光伏EVA封装胶膜交联体系的研究

主要研究了光伏组件用EVA封装胶膜的交联体系。通过对EVA封装胶膜硫化曲线的分析,研究了EVA胶膜中交联剂、助交联剂、硅烷偶联剂的含量对胶膜硫化曲线的影响,并推断出交联剂、助交联剂及硅烷偶联剂对EVA胶膜交联性能的影响。实验证明通过调整上述3个助剂的含量能够实现对EVA胶膜交联能力的控制。     

太阳能EVA封装胶膜

<正>广州鹿山新材料股份有限公司的太阳能电池用EVA封装胶膜产品,是针对目前国内EVA胶膜在长期耐候性、耐黄变性以及产品适应性等方面与进口产品差异较大的实际情况,通过对太阳能电池用关键材料     

首诺EVA封装胶膜在中国正式投产

2011年5月4日,首诺公司宣布,正式启动其位于中国苏州的全新Vistasolar乙烯-醋酸乙烯酯共聚物(EVA)封装胶膜生产中心。近日,该中心通过了多项具有里程碑意义的测试,用于太阳能模块的Vistasolar EVA封装胶膜的商业化生产已     

首诺EVA封装胶膜在中国正式投产

<正>2011年5月4日首诺公司宣布,正式启动其位于中国苏州的全新乙烯-醋酸乙烯酯共聚物(EVA)封装胶膜生产中心。近日,该中心通过了多项具有里程碑意义的测试,用于太阳能模块的EVA封装胶膜的商业     

首诺EVA封装胶膜在中国正式投产

5月4日,首诺公司正式启动其位于中国苏州的全新Vistasolar乙烯-醋酸乙烯酯共聚物(EVA)封装胶膜生产中心。该中心通过了多项具有里程碑意义的测试,用于太阳能模块的Vistasolar EVA封装胶膜的商业化生产已全面就绪。     

首诺EVA封装胶膜中国生产中心即将竣工

2011年2月21日首诺公司宣布乙烯-醋酸乙烯共聚物(EVA)太阳能电池封装胶膜中国生产中心的主要工程已建设完成。Vistasolar乙烯-醋酸乙烯共聚物(EVA)封装胶膜预计于2011年3月投入批量试生产,成品将于第二季度上市。这是首诺在收购德国Etimex太阳能公司之后建成的第一家EVA封装胶膜生产线,其位于中国苏州的首孚信聚乙烯醇缩丁醛(PVB)中间     

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。     

光伏背板粘结涂层与封装胶膜粘结力的研究

光伏背板粘结涂层与封装胶膜乙烯醋酸乙烯酯（ EVA）的粘结力是决定组件封装效果的关键因素。通过考察 EVA胶膜的种类、放置时间,以及涂料配方中氟碳树脂与丙烯酸树脂的质量比、填料的类型和含量、涂层厚度对涂层与 EVA胶膜粘结力的影响,结果发现通用型透明胶膜、抗蜗牛纹的胶膜与涂层的粘结力优于抗电位诱导衰减（ PID）功能的胶膜,胶膜的放置时间越长,与涂层的粘结力越低;涂料中丙烯酸树脂的添加会增大涂层与 EVA的粘结力,消光粉的表面有机处理、填料增多均会降低涂层与 EVA的粘结力;涂层的厚度越厚,与 EVA的粘结力越高。     

光伏组件用EVA封装胶膜的性能研究

文章研究了EVA封装胶膜的交联体系、粘结性能和透光性能。研究实验表明:交联剂含量0.5%和助交联剂含量0.6%时,EVA胶膜的交联度最高,同时添加剂的用量也最经济;粘结性能随KBM-503含量的增加而增强,最后达到趋于稳定;添加不同的助剂满足组件上下两层EVA胶膜不同的透光率要求。     

