多波段激光防护PMMA材料的制备

以聚甲基丙烯酸甲酯(PMMA)为基材．在基材中加入防激光吸收剂IR530、IR1065,制备了能有效吸收488nm、514nm、530nm、1060nm等多个波长激光的PMMA材料。通过实验研究确定了防激光吸收剂IR530、IR1065的加入量和激光防护PMMA材料的制备工艺参数。结果表明,多波段激光防护PMMA材料在488nm、514nm、530nm处的透过率为0．01％,在1060nm处的透过率为0．02％,具有良好的激光防护性能。同时防激光吸收剂的加入对材料的冲击强度影响很小。     

防眩光及紫外/蓝光防护功能涂层的制备及性能研究

以气相二氧化硅粒子及紫外吸收剂为功能助剂,氟碳改性高反应丙烯酸树脂为主体树脂,聚对苯二甲酸乙二醇酯(PET)聚酯膜为基材,采用湿法涂布工艺制备了具有防眩光和紫外/蓝光防护特性的功能涂层。研究了二氧化硅粒子含量、紫外吸收剂类型、所占比例以及涂层厚度对功能涂层性能的影响。结果表明,制备的UV固化吸光防眩光涂层兼具优异的防眩光和紫外/蓝光吸收性能,能有效改善显示屏幕表面发白和晃眼的问题。随着二氧化硅粒子含量的增加,涂层的雾度升高,同时光透过率和镜面光泽减小。紫外吸收剂HY-UV5具有最优的紫外/蓝光吸收性能。紫外吸收剂含量以及涂层厚度的增加,都能有效提高涂层的紫外/蓝光防护性能。此外,该涂层还具有优异的耐污和耐划伤性能。     

双透明PMMA塑料激光表面预处理及焊接工艺

无需添加吸收剂对透明聚甲基丙烯酸甲酯(PMMA)塑料直接进行激光焊接,减少吸收剂的残留,同时通过优化工艺提高焊缝强度。采用CO₂激光对塑料表面进行预处理,增加材料表面对激光能量的吸收率,然后采用半导体激光器进行透射焊接实验,采用原子力显微镜(AFM)测试焊缝表面状态,采用X射线光电子能谱技术(XPS)测试焊缝表面材料的自由能。经过CO₂激光预处理后,对激光的吸收率进一步增强,焊缝拉伸强度测试结果表明,经过CO₂激光表面预处理后的焊缝拉伸强度为57 MPa,比未预处理的焊缝提高了2倍。CO₂激光表面预处理提高了材料表面的粗糙度,促进了分子链的扩散和纠缠,将有利于提高焊缝拉伸强度。     

光纤激光打标工艺对黑色PMMA材料打标效果的影响

采用峰值功率为30 W的光纤激光打标设备,在不同线间距、激光功率、打标速度和激光频率等打标工艺参数下对黑色聚甲基丙烯酸甲酯(PMMA)材料进行光纤激光打标,研究了这些打标工艺参数对黑色PMMA材料打标效果的影响规律,并筛选出了黑色PMMA材料的最佳打标工艺参数。结果表明,随着线间距和打标速度的增大,黑色PMMA材料的打标图案均呈现出了从烧焦发黑到清晰明亮再到昏暗模糊的变化趋势;而随着激光功率的变大,打标图案却由清晰变模糊再变烧焦。当激光频率变大时,打标图案有从明亮逐渐变暗的趋势,但是变动幅度很小。获得的黑色PMMA材料的理想打标工艺参数区间为线间距0.17～0.21 mm,激光功率为峰值功率的10%～25%,打标速度300～500 mm/s,激光频率20～40 kHz。特别地,当线间距为0.2 mm、激光功率为峰值功率的10%、打标速度为300 mm/s、激光频率为20 kHz时,打标时间、打标宽度和打标深度分别为1.86 s,130 μm和30.38 μm,此时黑色PMMA材料的打标效果最佳。     

PMMA/纳米ZnO薄膜的紫外屏蔽性能研究

采用硅烷偶联剂对纳米ZnO进行了表面改性,并采用旋转涂膜法制备了聚甲基丙烯酸甲酯(PMMA)/纳米ZnO薄膜,研究了薄膜的紫外屏蔽性能。结果表明,表面改性的纳米ZnO在水和甲苯中均无明显沉淀现象,其溶解性得到改善;改性纳米ZnO红外图谱中877cm-1处出现的新吸收峰,可证实偶联剂已成功修饰于粒子表面;光学显微镜与原子力显微镜测试表明,改性ZnO在PMMA薄膜中的颗粒团聚减少,其分散性得到改善。当PMMA在甲苯中浓度为0.04g/mL、纳米ZnO为PMMA质量的10%时,薄膜的紫外屏蔽性能最好,紫外区透过率为0.66;相同配比的PMMA/改性ZnO薄膜的紫外屏蔽性能明显提高,紫外区透过率为0.53。     

