Adhesives characterization

In order to calculate polymer/filler interaction, or more exactly the reversible work of adhesion characterizing it, the surface tension of the polymer must also be known. This quantity is usually determined by contact angle measurements or occasionally the pendant drop method is used. The former method is based on the Young, Dupre and Eowkes equations (Eqs. 21,8, and 10), but the result is influenced by the surface quality of the substrate. Moreover, the surface (structure, orientation, density) of polymers usually differs from the bulk, which might bias the results. Accuracy of the technique maybe increased by using two or more liquids for the measurements. The use of the pendant drop method is limited due to technical problems (long time to reach equilibrium, stability of the polymer, evaluation problems etc.). Occasionally IGC is also used for the characterization of polymers [30]. 

Rasti, N., Namusoke, F., Chene, A., Chen, Q., Staalsoe, T., Klinkert, M. Q., Mirembe, F., Kironde, F., and Wahlgren, M. (2006). Nonimmune immunoglobulin binding and multiple adhesion characterize Plasmodium falciparum-infected erythrocytes of placental origin. Proc. Natl. Acad. Sci. USA 103,13795-13800. 

Newly developed adhesives characterized by strength, heat resistance, and noncombustibility better meet the requirements of the technology. 

PHYSICS OF ADHESION-CHARACTERIZATION OF SURFACE AND BULK OF ADHESIVE SYSTEMS... 

II. Physics of Adhesion - Characterization of Surface and Bulk of Adhesive Systems... 

Data are listed below for the average force of adhesion characterizing the adhesion of particles to a steel surface with a Class 5 finish, for particles with regular and irregular shape ... 

The XPS is used for the determination of elements and their valence states in the surface of the material i.e., surface characterization to provide information about the chemical/oxidation states of various elements present in the surface (at depths <1,000 A) of the material. This aspect is widely used in polymer chemistry, adhesive characterization, corrosion, and metallurgy. 

The application of these principles to an actual adhesively bonded joint is anything but straightforward. One problem is the lack of pertinent information on the performance of adhesive joints. Most test data generated by adhesive producers are only useful for comparison purposes and are of limited use to the design engineer. Also, there is only limited information available on the performance of bonded joints exposed to service environments, while subjected to static or dynamic stresses. Adequate adhesive characterization and prediction of joint durability remain goals for the future. 

Hadin Lin, S.G., 2010. Cow blood adhesive characterization of physicochemical and adhesion properties. Int. J. Adheion Adhesives 30, 139—144. 

Prakash, S. B., Abshire, P., Urdaneta, M. and Smela, E. (2005) A CMOS capacitance sensor for cell adhesion characterization, IEEE International Symposium Circuits and Systems (ISCAS05), 23-26 May 2005, Kobe, Japan, 4, 3495-8. 

The conventional method for characterizing natural rubber, Mooney viscosity, is not sensitive enough to be used to obtain the necessary information for natural rubber-based pressure-sensitive adhesive characterization. The RDS generates better information than the Mooney viscometer. 

ISO 10354 1992 Adhesives - Characterization of durability of structural-adhesive-bonded assemblies - Wedge rupture test... 

EN 1966 2003 Structural adhesives - Characterization of a surface by measuring adhesion by means of the three point bending method... 

Interfacial tension of solid-liquid and solid-solid interfaces Yes (many methods, e.g. Fowkes, Hansen, van Oss-Good) Wetting, adhesion, characterization and modification of surfaces... (paints, glues...)... 

Arcan et aL (1978) proposed a biaxial fixture, commonly known as the Arcan fixture, to produce biaxial states of stress. The compact nature of the Arcan fixture enables obtaining the shear properties in all in-plane directions in a relatively simple manner. The Arcan fixture can be used to apply both shear and axial forces to the test specimen. The adhesive characterization in mixed mode loading allows for the generation of the yield surface of the adhesive in the hydrostatic versus the von Mises plane, which enables one to develop more accurate adhesive models for better simulations. Several modifications to the original test fixture have been proposed to include compression, such as that by El-Hajjar and Haj-Ali (2004). A scheme of the test fixture is shown in O Fig. 19.17. 

There are a lot of specific techniques that provide valuable information related to polymeric adhesives characterization. The more commonly used microscopy techniques are listed in O Table 43.2, including some figures about size ranges and magnifications. Every microstruc-tural characteristic is related to the overall mechanical behavior of the adhesive, and the use of all or some of these techniques can help in the postfracture analysis of the joints. 

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