共查询到19条相似文献,搜索用时 171 毫秒
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紫外光辐射接枝及胺化法制备温敏性聚乙烯薄膜 总被引:1,自引:0,他引:1
实验探索在水性体系中经紫外光辐射,引发丙烯酸(AAC)在聚乙烯(PE)薄膜表面接枝,并经过胺化反应,在已改性的丙烯酸-聚乙烯(AAC-g-PE)薄膜上继续引入功能团,使改性后的PE薄膜具有温度敏感性。考察了引发剂用量、紫外光照射时间对接枝率的影响,并对不同胺化剂合成产物的温敏效应进行比较,从而达到实验目的。通过红外光谱和尺寸变化率证明丙烯酸接枝在PE表面,胺化反应后,生成聚N-异丙基丙烯酰胺聚合聚乙烯(PNIAAm-g-PE)薄膜和聚N-正丙基丙烯酰胺聚乙烯(NNPA-g-PE)薄膜具有温敏性。 相似文献
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LLDPE/LLDPE-g-AA共混物的接触角及红外光谱表征 总被引:2,自引:0,他引:2
利用溶融共混的方法制备了线性低密度聚乙烯/线性低密度聚乙烯接枝丙烯酸(LLDPE/LLDPE-g-AA)共混物。用傅里叶红外光谱(FT-IR)和测定接触角的方法对不同LLDPE-g-AA含量的LLDPE/LLDPE-g-AA共混物膜的表面进行了表征。结果表明,随着共混物中LLDPE-g-AA含量的增加,水和甘油等极性液体与共混物表面的接触角下降。依据共混物的FT-IR计算了其羧基峰强度。发现极性液体与LLDPE/LLDPE-g-AA共混物膜表面的接触角越小,羧基峰强度越大。 相似文献
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旨在对低密度聚乙烯蜡进行化学接枝改性,改善其可乳化性能,从而制备高稳定性改性聚乙烯蜡微乳液。首先以丙烯酸作为接枝单体,采用悬浮溶胀接枝法对低密度聚乙烯蜡进行化学接枝改性;然后,通过选取适当的阴离子乳化剂和非离子乳化剂的复配体系,对接枝改性的聚乙烯蜡产物进行乳化。结果表明:采用SDS和Tween80等比例复配,控制乳化温度为90~95℃,乳化剂用量为聚乙烯蜡的10%、乳化时间为30min时,采用相转变乳化法可制得高稳定性的聚乙烯蜡微乳液。采用FTIR对改性聚乙烯蜡进行了结构表征,证明了丙烯酸被成功地接枝到了聚乙烯蜡分子上,并通过DSC分析研究了其熔点和结晶情况的变化:聚乙烯蜡的熔点为102.41℃,丙烯酸接枝改性聚乙烯蜡的熔点为102.85℃;改性聚乙烯蜡与未改性的聚乙烯蜡的比结晶度为77.7%。 相似文献
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本文系统研究了不同条件(树形分子代数、浓度、浸泡时间等)下荧光性聚酰胺-胺树形分子(PAMAM)水溶液作为荧光探针对锡纸、透明胶带等基底上油印潜指纹的显现效果.结果发现PAMAM树形分子可以和指纹残留物进行靶向结合.结合到指纹纹线上的该荧光性纳米材料在暗室中365 nm紫外光的激发下发出明亮的蓝色荧光,指印纹线与基底反差大、指纹易于辨认,且操作简单,试剂完全环保无污染.这些结果表明PAMAM水溶液是一种潜在的优良的指纹显现试剂.最后,把PAMAM树形分子水溶液对指纹的显现效果进行量化处理,乳突纹与基底间的灰度对比度达到90%以上. 相似文献
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利用等离子体引发的接枝反应对低密度聚乙烯(LDPE)薄膜进行表面改性处理,通过对接枝单体后LDPE薄膜表面单体接枝率的计算和表面接触角以及表面自由能的测量,系统地研究了单体浓度、反应温度、处理时间等对等离子体引发接枝反应的影响,并利用红外光谱、扫描电镜对接枝单体后薄膜表面的化学组成及表面结构进行了表征分析。 相似文献
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利用等离子体引发接枝技术对低密度聚乙烯(LDPE)薄膜进行表面改性处理,通过对接枝单体后LDPE薄膜表面单体接枝率的计算和表面接触角以及表面自由能的测量,系统地研究了反应气体、放电功率、处理时间、处理压力对等离子体引发接枝反应的影响,并利用红外光谱、扫描电镜对接枝单体后薄膜的表面化学组成及表面结构进行了表征分析。 相似文献
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To improve the interfacial adhesion between evaporated copper film and low‐density polyethylene (LDPE) film, the surface of LDPE films was modified by treating with chromic acid [K2Cr2O7/H2O/H2SO4 (4.4/7.1/88.5)]/oxygen plasma. Chromic‐acid‐etched LDPE was exposed to oxygen plasma to achieve a higher content of polar groups on the LDPE surface. We investigated the effect of the treatment time of chromic acid in the range of 1–60 min at 70°C and oxygen plasma in the range of 30–90 sec on the extent of polar groups created on the LDPE. We also investigated the surface topography of and water contact angle on the LDPE film surface, mechanical properties of the LDPE film, and adhesion strength of the evaporated copper metal film to the LDPE film surface. IR and electron spectroscopy for chemical analysis revealed the introduction of polar groups on the modified LDPE film surface, which exhibited an improved contact angle and copper/LDPE adhesion. The number of polar groups and the surface roughness increased with increasing treatment time of chromic acid/plasma. Water contact angle significantly decreased with increasing treatment time of chromic acid/plasma. Combination treatment of oxygen plasma with chromic acid drastically decreased the contact angle. When the treatment times of chromic acid and oxygen plasma were greater than 10 min and 30 sec, respectively, the contact angle was below 20°. With an increasing treatment time of chromic acid, the tensile strength of the LDPE film decreased, and the film color changed after about 10 min and then became blackened after 30 min. With the scratch test, the adhesion between copper and LDPE was found to increase with an increasing treatment time of chromic acid/oxygen plasma. From these results, we found that the optimum treatment times with chromic acid and oxygen plasma were near 30 min and 30 sec, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1677–1690, 2001 相似文献
