大分子键合处理氢氧化铝的表面性质及其与常用聚合物的界面特性

本文研究了经大分子以键合方式包覆处理的氢氧化铝粉末的表面性质以及其与常用聚合物的界面特性。结果表明：（１）与未处理过的氢氧化铝相比，非极性液体与处理过的氢氧化铝压片的接触角变化较小，而极性液体与它的接触角一般明显增大。（２）改性后的氢氧化铝的表面张力均明显下降，其中表面张力的极性分量大幅度下降而色散分量稍有提高。与常见聚合物的界面张力以及它的极性分量和色散分量均下降。（３）用弹性体处理的氢氧化铝的     

大分子键合处理氢氧化铝的制备及其与LDPE的性能研究

本文研究了以大分子键合方式包覆处理的氢氧化铝粉末的制备及其与LDPE的界面性质和性能,结果表明：（1）与未处理过的氢氧化铝相比,改性后的氢氧化铝的表面张力均明显下降,其中表面张力的极性分量大幅度下降而色散分量稍有提高。与LDPE的界面张力以及它的极性分量和色散分量均下降。（2）当氢氧化铝的加入量大于1／3以上时,体系的力学性能随着氢氧化铝加入量的增大而逐渐下降。（3）用弹性体处理的氢氧化铝填充聚乙烯的效果优于铝酸酯偶联剂,显示可能有良好的应用前景。     

大分子键合处理碳酸钙的表面性质及其与PVC的界面特性

本文研究了以大分子键合方式包覆处理碳酸钙粉末的表面性质及其填充PVC的界面性质和机械性能，结果表明：（1）与未处理过的纳米轻质碳酸钙相比，所有改性碳酸钙的表面张力均明显下降，其中表面张力的极性分量大幅度下降而色散分量稍有提高。与PVC的界面张力及其极性分量和色散分量均下降。（2）用大分子弹性体键合方式处理的碳酸钙对PVC填充材料具有明显的增韧效果，其效果优于铝酸酯偶联剂，显示可能有良好的应用前景。     

大分子键合处理CaCO3的表面性质及其与PVC的界面特性

研究了以大分子键合方式包覆处理CaCO3粉末的表面性质及其填充PVC的界面性质和力学性能,结果表明:①与未处理的CaCO3相比,所有改性CaCO3的表面张力均明显下降,其中表面张力的极性分量大幅度下降,但色散分量略有提高,与PVC的界面张力及其极性分量和色散分量均下降;②用大分子弹性体键合方式处理的CaCO3对PVC填充材料具有明显的增韧效果,其效果优于铝酸酯偶联剂,显示出良好的应用前景。     

丙烯酸多脂环(烯)酯与其均聚物的表面张力研究

采用滴体积法及Wilhelmy动态接触角测定法测定了丙烯酸双环戌烯基酯 (DCPA)、丙烯酸三环戌烯基酯 (TCPA)、丙烯酸异冰片酯 (IBA)、甲基丙烯酸正丁酯 (BMA)与其均聚物 ,以及氯化聚丙烯 (C1PP)与聚苯乙烯 (PSt)的表面张力及其色散分量与极性分量 ;分别测定了水与CH2 I2 对聚合物PDCPA、PTCPA、PIBA、PBMA、C1PP与PSt表面的动态接触角。以及DCPA、IBA与BMA分别对PSt表面的动态接触角。水、CH2 I2 与PSt为参比物 ,它们的表面张力及其色散分量与极性分量为已知的。从这些数据中得到一些规律性现象 ,并进行了解释。     

丙烯酸多脂环（烯）酯与其均聚物的表面张力研究

本文采用滴体积法及Ｗｉｌｈｅｌｍｙ动态接触角测定法测定了丙烯酸双环戊烯基酯（ＤＣＰＡ）、丙烯酸三环戊烯基酯（ＴＣＰＡ）、丙烯酸异冰片酯（ＩＢＡ）、甲基丙烯酸正丁酯（ＢＭＡ）与其均聚物,以及氯化聚丙烯（ＣＩＰＰ）与聚苯乙烯（ＰＳｔ）的表面张力及其色散分量与极性分量;分别测定了水与ＣＨ２Ｉ２对聚合物ＰＤＣＰＡ、ＰＴＣＰＡ、ＰＩＢＡ、ＰＢＭＡ、ＣＩＰＰ与ＰＳｔ表面的动态接触角。以及ＤＣＰＡ、ＩＢＡ与ＢＭ     

RDX表面能及其分量的测定

采用Washburn薄层毛细渗透技术测定了RDX粉体的接触角和表面能及其色散、极化、电子受供体分量.选用非极性的二碘甲烷和1-溴萘作为测定RDX表面能色散分量的探针液体,极性的乙二醇和甲酰胺作为测定RDX表面能极性分量和酸、碱分量的探针液体.通过测定不同探针液体的渗透曲线,发现基于不同探针液体分子的接触角获得的RDX粉体的表面能成分彼此一致,RDX的总表面能(40.20 mJ · m-2)与理论计算结果(40.60 mJ · m-2)基本一致.测得的色散分量为23.71 mJ · m-2,极性分量为16.49 mJ · m-2,电子受体分量为1.149 mJ · m-2,电子供体分量为51.87 mJ · m-2.结果表明,在RDX的表面能中,色散分量占主要部分,而且在极性分量中电子供体碱性分量明显大于电子受体酸性分量.     

