国内外EVA树脂的生产技术及市场对比

介绍了乙烯一醋酸乙烯酯共聚树脂（EVA树脂）的生产工艺，分析了我国EVA树脂的生产消费现状及发展前景，提出今后的发展建议。     

薄膜级EVA树脂的市场分析

综述了我国薄膜级乙烯-乙酸乙烯共聚物(EVA)树脂的生产、应用以及2006年大陆地区EVA树脂的进口情况,分析了2006年我国薄膜市场中EVA树脂的消费情况.针对EVA棚膜较大的利润空间及市场需求,建议我国加强开发系列化EVA树脂以满足农用膜和包装膜的需求.     

EVA树脂发展急需快马加鞭

近10年来我国EVA树脂产品只有北京东方石油化工有限公司一家企业生产，但前不久传出消息，扬子石化-巴斯夫有限责任公司20万吨／年EVA树脂生产装置已进入试车阶段。其正式投产后将打破我国EVA树脂生产“一枝独秀”的局面，呈现“双梅争艳”之势。     

中国EVA塑料制品业的现状与发展

<正>EVA树脂(EVA塑料)是塑料行业重要的组成部分。我国EVA塑料在上个世纪70年代起步(EVA乳液的开发利用),经历了LDPE装置提供EVA塑料初始阶段,到90年代形     

我国乙烯-醋酸乙烯树脂的市场分析

分析了我国乙烯-醋酸乙烯(EVA)树脂的生产消费现状及发展前景。2017年我国EVA树脂的生产能力为97.2万吨,消费量为149.0万吨。预计2022年生产能力将达到约200.0万吨。提出了我国EVA树脂行业今后的发展趋势及发展建议。     

硼酸锌协同膨胀型阻燃剂改性电缆用EVA复合材料的制备与性能

为了改善电缆用乙烯-醋酸乙烯酯共聚物(EVA)的阻燃性能，通过掺杂硼酸锌(ZB)和膨胀型阻燃剂(IFR)，制备了EVA改性复合材料。结果表明：EVA中ZB掺杂量为15份时，制备的复合材料综合性能最优。EVA/ZB-15复合材料的拉伸强度为21.4 MPa，与EVA相比提高了35.4%。EVA/ZB-15复合材料的极限氧指数(LOI)为28.6%，达到UL94 V-0等级。EVA/ZB-15复合材料的热释放速率峰值为272 kW/m²，与EVA相比降低了32.2%；总热释放量为103 MJ/m²，与EVA相比降低了29.9%；产烟总量为15.6 m²，与EVA相比下降了39.1%,EVA复合材料具有较好的阻燃效果。     

乙烯—醋酸乙烯酸共聚物对茂金属聚乙烯的改性研究

以添加不同比例的茂金属聚乙烯（mLLDPE）/乙烯-醋酸乙烯酯（EVA）共混物为研究对象，考察了EVA含量对mLLDPE/EVA共混物的力学性能，热性能，流变性能，动态力学性能和形态结构的影响，研究结果表明，EVA添加到mLLDPE中，增加了mLLDPE的剪切敏感度，降低了mLLDPE的熔融粘度，改善了mLLDPE的流动性和加工性，在一定的添加比例范围内mLLDPE和EVA具有很好的相容性，可以在改善mLLDPE加工性能，引入极性基团的同时又保持与纯mLLDPE相近的力学性能，但会导致共混物材料的刚性下降，柔性增加，热分析数据说明，mLLDPE/EVA共混体系中，在EVA含量较小时共混物存在大量共晶，与mLLDPE有很好的相容性，无论是熔融曲线还是降温曲线都只出现一个峰，当EVA含量增大时，mLLDPE/EVA共混物出现相分离，曲线出现双峰，但两峰值呈现靠近趋势，预示mLLDPE/EVA共混物中仍存在少量共结晶。     

LDPE/EVA/Mg(OH)2阻燃复合材料流变行为的研究

借助HAAKE RHEOCORD 90流变仪分别在140℃、160℃、和180℃3个温度下，研究了LDPE／EVA和LDPE／EVA／Mg(OH)2阻燃复合材料的流变行为。研究结果表明：LDPE／EVA／Mg(OH)2阻燃复合材料的熔体流动行为同LDPE／EVA一样，仍属于非牛顿型假塑性流体流动行为。不同剪切速率下，LDPE／EVA／Mg(OH)2阻燃复合材料与LDPE／EVA粘流活化能相差很小，说明LDPE／EVA／Mg(OH)2阻燃复合材料与LDPE／EVA一样，其熔体粘度对温度不十分敏感。相同温度下，LDPE／EVA／Mg(OH）2阻燃复合材料的挤出膨胀比低于LDPE／EVA，这一特性说明LDPE／EVA／Mg(OH)2阻燃复合材料制品尺寸稳定性较LDPE／EVA有所提高。     