新型核-壳改性剂N-AIM对PMMA性能的影响

通过乳液聚合方法制备了不同橡胶粒径和橡胶相组成比的新型核-壳丙烯酸酯类抗冲改性剂（N-AIM）,将其与聚甲基丙烯酸甲酯（PMMA）进行熔融共混,得到了PMMA/N-AIM共混物。对PMMA/N-AIM共混物的形态结构、冲击性能和光学性能分别进行了考察。通过透射电镜（TEM）分析表明,橡胶粒径为100 nm时改性剂在基体中发生聚集,大于100 nm时均可均匀分散在基体中;冲击测试结果表明,随着N-AIM橡胶粒径的增加,共混物的冲击强度先增大后减小;光学测试表明橡胶组成比影响共混物的光学性能。     

CPVC/PMMA共混体系的性能研究

制备了氯化聚氯乙烯/聚甲基丙烯酸甲酯(CPVC/PMMA)共混材料,研究了PMMA的引入对CPVC/PMMA共混体系的力学性能、耐热性能、表面光泽度、加工流动性和微观结构的影响。结果表明:适量PMMA的引人,使CPVC/PMMA共混体系的缺口冲击强度和光泽度较纯CPVC显著提高,耐热性能亦有所改善,而拉伸强度下降不明显;塑炼过程中,CPVC/PMMA共混体系熔体的平衡扭矩降低,凝胶化时间减少。当PMMA含量为15 phr时,CPVC/PMMA共混体系具有最佳综合性能,此时该共混体系的缺口冲击强度为5.4 kJ/m2,拉伸强度为53.5 MPa,表面光泽度为82.3%,热变形温度为102.4℃,平衡扭矩为20.1 N·m。     

发光材料在防眩光交通监控补光照明中的应用

交通监控补光源在工作时产生的强烈眩光会干扰驾驶员视线,从而给道路安全带来了隐患。考虑到人眼对于不同色光的敏感程度,通过改进补光源的光谱分布,提高人眼较不敏感的红光部分,能够有效地减轻眩光。这需要改变发光器件中的荧光粉组成。本文通过高温固相反应法制备了铈掺杂的钇铝镓石榴石基黄绿色荧光粉以及铕掺杂的钙锶铝硅氮化物红色荧光粉。所合成样品均为纯相,粉末颗粒分布均匀。光谱测试表明,样品能够被可见蓝光有效激发,发射光分别位于黄绿光区和红光区。将上述荧光粉与蓝光芯片复合封装得到发光器件。测试表明,红色荧光粉能够显著改善发光器件的色温、显色指数等照明品质,在保持白光的同时能够减少光谱中的黄绿光部分,从而缓解眩光效应。     

PMMA在空腔铜靶制备中的应用

针对整体式空腔铜靶体积很小而不能采用机械加工制造的状况,选用聚甲基丙烯酸甲酯(PMMA)作为芯轴,在其表面化学镀铜,制备出空腔铜靶;将PMMA溶解于有机溶剂中制成涂料,用于铜靶的防氧化保护;然后使用有机溶剂将PMMA芯轴及PMMA保护膜溶蚀后可制得空腔铜靶成品。     

PMMA注射成型工艺及优化

在分析聚甲基丙烯酸甲酯（PMMA）的注射成型工艺特性的基础上,讨论了影响PMMA制品质量的工艺因素,包括模具及其浇口设计、烘干处理、注射温度、注射速率、注塑压力、停机处理等。并针对PMMA注塑制品常见缺陷提出了工艺优化措施。     

Physical ageing of polycarbonate and PMMA by dynamic mechanical measurements

The physical ageing properties of polycarbonate and poly(methyl methacrylate) have been measured by dynamic mechanical experiments at different temperatures. It appears that the horizontal shift proposed by Struik to superpose the experimental curves for different ageing times is only a first approximation. The McCrum analysis has been used in the α region but cannot be applied between the α and β relaxations.     