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Low-density polyethylene (LDPE) films were treated with fuming nitric acid (FNA). The surface characteristics and also the insertion of polar groups like on the etched LDPE film surface were measured by SEM, IR and XPS analyses, respectively. The mechanical performance of a laminate of the etched film with epoxy resin and also the printability of the etched film surface were tested and compared with the unetched sample. The surface roughening and the presence of polar groups enhance the mechanical strength of the laminate of FNA-treated film due to mechanical interlocking and chemical interaction. The printability of the treated film surface is also superior to that of the untreated LDPE film surface. 相似文献
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合成了N,N-二正丁基二硫代氨基甲酸铁(FeDBC)光敏剂,通过元素分析、热谱分析、红外(IR)光谱和紫外(UV)光谱表征了它的组成和性质。进而研究了FeDBC对UV光氧化低密度聚乙烯(LDPE)膜的物理性能、羰基指数和粘均分子量的影响,并探讨了FeDBC在敏化LDPE膜光氧降解方面的作用机理。结果表明,在LDPE膜中加入0.1%~0.3%FeDBC,即成可控寿命的LDPE农膜。 相似文献
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Low‐density polyethylene (LDPE) film was chemically modified by chromic acid treatment to generate polar groups on the surface. The film samples were etched by chromic acid with variation of temperature at a constant time (30 min) and variation of time at a constant temperature (room temperature = 26°C). The variation of weight and thickness of the film samples before and after etching was measured. The surface morphology of the etched films was studied by Scanning Electron Microscopy (SEM). IR and XPS analysis revealed the introduction of polar groups like COOH, 〉CO, SO3H on the etched LDPE film surface, which exhibited improved printability. Etching also enhanced adhesion with epoxy resin. The mechanical properties of the laminates of the two specimens of the same film sample with epoxy resin were also measured. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1041–1048, 1999 相似文献
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This paper deals with photostabilization of low density polyethylene films (LDPE) grafted with the UV-stabilizer 2-hydroxy-4-(3-methacryloxy-2-hydroxy-propoxy) benzophenone (HMB). The influence of grafting yield and the other grafting conditions upon photostabilization efficiency of LDPE films were then studied. The chemically bound monomer (HMB) was localized mainly near the surface of an LDPE film. The grafted LDPE film was exposed to an ultraviolet radiation source, and the degree of oxidation and other photooxidative changes were determined by transmission IR and ATR IR spectroscopy. Experimental results show that radiation grafting of a UV-stabilizer upon LDPE films is an efficient photostabilization method. 相似文献
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Characterization and properties of LDPE film with gallic‐acid‐based oxygen scavenging system useful as a functional packaging material
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We prepared and characterized active, oxygen‐scavenging, low density polyethylene (LDPE) films from a non‐metallic‐based oxygen scavenging system (OSS) containing 1, 3, 5, 10, and 20% of gallic acid (GA) and potassium chloride (PC). We compared the surface morphology and mechanical, permeability, and optical properties of the oxygen‐scavenging LDPE film with those of pure LDPE film. The surface morphology, gas barrier, and thermal properties indicate that the OSS was well incorporated into the LDPE film structure. The surface roughness of the film increased with the amount of oxygen scavenging material. The oxygen and water vapor permeability of the developed film also increased with the amount of oxygen scavenging material, though its elongation decreased. The oxygen scavenging capability of the prepared film was analyzed at different temperatures. The initial oxygen content (%) in the vial headspace, 20.90%, decreased to 16.6% at 4 °C, 14.6% at 23 °C, and 12.7% at 50 °C after 7 days of storage with the film containing 20% OSS. The film impregnated with 20% organic oxygen scavenging material showed an effective oxygen scavenging capacity of 0.709 mL/cm2 at 23 °C. Relative humidity triggered the oxygen scavenging reaction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44138. 相似文献