中国EVA树脂市场分析及发展建议

介绍了乙烯-乙酸乙烯酯共聚物(EVA树脂)的主要性能、应用领域以及主要生产工艺。分析了2015—2020年我国EVA树脂的产能、产量、进出口量以及消费量情况,总结梳理了“十四五”期间我国EVA树脂新增产能情况,同时预测了市场供需情况。预计到2025年,我国EVA树脂产能将达到4 300 kt,产量约为2 200 kt,消费量2 840 kt。针对我国EVA树脂产业面临的低端产品过剩、产品同质化严重、高端产品依赖进口等主要问题,从新增产能、产品研发、生产技术、产业布局四方面提出相关发展建议。     

PVC/EVA共混物的研究

中国科学院化学所对PVC与EVA共混物的性能进行了研究。该所用醋酸乙烯含量48％的EVA与PVC进行共混的动力学和微观性能研究表明，PVC与EVA共混物中存在的半相容性。当EVA体积含量18％～80％时，共混物的性能随EVA含量增加而变化；当EVA含量6％“8％时，共混物的抗冲击强度改进最为明显。PVC/EVA共混物的研究     

PVC抗冲改性剂的发展现状与研究进展

综述了我国聚氯乙烯（PVC）抗冲改性剂——聚丙烯酸酯类（ACR）、氯化聚乙烯（CPE）、甲基丙烯酸甲酯-丁二烯-苯乙烯三元接枝共聚物（MBS）、丙烯腈-丁二烯-苯乙烯共聚物（ABS）、乙烯-乙酸乙烯共聚物（EVA）、乙丙橡胶（EPR）的生产、市场需求情况及研究进展。     

塑料密度温度系数的测定

对HDPE、LDPE、PP、PS、ABS、EVA、PVC等常见塑胶粒的密度温度系数进行了测定。采用本文所测得的密度温度系数值,将常温下测得的密度值校正到指定温度下的密度值,这种方法可以满足塑料密度常规检验的要求。     

Morphological and mechanical properties of polypropylene [PP]/poly(ethylene vinyl acetate) [EVA] blends. II: Polypropylene‐(ethylene‐propylene) heterophasic copolymer [PP‐EP]/EVA systems

Morphological characteristics and mechanical properties of PP‐EP/EVA blends were studied and compared to those of PP/EVA previously reported. For the PPEP/EVA blends, interfacial interactions in amorphous zones, which were associated with shifts in T_g, were well defined compared to those of PP/EVA blends, although the nature of crystalline zones was similar for both systems. At EVA concentrations up to 20%, the elongation at break and impact strength slightly increased in both systems. However, PP‐EP/EVA displayed higher values of these properties compared with PP/EVA. At high EVA concentrations (above 20%), the indicated properties were enhanced in both polymeric systems, and the same proportional behavior was maintained. The decrease in tensile strength of PP‐EP/EVA was not as marked as in PP/EVA with the addition of EVA, and it remained below PP/EVA at high EVA concentrations. The improvement in properties of PP‐EP/EVA was attributed to favorable interactions between the ethylene groups contained in both copolymers. These interactions rendered a high degree of compatibility between the PP‐EP and EVA components.     

烟用包装胶的应用现状及发展前景

介绍了烟用包装胶的粘接特性。从烟用包装胶的上机适应性及生物安全性角度出发,对目前国内PVAc(聚醋酸乙烯)乳液胶粘剂、EVA(乙烯-醋酸乙烯共聚物)热熔胶等高速包装胶的研究发展状况、卷烟企业对包装胶的实际需求、包装胶存在的问题以及发展趋势等内容进行了讨论。     

Viscoelastic and adhesion properties of hot-melts made with blends of ethylene-co-n-butyl acrylate (EBA) and ethylene-co-vinyl acetate (EVA) copolymers

Several hot-melts (HMAs) were prepared by using blends of ethylene-co-n-butyl acrylate (EBA) and ethylene-co-vinyl acetate (EVA) copolymers - EBA/EVA. HMAs were prepared with mixtures of EVA copolymers with 18 (EVA18) and 27 (EVA27) wt% vinyl acetate contents and EBA copolymer with 27 wt% n-butyl acrylate, polyterpene resin and mixture of microcrystalline and Fischer-Tropsch waxes. HMAs made with EBA/EVA blends showed lower viscosities and reduced shear thinning than the ones made with EBA or EVA due to differences in compatibility, but both the set time and the open time were not affected as they depended mainly on the wax nature and amount. The increase of the vinyl acetate (VA) content in EVA copolymer reduced the crystallinity of the EBA/EVA blends. Even EBA copolymer was more compatible with EVA27 than with EVA18 (the α- and β-transitions shown in DMTA plots were closer) and the compatibility did not vary with the EBA content in the blends. The addition of polyterpene resin and the mixture of waxes decreased the compatibility of the EBA/EVA blends, the higher compatibility was observed for the HMAs made with only one copolymer. The tack of the HMAs depended on their EBA/EVA contents, EBA/EVA27 HMAs showed broader temperature interval with higher tack, while the tack of EBA/EVA18 HMAs blend decreased and the temperature interval with tack was shortened and shifted to lower temperatures. Adhesion to polypropylene film was improved in HMAs made with 75 wt% EBA/25 wt% EVA18 and 50–75 wt% EBA/50-25 wt% EVA27. The adhesion to aluminum film of EBA or EVA hot melts was improved only in the joints made with EBA/EVA 27 HMAs, more noticeably when they contained higher EBA content.     