Synthesis and properties of poly(methyl methacrylate)/montmorillonite (PMMA/MMT) nanocomposites

PMMA/MMT nanocomposites were successfully synthesized via in situ intercalative polymerization, and characterized by means of wide‐angle X‐ray diffractometry, transmission electron microscopy, thermal gravimetric analysis, dynamic mechanical analysis and Fourier‐transform infrared analysis. The nanocomposites possess partially exfoliated and partially intercalated structure, in which the silicate layers are exfoliated into nanometre secondary particles with thickness of less than 20 nm and uniformly dispersed in the polymer matrix. In comparison with pure PMMA, the thermal stability, glass transition temperature, and mechanical properties of the polymer are notably improved by the presence of the nanometric silicate layers. It was found that part of the PMMA chains in the nanocomposites are well immobilized inside and/or onto the layered silicates and, therefore, the unique properties of the nanocomposites result from the strong interactions between the nanometric silicate layers and the polymer chains. Copyright © 2003 Society of Chemical Industry     

不同组成ABS对ABS／PMMA合金性能的影响

选用两种不同牌号的ABS树脂与PMMA共混，对其组成与性能的关系进行了详细的研究。试验结果表明，不同组成的ABS对ABS/PMMA混合物的光学性能、力学性能以及流变行为的影响都有显著的不同．     

OH基对磷酸盐激光玻璃激光性能和物理性质的影响

研究了ＯＨ基对ＨＬＣ＿５型（Ｒ２Ｏ－ＢａＯ－Ａｌ２Ｏ３－Ｐ２Ｏ５）和Ｎ２１型（ＢａＯ－Ａｌ２Ｏ３－Ｐ２Ｏ５）磷酸盐激光玻璃激光性能和物理性质的影响．结果表明：随着ＯＨ基含量的降低,玻璃的荧光寿命延长,量子效率增大,转变温度、软化温度、抗折强度和折射率升高,而热膨胀系数和平均色散下降,密度略有下降．用ＯＨ基与激活离子的相互作用和ＯＨ基对玻璃结构的影响的有关理论对上述结果进行了解释．     

A LASER INTERFEROMETER FOR MONITORING THIN FILM PROCESSES: APPLICATION TO POLYMER DISSOLUTION

An instrument has been assembled which is well suited for monitoring changes in transparent films and coatings where the thickness ranges from several μm down to fractions of a μm. The operation is based on thin film optical interferometry. Applications include measurement of the dissolution rate in selected organic solvents of a 2-μm thick film of poly(methyl methacrylate) (PMMA) which has been coated on a silicon-oxide-surfaced silicon wafer. Such measurements are often required in developing images from electron-beam or X-ray exposure in microlithography and microelectronics. An unpolarized light beam from a 2 mW He-Ne laser is directed obliquely onto the surface of the film. From the time dependence of the intensity of reflected light, both the rate of dissolution and the refractive index of the film can be ascertained. A review of the optical theory upon which such measurements are based is included. The scope of additional information obtainable through application of this technique, including assessment of the optical integrity of polymer/liquid boundaries during dissolution, is also discussed.     

PMMA/MC复合胶粒的制备及在尼龙中的应用

采用原位乳液聚合法制备了聚甲基丙烯酸甲酯(PMMA)／三聚氰胺氰尿酸盐(MC)复合胶粒,对其进行X光电子能谱及热重分析结果显示,在MC阻燃剂颗粒表面覆盖了一层PMMA胶膜,形成了具有核-壳结构的PMMA／MC复合胶粒;MC能影响PMMA的热降解过程并促进其成炭;在尼龙6(PA6)中的应用结果表明,PMMA／MC复合胶粒能改善PA6的力学性能和阻燃性能。     

Material Formulations for AR/PMMA and AR-TiO2/PMMA Blends and Effects of UV Radiation and Tio2 Loading on Mechanical and Antibacterial Performances

Polymer blends of poly(methyl methacrylate)(PMMA) and acrylic rubber(AR) were manufactured with the addition of titanium dioxide (TiO₂). TiO₂ was initially added to the AR phase in AR/PMMA blends. The impact strength of PMMA improved with AR loading. The addition of TiO₂ appeared to decrease the tensile properties of the blends with AR of 10-30?wt% of AR, but increased with AR of 40-50?wt%, this being related to distribution level of TiO₂. UV radiation deteriorated the overall mechanical properties, where TiO₂ could retain the properties. To achieve acceptable antibacterial performance, AR loadings of 40 and 50?wt% in AR-TiO₂/PMMA blends are recommended, together with TiO₂ loadings of 1.5?pph and 0.5?pph, respectively.     

悬浮聚合聚甲基丙烯酸甲酯／蒙脱土纳米复合材料的制备及表征

采用悬浮聚合法制备了聚甲基丙烯酸甲酯／蒙脱土（PMMA/MMT）纳米复合材料，利用X射线衍射仪、透射电子显微镜和傅里叶变换红外光谱等手段表征了复合材料的结构，研究了不同改性剂对复合材料结构的影响。通过热重分析考察了复合材料的热性能。结果表明，通过悬浮聚合可以成功制备剥离型纳米复合材料，PMMA基体与MMT可以产生较强的相互作用。MMT的加入可以显著提高复合材料的热稳定性。当MMT含量为10％（质量分数，下同）时，PMMA的最大分解温度提高了15℃。