线性低密度聚乙烯接枝丙烯酸的临界表面张力研究

测定了极性液体在不同接枝率的线性低密度聚乙烯接枝丙烯酸（ＬＬＤＰＥ－ｇ－ＡＡ）膜表面的接触角。发现随着接枝率的增加，接触角下降，采用Ｚｉｓｍａｎ作图法和接触角与表面张力的相关关系式得到了不同接枝率ＬＬ－ＤＰＥ－ｇ－ＡＡ的临界表面张力。     

表面能、润湿和粘附

固体的表面能可以用已知表面张力的液体的接触角和它对极性或者酸—碱的敏感性进行估算。界面张力和粘附则可以用估算的表面能来进行计算。性能和粘接强度与表面能有关,有三种情况:界面分离;界面不完全润湿;界面处有第三相存在。     

^60Co辐照对PTFE表面结构和表面能的影响

为了改善氟聚合物加工性和二次加工性,研究了PTFE聚合物的加工技术。以不同剂量辐照PTFE,PTFE粉末辐照后表面晶相没有发生变化。模压辐照的PTFE,其密实性较好,表面光滑。同时,辐照PTFE后表面有大量的极性亲水基团出现,使表面极性分量增加;而色散分量变化较小。辐照产生的表面极性基团减小了由于不同模压产生的表面所引起的接触角变化。     

Contact angle measurements and interpretation: wetting behavior and solid surface tensions for poly(alkyl methacrylate) polymers

Low-rate dynamic contact angles of a large number of liquids were measured on a poly(ethyl methacrylate) (PEMA) polymer using an automated axisymmetric drop shape analysis profile (ADSA-P). The results suggested that not all experimental contact angles can be used for the interpretation in terms of solid surface tensions: eight liquids yielded non-constant contact angles and/or dissolved the polymer on contact. From the experimental contact angles of the remaining four liquids, we found that the liquid-vapor surface tension times the cosine of the contact angle changes smoothly with the liquid-vapor surface tension, i.e. γlv cos ζ depends only on γlv for a given solid surface (or solid surface tension). This contact angle pattern is again in harmony with those from other methacrylate polymer surfaces of different compositions and side-chains. The solid-vapor surface tension of PEMA calculated from the equation-of-state approach for solid-liquid interfacial tensions was found to be 33.6 ± 0.5 mJ/m2 from the experimental contact angles of the four liquids. The experimental results also suggested that surface tension component approaches do not reflect physical reality. In particular, experimental contact angles of polar and nonpolar liquids on polar methacrylate polymers were employed to determine solid surface tension and solid surface tension components. Contrary to the results obtained from the equation-of-state approach, we obtained inconsistent values from the Lifshitz-van der Waals/acid-base (van Oss and Good) approach using the same sets of experimental contact angles.     

Low-rate Dynamic Contact Angles on Poly(methyl methacrylate/n-butyl methacrylate) and the Determination of Solid Surface Tensions

Low-rate dynamic contact angles of 12 liquids on a poly(methyl methacrylate/n-butyl methacrylate) P(MMA/nBMA) copolymer are measured by an automated axisymmetric drop shape analysis-profile (ADSA-P). It is found that 6 liquids yield non-constant contact angles, and/or dissolve the polymer on contact. From the experimental contact angles of the remaining 6 liquids, it is found that the liquid- vapour surface tension times the cosine of the contact angle changes smoothly with the liquid-vapour surface tension, i.e., γ_iv cos θ depends only on γ_iv for a given solid surface (or solid surface tension). This contact angle pattern is in harmony with those from other inert and noninert (polar and non-polar) surfaces [34-42, 51 -53]. The solid-vapour surface tension calculated from the equation-of-state approach for solid -liquid interfacial tensions [14] is found to be 34.4 mJ/m², with a 95% confidence limit of \pm 0.8mJ/m², from the experimental contact angles of the 6 liquids.     