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Maryam Ataeefard Siamak Moradian Mojtaba Mirabedini Morteza Ebrahimi Said Asiaban 《Progress in Organic Coatings》2009,64(4):482-488
Low-pressure glow discharges of Ar or O2 gas plasmas were used to increase the wettability of low-density polyethylene (LDPE) films in order to improve their adhesion properties hence making them useful in technical applications. Surface free energies of such films were estimated by the aid of contact angle measurements at different exposure power/time combinations for a series of test liquids. Additionally, plasma-treated samples were subjected to several aging processes to determine the durability of different plasma treatments. Characterization of the surface changes due to plasma treatments were carried out by means of attenuated total reflectance, Fourier transform infrared spectroscopy (FTIR-ATR) to determine the presence of polar species such as hydroxyl, carbonyl, carboxyl, etc. groups. Furthermore, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to evaluate changes in surface morphology and roughness. Considering the semi-crystalline nature of the LDPE film, XRD studies were also carried out to determine changes in the percentage of crystalinity. The results showed that all low-pressure Ar or O2 gas plasmas improve the wettability properties of LDPE films. Contact angles decreased significantly depending on the discharge powers and exposure times. Surface morphology was also found to vary with plasma discharge powers, exposure times, and the type of gas being used. Ar gas plasmas comparatively produced superior results. 相似文献
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Grafting of itaconic acid (IA) onto low‐density polyethylene (LDPE) was performed by reactive extrusion where the initiator was dicumyl peroxide, and the neutralizing agents (NAs) were zinc oxides and hydroxides as well as magnesium oxides and hydroxides. The carboxyl groups were neutralized in molten LDPE directly in the course of acid grafting, and in prefabricated functionalized polyethylene (LDPE‐g‐IA). It was found that neutralizing agents introduced into the initial reaction mixture increase the yield of LDPE‐g‐IA while the carboxyl groups were neutralized partially or totally through chemical reactions. The physical structure of LDPE‐g‐IA did not in fact suffer any substantial changes. From the standpoint of neutralization activity, the NAs studied could be arranged as follows: Zn(OH)2 > ZnO > Mg(OH)2 > MgO. NA, added into the initial reaction mixture improved the grafting efficiency of IA onto LDPE. In case of the one‐step process (neutralization simultaneously with grafting), the neutralizing effect appears stronger than that in the two‐step process (neutralization of prepared LDPE‐g‐IA). This means that neutralization of carboxyl groups in IA was less effective when NA was introduced into LDPE‐g‐IA than for the case of the initial reactive mixture. Chemical neutralization of grafted IA results in products of improved resistance to thermal oxidation and thermal stability of melt. This result is of practical importance to the opportunities for widening the application range for PE modified by grafting IA, while preparing polymer blends to be compounded, processed, and used at elevated temperatures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 828–836, 2003 相似文献