乙烯基硅树脂改性EVA胶膜的制备

以混合氯硅烷及硅氧烷为单体,采用水解共缩聚的方法制备了乙烯基硅树脂,并研究了合成该树脂的影响因素;以乙烯基硅树脂为改性剂,以高乙酸乙烯含量的乙烯-乙酸乙烯共聚物(EVA)为基体,通过熔融混炼法添加各种助剂,得到改性的EVA胶膜,探讨了乙烯基硅树脂对EVA胶膜性能的影响。结果表明:乙烯基硅树脂改性的EVA胶膜热稳定性和老化性能得到了提高;含有苯基的乙烯基硅树脂改性EVA胶膜时,所得胶膜的热氧老化性能好,透光率高,且黄色指数增大速率较慢。因此,含苯基乙烯基硅树脂是EVA胶膜的理想改进剂。     

太阳能电池用EVA封装胶膜的性能研究

以丙烯酸(AA)、甲基丙烯酸甲酯(MMA)、γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH-570)分别作为接枝单体,对EVA(乙烯-醋酸乙烯酯共聚物)进行接枝改性,着重探讨了接枝单体对EVA封装胶膜交联性能、粘接性能、透光性和耐湿热老化性能的影响。研究结果表明:KH-570接枝的EVA胶膜具有相对最好的综合性能,其凝胶率超过90%(即交联度较高)、剥离强度相对最大、1 mm厚EVA胶膜在波长为400~1 000 nm范围内的透光率超过85%且耐湿热老化性能良好。     

太阳能电池封装用EVA胶膜性能的研究

采用特殊结构的硅烷偶联剂对乙烯-乙酸乙烯酯共聚物(EVA)进行化学熔融接枝。利用硅烷接枝的EVA作为基础树脂,辅以复合引发剂、助交联剂以及各种老化助剂,经过热挤出成型制备出EVA胶膜母料。考察了复合引发剂用量对EVA胶膜交联度的影响,研究了硅烷接枝EVA和未接枝EVA胶膜的剥离强度及耐老化性能。结果表明:硅烷接枝EVA胶膜最佳的固化温度为160℃,最佳固化时间为11 min;硅烷接枝EVA具有良好的剥离强度、耐湿热和紫外光老化性能。     

层压型卡用带胶膜TPU胶层研究

初步研究不同用量的EVA树脂及纳米SiO2对带胶膜TPu胶层性能的影响,考察了材料的透光率、雾度、剥离强度、加速老化性能,实验结果表明：纳米SiO2用量的增加会降低带胶膜的透明性,而2．5％的用量不影响透明性,同时提高了综合性能;EVA树脂价格较低,能降低产品的成本,但粘接强度低,研究发现5％的用量能满足TPu胶层的性能。     

高反光率EVA胶膜的制备与性能研究

文章介绍了高反光率EVA胶膜的制备过程,并将其与常规EVA胶膜以及双玻组件用EVA胶膜进行封装组件功率及黄色指数变化效果对比分析。研究结果表明:采用高反射功能助剂改性方法制备的高反光率EVA胶膜,具有优异抗紫外辐射老化能力,同时能够提高组件的光电转换效率及功率。     

湿老化对丁羟推进剂力学性能的影响

为了研究湿老化对丁羟推进剂力学性能的影响,在10、30、50℃以及多种相对湿度条件下进行了丁羟推进剂的湿老化试验,对湿老化后的推进剂试样进行了力学性能测试,研究了温度在湿老化过程中的作用以及相对湿度对湿老化速度和力学性能下降程度的影响。结果表明,随着湿老化时间的增加,推进剂的力学性能逐渐下降;湿老化温度相同时,相对湿度越大相对抗拉强度的下降速度越快,下降程度也越大;相对湿度相近时,温度越高相对抗拉强度的下降速度越快。     

光伏组件用EVA封装胶膜的老化研究进展

综述了自上世纪80年代以来乙烯一醋酸乙烯酯共聚物（EVA）的老化机理及研究成果,介绍了光伏组件用EVA配方及结构对封装胶膜老化性能和使用寿命的影响。提出了光伏组件封装胶膜老化研究存在的问题。     

光伏组件封装EVA的湿热老化研究

对光伏组件封装EVA胶膜的湿热老化进行了研究,采用FT-IR法对湿热老化中的EVA进行测试和分析。实验结果表明,在湿热老化过程中,EVA发生了水解反应,产生乙酸,提高温度和相对湿度均会加快水解;EVA吸水率越高,越容易发生水解。     