Estimation of interfacial tension components for liquid–solid systems from contact angle measurements

A technique has been developed for estimating the hydrogen bonding and London dispersion force components of liquid surface tension and solid surface free energy levels. The technique relies on (a) measuring contact angles generated by sessile drops of liquids on solids and (b) performing calculations based on theories of thermodynamic wetting of solids by liquids. The technique is used to estimate interfacial force components of certain liquids and papers typical of those used in xerographic processing.     

用接触角法测量聚合物共混体系的表面性能

利用接触角的方法研究了聚合物HDPF、PET及其共混物HDPE／PET的表面自由能、极化度以及与不同液体一水和甘油间界面张力的大小。     

花生壳粉表面性能及木塑复合材料界面性能的研究

通过动态法研究了浸润粉层的液体质量的平方随时间的变化规律,测定了不同探测液对花生壳的接触角。采用平衡接触角仪测定了探测液对改性聚乙烯的接触角,进而根据Focks理论推导出花生壳和改性聚乙烯的表面自由能及其极性分量和非极性分量,并计算出花生壳粉/聚乙烯复合材料的界面张力和黏附功。结果表明:相容剂Bondyram 5108的加入,使聚乙烯的极性分量和非极性分量都不同程度地增加,改善了花生壳粉在聚乙烯基体中的分散性,降低了复合材料的界面张力,增大了黏附功。     

Surface modification of HDPE and PP by mechanical polishing and DC glow discharge and their adhesive joining to steel

To improve the strengths of the adhesive joints of high density polyethylene (HDPE) and polypropylene (PP) to steel, the surfaces of HDPE and PP sheets have been treated by DC glow discharge to increase the polar component of surface energy significantly. Present study investigates the effect of mechanical polishing prior to surface modification of substrates of HDPE and PP sheets by exposure to DC glow discharge, on the surface energy and their adhesive joint strength to steel. The mechanical polishing has been carried out by abrading with 120, 220, 400, 600, 800, and 1000 grade emery paper of grit sizes 8.33, 4.54, 2.5, 1.67, 1.2, and 1 micron, respectively. The surface energy of a given surface has been evaluated by measuring contact angles of sessile drops of two test liquids of known surface tension components, such as deionized water and formamide. It is observed that 800‐grade emery paper of grit size 1.2 micron has been found most effective in terms of their reduction in contact angles and enhancement of their surface energies. The change in surface energy due to surface modification has also been evaluated by measuring the surface energies of unpolished sheets exposed to DC glow discharge. The surface modification of the polymers by glow discharge for 120 s at a power level of 13 W decreases the contact angle more on mechanically polished specimens than that observed on unpolished sheets. Due to glow discharge treatment, the polar component of surface energy increases significantly in HDPE and PP, especially when they are mechanically polished (800 grade) prior to glow discharge. However, in case of the HDPE sheets, the effect of glow discharge on the polar component of surface energy is significantly higher compared to that for dispersion component of surface energy, whereas the polar component of surface energy of the PP sheet is lower than the dispersion component of surface energy. But in both the cases, mechanical polishing prior to glow discharge appears to affect the polar component of surface energy. Mechanical polishing of the HDPE and PP sheets by abrading with 800‐grade emery paper prior to glow discharge treatment, increases the adhesive joint strengths over those observed in case of unpolished polymers exposed to glow discharge. However, the use of prior mechanical polishing increases the joint strength only by a little more than 10% compared to a five to seven times increase in strength observed as a consequence of exposure to glow discharge of as received samples. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1140–1149, 2001     

Estimation of the surface free energy of polymers

A method for measuring the surface energy of solids and for resolving the surface energy into contributions from dispersion and dipole-hydrogen bonding forces has been developed. It is based on the measurement of contact angles with water and methylene iodide. Good agreement has been obtained with the more laborious γ_c method. Evidence for a finite value of liquid-solid interfacial tension at zero contact angle is presented. The method is especially applicable to the surface characterization of polymers.     

Low-rate dynamic contact angles on polystyrene and the determination of solid surface tensions

Low-rate dynamic contact angles of 13 liquids on a polystyrene polymer are measured by an automated axisymmetric drop shape analysis – profile (ADSA-P). It is found that 7 liquids yielded non-constant contact angles, and/or dissolved the polymer on contact. From the experimental contact angles of the other 6 liquids, it is found that the liquid-vapor surface tension times cosine of the contact angle changes smoothly with the liquid-vapor surface tension, i.e. γ_lvcosθ depends only on γ_lv for a given solid surface (or solid surface tension). This contact angle pattern is in harmony with those from other inert and non-inert (polar and non-polar) surfaces (7–13, 24–26). The solid-vapor surface tension calculated from the equation-of-state approach for solid-liquid interfacial tensions (33) is found to be 29.8 mJ/m², with a 95% confidence limit of ±0.5 mJ/m² from the experimental contact angles of 6 liquids.