Transfer efficiency for airless painting systems

Spray transfer efficiency (TE) is defined as the mass fraction of sprayed paint which is deposited on the intended target, the remainder of the sprayed paint becomes undesirable overspray. The relationship between TE and gun supply pressure (or paint mass flow rate), gun-to-target distance, gun traverse speed, the angle of the spray gun relative to the target (gun-to-target angle), plus spray cone angle is reported herein for a typical fan spray system. Experimental results indicate that spray momentum rate (SMR) and droplet size dictate the TE for the various combinations of parameters considered here. The key finding is that TE correlates with SMR and spray mean drop size (Sauter mean diameter, or D₃₂) via an expression of the form TE=a+b SMR − c (SMR)²+d D₃₂, where a, b, c, and d are coefficients, determined by fitting the experimental data, and SMR is estimated via SMR=m²/ρA, where the paint mass flow rate m, the paint density is ρ, and the gun exit orifice effective tip cross sectional area is A. This expression accounts for physical phenomena that govern sprayed droplet deposition characteristics, such as entrainment, bounce-back, and drop size. Experimental results also show that, for the range of parameters studied, gun traverse speed has no effect on TE, but increasing the angle of the spray gun relative to the target (gun-to-target angle), increasing the spray cone angle, or increasing the gun-to-target distance will decrease TE.     

P(SBR/NR/HAF)并用胶的性能

在SBR胶乳／NR胶乳共混的基础上，采用凝聚共沉法制备高耐磨炭黑（HAF）填充型粉末丁苯橡胶／天然橡胶并用胶[P(SBR/NR/HAF)]。研究了SBR／NR并用比、制备工艺等对P（SBR／NR／HAF）并用胶的混沌流变性能和物理机械性能的影响，并与块状SBR／NR／HAF并用胶进行了比较。研究表明，与SBR／NR／HAF相比，P（SBR／NR／HAF）的表观剪切粘度在SBR用量小于50份时对混炼时间的依赖性较低，而在SBR用量大于50份后对混炼时间具有更高的依赖性；P（SBR／NR／HAF)硫化胶 拉伸强度在整个并用范围内对SBR／NR并和比不敏感；采用胶乳预混合的工艺制备的P（SBR／NR／HAF）具有较好的物理机械性能。     

改性沥青用丁苯胶乳粉末化制备及应用

以丁二烯和苯乙烯为原料，采用高低温复合工艺制备了高固含量(60%)丁苯橡胶乳液，后经凝聚法制备出粒径分布均匀(＜1mm)的粉末丁苯橡胶(PSBR)，探讨了凝聚原理，并优化了粉末丁苯橡胶的制备工艺。通过偏光显微镜研究了粉末丁苯橡胶形成阶段的形貌变化。结果表明，凝聚阶段的絮凝剂、凝聚剂和隔离剂对PSBR形貌影响最大。复配隔离剂(硬脂酸钠、油酸钠和硅油)的隔离效果最好，使用氯化钠为絮凝剂〔添加量为1.3%（以胶乳质量为基准，下同）〕，硫酸镁为凝聚剂（添加量为2.5%）时，丁苯胶乳成粉效果最佳，呈均匀粒径的粉末状橡胶。使用PSBR改性70#基质沥青，PSBR添加量为1.0%（以沥青的质量为基准，下同）时，改性沥青的软化点由70#基质沥青的47.6℃提高到51.8℃，5℃延度提高到100cm以上，优于目前丁苯橡胶(SBR)胶粉改性沥青。     

TR-96型地毯粘合剂合成与研究

介绍了自交联丙烯酸聚树脂乳液的合成方法，对该合成反应的投料比例，反应温度，反应时间等基本工艺作了分析和探讨。     

复合型调湿涂料的研制及实验研究

将硅藻土做成乳胶型涂料，并得到了不同湿度下这种涂料的吸放湿性能曲线，但是吸放湿能力不是很理想。为了提高涂料的吸放湿能力，在基料中加入无机成膜物质制成硅藻土复合涂料，结果表明，通过复合，最大吸湿能力从6．5％提高到11％，最大放湿能力从5％提高到10％，并且确定了无机成膜物质的比例。复合涂料符合建筑涂料的常规性能要求，在调节湿度的同时克服了传统空调能耗高的缺点，具有很好的应用前景。     

丁苯橡胶对水泥水化过程及水泥石微观结构的影响

用多种实验手段研究了在普通硅酸盐水泥中掺入丁苯橡胶乳液对水泥水化过程的影响，并用扫描电镜分析了掺入丁苯橡胶后水泥石微观结构形态的改变，从而探讨了丁苯橡胶改善水泥石物理力学性能的机理。     

共挤保护膜研究概况

介绍了共挤保护膜的特点及国外发展现状以及共挤保护膜所用基材种类及特点，压敏胶主要成分及作用。     

变压吸附(PSA)空分制氧技术进展

论述了 PSA法空分制氧分子筛的开发现状和制氧工艺的进展 ,为 PSA法空分制氧今后的发展提出了研究方向     

Morphologies and dynamic mechanical properties of core‐shell emulsifier‐free latexes and their copolymers for P(BA/MMA)/P(MMA/BA) and P(BA/MMA)/PSt systems in the presence of AHPS

Different poly(methyl methacrylate/n‐butyl acrylate)/poly(n‐butyl acrylate/methyl methacrylate) [P(BA/MMA)/P(MMA/BA)] and poly(n‐butyl acrylate/methyl methacrylate)/polystyrene [P(BA/MMA)/PSt] core‐shell structured latexes were prepared by emulsifier‐free emulsion polymerization in the presence of hydrophilic monomer 3‐allyloxy‐2‐hydroxyl‐propanesulfonic salt (AHPS). The particle morphologies of the final latexes and dynamic mechanical properties of the copolymers from final latexes were investigated in detail. With the addition of AHPS, a latex of stable and high‐solid content (60 wt %) was prepared. The diameters of the latex particles are ～0.26 μm for the P(BA/MMA)/P(MMA/BA) system and 0.22–0.24 μm for the P(BA/MMA)/PSt system. All copolymers from the final latexes are two‐phase structure polymers, shown as two glass transition temperatures (T_gs) on dynamic mechanical analysis spectra. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3078–3084, 2002     

两步法合成大粒径丁苯胶乳

研究了聚甲基丙烯酸甲酯（MMA）对丁苯（BS）胶乳的附聚作用以增大丁苯胶乳粒径；探讨了无机盐、体系pH值及体系中MMA胶乳与BS胶乳的固含量比（R值）对附聚后丁苯胶乳的粒径及稳定性的影响。结果表明：适当添加无机盐可以稳定胶乳体系，最佳用量（质量分数）为0．1％～0．2％；适当增大体系pH值，可增大胶乳粒径；在附聚过程中，当R值在两个附聚峰附近时，可增大丁苯胶乳的粒径。