专利介绍

<正>薄膜太阳能电池封装用非交联型EVA胶膜CN103 555 214(2014-02-05)。该胶膜(以质量分数计)由乙烯-醋酸乙烯共聚物97%~98%、马来酸酐1.2%、硅烷偶联剂0.4%、光稳定剂0.1%~0.2%、过氧化二异丙苯0.05%~0.06%和抗氧剂0.1%~0.3%等组成。该胶膜具有较高的熔点和强度、较低的流动性和较强的粘接力,并可保持热塑性状态,而且可采用辊压工艺实现薄膜太阳能电池组件的连续封装生产,具有更高的封装效率和较低的成本。     

酰胺化纳米晶纤维素提高乙烯-醋酸乙烯酯共聚物薄膜阻透性的研究

合成了三种酰胺化纳米晶纤维素,并采用溶液共混成膜法制备了酰胺化纳米晶纤维素（CNC）/乙烯醋酸乙烯醋共聚物(EVA)复合膜材料。通过紫外-可见分光光度计、电子万能试验机和透湿仪研究了酰胺化CNC/ EVA复合膜的光学性能、力学性能以及水蒸气阻隔性,并通过原子力显微镜研究热压处理的EVA复合膜的表面形貌。结果表明,添加三种不同碳链的酰胺化CNC都使 EVA膜的透光率有所降低,当添加量为5 %时,EVA膜透光率仍高达90%。一定程度的热压能够让酰胺化纳米晶纤维素在EVA基体中分散更均匀,使EVA复合膜的透光率提高了2%～3%;随着纳米晶纤维素含量的逐渐增加,三种酰胺化CNC/EVA膜的拉伸强度均逐渐增强,透湿率（WVTR值）均减小;酰胺化CNC含量相同时, 十六胺改性的纳米晶纤维素(CNC-N16)/EVA复合膜的力学性能和水蒸气阻隔效果优于相应的十二胺和正辛胺。     

Thermal and physicomechanical properties of ethylene-vinyl acetate copolymer and layered double hydroxide composites

A series of ethylene-vinyl acetate (EVA) copolymer films have been prepared with different compositions viz. 2, 4, 6, and 8 wt % layered double hydroxide (LDH) nanoparticles by solution intercalation method. These solution-casted EVA/LDH nanocomposite films were dried and characterized by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. EVA/LDH films were further tested for tensile strength, density, moisture content, solubility resistance, flammability, and electrical properties. The DSC and FTIR analysis indicate strong interactions between the LDH layers and vinyl acetate groups in EVA. Further, EVA nanocomposite films show enhanced tensile strength, limiting oxygen index (LOI), and flammability rating for the addition of LDH without sacrificing the electrical properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Photodegradation and biodegradation by bacteria of mulching films based on ethylene‐vinyl acetate copolymer: Effect of pro‐oxidant additives