有机转光剂在EVA光伏胶膜中的应用及耐老化性能研究

以EVA(乙烯-醋酸乙烯共聚物)为基体,通过引入适量的交联剂、抗氧剂和转光剂(即含饱和C—H键的有机转光剂O),制得转光型EVA光伏胶膜。研究结果表明:当w(有机转光剂O)=0.03%(相对于胶膜质量而言)、挤出机温度为95℃和胶膜厚度为(0.5±0.01)mm时,所得胶膜透明性良好(280~380 nm透光率占30.8%、380~1 100 nm透光率占92.5%)、对光伏发电功率增益较高(功率增益为0.67%)且耐UV黄变性较佳(经155℃层压25 min后,耐老化性符合光伏组件封装用EVA胶膜的国家标准)。     

发泡三元乙丙橡胶在热空气及湿热和盐雾环境下的老化机理研究

研究发泡三元乙丙橡胶（EPDM）在热空气、湿热及盐雾环境下的老化机理。结果表明：对于橡胶分子主链结构饱和的发泡EPDM,热空气、湿热及盐雾老化对其橡胶分子主链结构的破坏很小;热空气老化引起的二次交联可以增大发泡EPDM的交联密度,且温度越高,二次交联越剧烈,交联密度达到极值后,随老化时间的进一步延长,交联密度下降;湿热老化可以加速老化过程中发泡EPDM的二次交联,35 ℃盐雾老化对交联密度影响不大。     

农膜用聚乙烯树脂分子结构与耐老化性能的关系

通过对低密度聚乙烯（PE_LD）、线形低密度聚乙烯（PE-LLD）、茂金属线形低密度聚乙烯（m-PE—LLD）、乙烯-乙酸乙烯酯共聚物（EVA）等原料直接吹塑农用棚膜进行农田扣棚试验和力学性能测试，分析了各种树脂对生产PE功能性农用棚膜的适用性，并尝试从各种树脂基础分子结构角度对农膜的耐老化性能进行解释。试验结果表明：m—PE-LLD附脂的力学性能明显优于PE-LD和EVA树脂，EVA树脂在透明性方面占有优势；在耐老化性能方面，m-PE-LLD和EVA树脂无论扣棚时间还是测试数据均比PE-LD要好，从连续取样测试数据看出PE-LD断裂伸长保留率下降趋势明显，而m-PE-LLD和EVA树脂则是拉伸强度保留率下降趋势明显。     

Investigation of the photodegradation behaviors of an ethylene/vinyl acetate copolymer solar cell encapsulant and effects of antioxidants on the photostability of the material

This study concerns the photodegradation and stabilization of a solar cell encapsulating material made from ethylene/vinyl acetate copolymer (EVA). EVA was compounded with various additives in a twin‐screw extruder. After that, the extruded film was cured in a hydraulic compression mold before being exposed to ultraviolet (UV) radiation at an ambient temperature for 800 h. The thermal stability of the material was also studied through the aging of the sample at 90°C for 2000 h. The tensile strength of the unstabilized EVA decreased only slightly after the thermal aging. On the other hand, the strength of the material decreased noticeably after the UV irradiation. Fourier transform infrared spectra of various EVA films revealed that there was no deacetylation occurring after the UV irradiation. However, results from the swelling test and swollen‐state NMR suggested that the polymer degraded via a chain‐scission mechanism. After compounding with some antioxidants, most of the EVA films scarcely degraded after the UV irradiation, with the exception of the EVA compounded with a combination of the aromatic phosphate compound (0.1 phr) and hindered amine light stabilizer (0.1 phr). The results are discussed in light of an antagonism effect that occurred because of the aforementioned combination. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

EVA改性PE共混物力学性能和流变性能的研究

讨论了橡塑共混比、填料用量等因素对乙烯－醋酸乙烯共聚物（ＥＶＡ）改性ＰＥ共混物力学性能和流变性能的影响。试验结果表明，ＥＶＡ弹性体的加入降低了共混物的拉伸强度，提高了扯断伸长率及共混物熔体的流动性；活性碳酸钙的加入使共混物的拉伸强度、扯断伸长率和流动性下降；ＨＤＰＥ的加入提高了共混物的拉伸强度，但扯断伸长率和流动性下降。     

Effect of hot air aging on properties of EPDM/SmBO3/EVA and EPDM/ATO/EVA composites

Ethylene–propylene–diene rubber (EPDM)/samarium borate (SmBO₃)/ethylene‐vinyl acetate (EVA) copolymer and EPDM/antimony‐doped tin oxide (ATO)/EVA composites are aged at 150°C for different intervals. Surface modification is used to improve filler to matrix interphase. The main aim is to investigate the effect of filler type and vinyl acetate (VA) content in EVA on stability of EPDM composites. It is found that acidic ATO particles can lower pH level of EPDM composites and then promote the degradation of acetic acid during aging. Moreover, when VA content exceeds 14 wt %, the instable VA content causes more acetic acids escape during aging. With the increasing of aging time, EPDM/SmBO₃ control and EPDM/SmBO₃/EVA composites tend to become darker while EPDM/ATO and EPDM/ATO/EVA composites would become yellow. And the color change is correlated well with the variation of carbonyl index. The chemical crosslink points prevent crystals in EVA from melting at aging temperature (150°C), and the variation of crosslink density influences the crystallinity during aging. The tendency of tensile strength is well consistent with that of swelling ratios, and electric properties are correlated with increased polar groups and crystallinity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

