, has no effect on conversion o molecular weight. Irradiated trioxane was stored in dry air kept away from light at room temperature could effectively sustain the lifetime of active species even after a lapse of one month.The infrared spectrum, molecular weight distribution and physical mechanical properties of the product from sensitized radiation polymerization were identical with those of the unsensitized process.     

高能电子束辐射对碳纤维表面结构的影响

利用激光拉曼光谱（Raman Spectroscopy）、X射线光电子能谱（XPS）、原子力显微镜（AFM）和X射线衍射（XRD）对高能电子束辐射前后的表面结构进行分析，结果表明，随着剂量的增加，碳纤维表面石墨微晶尺寸增大。碳原子在高能电子束的作用下离位，使表面棱角超于圆滑，当剂量较大时，处于石墨片层边缘的活性碳原子重新增多。碳纤维表面极性官能团受辐射介质产生的活性种的影响，同时在高能电子束辐射下激活，发生自淬灭反应和解离反应，前者占优势时，高价态的C＝O增多，反之，C－O基团增多。在试验范围内，高能电子束对碳纤维的晶型结构无影响。     

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。     

聚四氟乙烯膜辐射接枝反应条件的研究

采用了共辐射接枝技术，在室温下将苯乙烯接枝到聚四氟乙烯薄膜上，合成了辐射接枝膜。研究了溶剂种类、单体浓度、辐射剂量以及剂量率等因素对接枝反应的影响。结果表明，单体浓度和辐射剂量率是反应的主要影响因素，两者对接枝反应速率的影响指数分别为1．2和0．4。     

The Luminescence Decay Time of Air and Nitrogen-Oxygen Mixtures Excited by Alpha Particles

A systematic study of nitrogen luminescence decay time has been performed, exciting nitrogen by ? particles in various oxygen mixtures and air near atmospheric pressure. Results obtained by varying the oxygen ratio from 0 to 20% and total pressure from 200 to 2000 torr are given and explained by kinetic theory of the phenomena. It seems that a resonance collision process is responsible for the changes in the decay times of the second positive nitrogen group. An extrapolation of the measurements gives a decay time of 0.52 ns for air at atmospheric pressure. We proposed to study the luminescence decay time of air excited by the alpha particles of Polonium 210, in a pressure range between 200 and 2000 torr. As is known, nitrogen is mainly responsible for the luminescence of air irrespective of the excitation method; the most intense bands emitted correspond to transitions of the second positive system of the N2 molecule arn the first negative system of the once ionised molecule N2+5. Between 220 and 600 nm, the spectral domain of our experiments, the presence of oxygen is shown by a strong inhibition of the intensity of the nitrogen bands and by the appearance of the auroral line OI at 557.7 nm line, whose intensity is always very small. We therefore compared the luminescence decay time of the air and that of a mixture containing 80% nitrogen and 20% oxygen.