The photodegradation (432 h under irradiation of Xe‐Lamp‐solar filter) of an ethylene vinyl acetate (EVA) copolymer with vinyl acetate content of 9% was studied, and the effect of iron and calcium stearates was evaluated using different techniques such us attenuated total reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR), gel permeation chromatography (GPC), and thermal analysis methods (DSC and TGA). A re‐arrangement in crystallization and consequent decrease in thermal stability were found through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), which were in agreement with the chain scission tendency. The presence of Ca and Fe pro‐oxidants additives in EVA films increased the ketone carbonyl formation and decreased the ester absorption band of the acetate respect to the pure EVA, as it was evidenced by the significant changes in Carbonyl Indexes found by FTIR. The activity of stearates has been also evaluated by chemiluminescence, where the temperature‐ramping tests under nitrogen showed the formation of a peroxide peak at lower temperature. The lower stability of the films containing pro‐oxidants was evidenced by the values of oxidation induction time (OIT) determined by DSC. The results were supported by GC‐MS, where the concentration of extracted products identified in the EVA containing pro‐oxidants was significant and a much greater decrease in molecular weight was determined by GPC, which confirmed the development of degradation for EVA with Ca and Fe stearates in comparison to pure EVA. Biodegradation of photodegraded EVA films were studied at 45°C during 90 days using a mixture of Bacillus (MIX) (B. cereus, B. megaterium, and B. subtilis) and, in parallel, by Brevibacillus borstelensis as reference strain. Biodegradation of EVA‐films was studied by Chemiluminescence, ATR‐FTIR and GC‐product analysis and the data confirm more efficient biodegradation on the materials containing pro‐oxidants. The chemiluminescence emissions due to decomposition of oxidation species was observed at lower temperatures on the biodegraded samples. Also, the drastic decrease of carbonyl index and the disappearance of photogenerated low molecular products with biodegradation were more efficient on the biodegraded films containing pro‐oxidants. EVA mineralization was evaluated by carbon dioxide measurement using indirect impedance technique. Biodegradation by B. borstelensis and MIX at 45°C was similar and exhibited a pronounced difference between the pure photodegraded EVA film (around 15% of mineralization) and the corresponding photodegraded films containing Ca and Fe stearates where biodegradation extent reached values of 23‐26% of biodegradation after 90 days. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of vinyl acetate content on the photovoltaic-encapsulation performance of ethylene vinyl acetate under accelerated ultra-violet aging

The vinyl acetate (VA) content in ethylene vinyl acetate (EVA) can significantly affect its performance as an encapsulant in photovoltaic modules under field conditions. EVA films of varying VA content (18, 24, 33, and 40%) have been prepared using twin screw extruder with the necessary additives and subsequently cured at 150 °C. All the EVA films have been subjected to UV radiation at a wavelength of 340 nm for 1000 and 2000 h to simulate accelerated field aging. The effects of accelerated aging on the gel content, mechanical properties, transmittance, Fourier transform infra-red (FTIR) spectra, thermal stability, degree of crystallinity, and yellowness have been studied. The observations made in this study of UV aging up to 2000 h suggests that the optimum range of VA content in EVA should be between 18 and 33% by weight. VA content beyond 40% degrades almost all properties needed for an encapsulate material after aging of only 2000 h. VA content of around 18% is the most stable under UV aging conditions but has a slightly lower value of transmittance for the unaged sample although the difference in transmittance between different specimens decreases with UV aging. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48268.     

Stress relaxation in low‐shrink‐force polyolefin films

The morphology and stress relaxation of coextruded five‐layer LLDPE (linear low‐density polyethylene)/EVA (ethylene‐vinyl‐acetate) copolymer films were studied. Increasing VA (vinyl acetate) content in EVA causes a decrease of shrink tension in the films, which can be explained by a decrease in amount of crystallinity. The relaxation time spectrum of the coextruded crosslinked LLDPE/EVA films is similar to the relaxation time spectrum of crosslinked LLDPE film at room temperature. However, at elevated temperatures, an additional peak appears on the spectrum of coextruded film. The cause of this peak is temperature‐ and stress‐induced recrystallization of EVA during the relaxation test. This recrystallization was confirmed with DSC and wide angle X‐ray analysis. Polym. Eng. Sci. 44:1716–1720, 2004. © 2004 Society of Plastics Engineers.     

Transfer of a low-molecular-weight compound between two immiscible polymers

We investigated plasticizer transfer between poly(ethylene-co-vinyl acetate) (EVA) and poly(lactic acid) (PLA) and its temperature dependence using laminated films comprising EVA and PLA, each containing equal amounts of a plasticizer [i.e., diethyl phthalate (DEP) or dibutyl phthalate (DBP)]. Because the miscibility between PLA and DEP is better than that between EVA and DEP, a large amount of DEP was detected in the PLA film after annealing the laminated films at 80 °C; that is, some DEP moved from the EVA film to the PLA film. Furthermore, more DEP migrated to the PLA film at 130 °C, suggesting that the difference in the interaction parameter with DEP between PLA and EVA is more pronounced at higher temperatures. In laminated films containing DBP, the DBP content in each film was almost equal after annealing at 80 °C, although DBP migrated from the PLA film to the EVA film at 130 °C. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47386.     