超快固化高性能太阳能电池用EVA封装膜的研制

以33%VA(醋酸乙烯)含量的EVA(乙烯-醋酸乙烯共聚物)为聚合物基体,采用熔融共混法制成改性EVA母粒;然后采用流延成膜法制得C1(不含改性EVA胶粒的胶膜)和C2(含改性EVA胶粒的胶膜)。通过对比试验法探讨了不同EVA胶膜的交联度、剥离强度和耐老化性能。结果表明:C2的层压时间短、剥离强度高、耐老化性能较好,其各项性能与美国EVA胶膜接近,达到超快固化高性能EVA胶膜的使用要求,完全符合太阳能电池的封装条件。     

HDPE/PC/EVA共混体系的性能研究

研究了乙烯-醋酸乙烯共聚物(EVA)增容高密度聚乙烯(HDPE)和聚碳酸酯(PC)共混体系，讨论了EVA，PC对HDPE／PC共混合金性能的影响。结果表明：随PC用量的增加，HDPE／PC共混合金的熔体流动速率减小，缺口冲击强度增大，拉伸强度增大，维卡软化点变化不大。EVA能够改善合金体系的加工流动性，却明显降低了合金体系的力学性能。     

助交联剂在氢化丁腈橡胶中的应用研究

研究了添加不同用量的助交联剂齐聚酯和三甲基丙烯酸三羟甲基丙烷酯(TMPTMA)氢化丁腈橡胶的硫化特性、力学性能,并对比了两种助交联剂对氢化丁腈橡胶的硫化特性、力学性能、老化性能、高温拉伸性能、耐磨性能和加工性能的影响。结果表明：随着齐聚酯和TMPTMA含量的增加,橡胶的扭矩增大,硫化时间缩短;拉伸强度基本不变,硬度、100%定伸应力、撕裂强度逐渐提高,拉断伸长率、回弹性减小。与添加齐聚酯的橡胶相比,添加TMPTMA橡胶的扭矩较大,硫化时间较短;对比添加齐聚酯和TMPTMA的橡胶,它们的力学性能、老化性能、高温拉伸性能和耐磨性能都非常接近,可见它们在硫化过程中的作用原理相似。由橡胶加工分析仪可知,添加TMPTMA橡胶的储能模量较小,损耗因子较大。     

Poly(methyl methacrylate) toughened by ethylene‐vinyl acetate copolymer: Physico‐mechanical,thermal, and chemical properties

Blends of poly(methyl methacrylate) (PMMA) with different composition viz., 5, 10, 15, and 20 wt % of ethylene‐vinyl acetate (EVA) copolymer were prepared by extrusion in a corotating twin screw extruder. These prepared PMMA/EVA blends have been characterized for physicomechanical properties such as density, surface hardness, izod impact strength, tensile strength, tensile elongation, and tensile modulus. The chemical aging and heat aging tests were performed on the blends by exposing them to different chemical environments and to 80°C for 168 h respectively. The influence of chemical aging and heat ageing on the mechanical performance of PMMA/EVA blends has been studied. The PMMA/EVA blends were also characterized for thermal properties such as vicat softening point (VSP) and melt flow index (MFI). That means significant improvement in impact strength of PMMA was noticed after incorporation of EVA into PMMA matrix and it lies in the range 19.1–31.96 J/m. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Cold Plasma Modification Effects on the Water Flow through Sintered UHMWPE Membranes

Natural rubber latex and various concentration of natural antioxidant were blended in different ratios and irradiated at various absorbed doses by gamma rays from Co-60 source at room temperature. The aqueous extraction of Diospyros peregrina was used as natural antioxidant. It was found that the addition of different concentration of natural antioxidant into natural rubber latex improve the aging property of the film. Decreasing in tensile strength of rubber film with 10 phr natural antioxidant and 15 kGy radiation dose after 24 hours aging at 100°C was 9.34% compared to 13.89% for film without natural antioxidant. The tensile strength, tear resistance and modulus at 500% elongation of the rubber film were found to be optimum at 15 kGy radiation dose and with 10 phr natural antioxidant. Elongation at break, permanent set and swelling ratio decreases with the increasing absorbed radiation dose as well as the concentration of the natural antioxidant.