Effect of vinyl acetate content on the mechanical and thermal properties of ethylene vinyl acetate/MgAl layered double hydroxide nanocomposites

Ethylene vinyl acetate (EVA)/Mg‐Al layered double hydroxide (LDH) nanocomposites using EVA of different vinyl acetate contents (EVA‐18 and EVA‐45) have been prepared by solution blending method. X‐ray diffraction and transmission electron microscopic studies of nanocomposites clearly indicate the formation of exfoliated/intercalated structure for EVA‐18 and completely delaminated structure for EVA‐45. Though EVA‐18 nanocomposites do not show significant improvement in mechanical properties, EVA‐45 nanocomposites with 5 wt % DS‐LDH content results in tensile strength and elongation at break to be 25% and 7.5% higher compared to neat EVA‐45. The data from thermogravimetric analysis show that the nanocomposites of EVA‐18 and EVA‐45 have ≈10°C higher thermal decomposition temperature compared to neat EVA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Rheology, Morphology and Estimation of Interfacial Tension of LDPE/EVA and HDPE/EVA Blends

Summary Rheological characteristics and morphology of low-density polyethylene (LDPE) /ethylene vinyl acetate copolymer (EVA) and high-density polyethylene (HDPE)/EVA blends were compared. Morphological examinations clearly reveal a two-phase morphology in which the LDPE/EVA blends have smaller dispersed domain size than HDPE/EVA Furthermore, LDPE/EVA shows a finely interconnected morphology at 50wt% of EVA while HDPE/EVA exhibits a coarse co-continuous morphology at the same composition. The morphological observations can be attributed to the lower viscosity ratio and lower interfacial tension in the LDPE/EVA system. The Palierne model also successfully fits to the experimental data giving higher values for interfacial tension of HDPE/EVA system as compared to LDPE/EVA.     

Radiation effects on LDPE/EVA blends

Radiation effects of low‐density polyethylene/ethylene‐vinyl acetate copolymer (LDPE/EVA) blends were discussed. EVA content in the LDPE/EVA blends was an enhancement effect on radiation crosslinking of LDPE/EVA blends, and the highest radiation crosslinking was obtained when the EVA content was reached at 30% when irradiated by γ‐ray in air. The phenomenon was discussed with the compatibility, morphology, and thermal properties of LDPE/EVA blends and found that the enhanced radiation crosslinking of the LDPE/EVA blends was proportional to the good compatibility, the increasing degree of the amorphous region's content of the LDPE/EVA blends, and the vinyl acetate content of EVA. We also found that the vinyl acetate of EVA in the blends is easily oxidized by γ‐ray irradiation in air. The possible radiation crosslinking and degradation mechanism of LDPE/EVA blends was discussed quantitatively with a novel method “step‐analysis” process of irradiated LDPE/EVA blends in the thermal gravimetric analysis (TGA) technique. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1296–1302, 2002     

Radiation effects on HDPE/EVA blends

In this article, we discuss the radiation effects of high‐density polyethylene (HDPE)/ethylene–vinyl acetate (EVA) copolymer blends. In comparison with the low‐density polyethylene/EVA blends, the EVA content in the HDPE/EVA blends had a lower enhancement effect on radiation crosslinking by γ‐ray irradiation in air. The phenomenon is discussed with the compatibility, morphology, and thermal properties of HDPE/EVA blends. The HDPE/EVA blends were partly compatible in the amorphous region, and radiation crosslinking of the HDPE/EVA blend was less significant, although increasing the amorphous region's content of the HDPE/EVA blends and the vinyl acetate content of EVA were beneficial to radiation crosslinking. The good compatibility was a prerequisite for the enhancement effect of EVA on the radiation crosslinking of the polyethylene/EVA copolymer. The radiation crosslinking and the degradation mechanism of HDPE/EVA blends were examined quantitatively by a novel method, the step analysis process of irradiated HDPE/EVA blends with a thermal gravimetric analysis technique. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 553–558, 2002