Effects of preparation conditions on the morphology and gas permeation properties of polyethylene (PE) and ethylene vinyl acetate (EVA) films

In this study, the effect of film preparation conditions on the gas permeation properties of polyethylene (PE) and ethylene vinyl acetate (EVA) films (containing 18 and 28 wt% vinyl acetate) was investigated. Film blowing and phase inversion methods were applied in the production of PE and EVA films, respectively. The permeation of pure oxygen and carbon dioxide gases was measured at room temperature. The results indicated that with the increase of PE film thickness, permeability and solubility of O₂ and CO₂ in these films decreased; but the diffusivities of gases through PE films increased. In addition, in the case of EVA copolymers, by increasing the content of vinyl acetate, the permeability of CO₂ increased. The rate of increase in CO₂ permeability was different for samples having different preparation conditions. For example, the samples prepared using chloroform as the solvent instead of THF, showed lower CO₂ permeability. Also, the morphological studying of film structure indicated that the higher CO₂ permeability for the samples made from THF solvent is due to the existing of higher porosity in the under layer polymer area. Also scanning electron microscopy (SEM) micrographs showed that with the usage of phase inversion method, there will be a thin dense layer near to the glass substrate.     

木质素填充LDPE、EVA对复合物性能的影响

以木质素为填充剂分别与低密度聚乙烯(LDPE)、乙烯-乙酸乙烯酯共聚物(EVA)共混,经双螺杆造粒机共混挤出造粒,再经吹塑成膜。研究了木质素/LDPE、木质素/EVA共混物薄膜的表面形貌、力学性能、热性能和红外光谱。热分析表明木质素与EVA共混物的热稳定性比木质素与LDPE的共混物热稳定性好;红外光谱分析表明木质素与EVA分子间产生了强烈的相互作用,扫描电镜分析表明木质素与EVA共混的相容性较好,力学性能分析表明低于30%的木质素与LDPE、EVA共混力学性能较好。     

Thermal and mechanical characterization of EVA/banana fiber-derived cellulose composites

Composite films based on poly(ethylene-co-vinyl acetate) (EVA) and cellulose derived from banana plant waste have been prepared and characterized. Cellulose whiskers isolated from, banana fibers, by an acid hydrolysis method and were incorporated into the EVA matrix by solution casting technique. The composite films were subsequently examined by scanning electron microscopy, thermogravimetry, differential scanning calorimetry, and FTIR spectroscopy. Compared with pure EVA and cellulose, the EVA/cellulose composite systems showed superior thermal stability. The mechanical testing of the composite films revealed that the tensile strength and elastic modulus were increased after cellulose incorporation into EVA. Among the EVA/cellulose composites, 7.5% cellulose loaded EVA showed the highest tensile strength. The percentage strain at break of the EVA/cellulose composite systems was found to be decreased which has been attributed to the restricted mobility of the polymer matrix by the presence of cellulose. X-ray diffraction studies showed that the EVA/cellulose composites were more crystalline than EVA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation of Ethylene Vinyl Acetate Copolymer/Graphene Oxide Nanocomposite Films via Solution Casting Method and Determination of the Mechanical Properties

Ethylene vinyl acetate/graphene oxide (EVA/GO) nanocomposite films were prepared via solution casting method. The morphological studies investigated using SEM and XRD methods and the results confirmed the formation of likely exfoliation structures and good interaction between matrix and fillers. The results of permeability measurements showed that films have good resistance against oxygen. Mechanical measurements revealed that Young’s modulus and tensile strength of EVA have improved with introducing GO because of proper dispersion of GO into matrix and good interaction between them; however, elongation at break decreased due to formation of strong and rigid polymer/filler network preventing to elongate polymer chains.