Adhesive bond strength tests

Deflection temperature under load (DTUL) measures the temperature at which a specimen of a certain geometry deflects a fixed amount under a very specific set of conditions. However, it is often used in material selection as a measure of the maximum continuous use temperature for that material. The development of dynamic mechanical analysis (DMA) has shown that traditional DTUL test results often give a false measure of the thermal performance of polymeric materials. By measuring the elastic modulus versus temperature by DMA the thermal profile of any polymer can be obtained and a more realistic assessment of the elevated temperature performance can be obtained. New techniques were also presented for testing adhesive bond strength tests for piping systems. The technique developed utilized lap-shear plaques to predia performance in the pipe joint systems. Results indicate extreme sensitivity to minor variations in preparation. 

Each of the multilayered materials of Table II, in pouch form, met the retortability requirements. Examination of the pouches after this test showed that no delamination occurred among the layers. However, microscopic examination of specimens used for bond strength tests showed that adhesive failure rather than cohesive failure occurred be-... 

Based on its apparent simplicity, scratch testing is frequently applied to estimate the cohesive and adhesion bond strengths of hydroxyapatite coatings (for example Arias et al., 2003 Zhang et al., 2006 Dudek and Adamczyk, 2013). However, the interpretation of the recorded traces is difficult as the test results are affected by scores of intrinsic and extrinsic parameters that tend to falsify the conclusion drawn. 

The adhesive bond strength of PU varies with the degree of acid-base interaction with the substrate and with the conformational state of the adhesive molecule at the time of testing. Being basic, PU develops stronger bonds with acidic substrates (PVC in this case) than with basic ones, this is exemplified by ABS. 

Sulfuric acid-dichromate is the most commonly applied chemical etching treatment for many plastics. There are few hard rules to determine the composition of this treatment media, although ranges can be found (Table 3.3). The exact formulation should be determined by testing the adhesive bond strength for any given plastic. Combinations of chromic acid, sulfuric acid, and phosphoric acid have been successfully used. "... 

Thompson R.B. and D.O. Thompson, Past experiences in the development of tests for adhesive bond strength. J. Adhesion Sci. Technol, 5(8) 583-599, 1991. 

With adhesives, therefore, the same test method may be quoted for widely differing materials and the standards are written in such a way as to take account of this. For instance, BS 5350 Part C5, the lap shear bond strength test (see Shear tests), may be nsed to determine the bond strength of adhesives of widely different cohesive strengths on substrates of widely differing nature. 

Working Life of Liquid or Paste Adhesive by Consistency and Bond Strength. Test for (D 1338) ... 

Shear bond or tensile tests determine the dental adhesive bond strength, with thermocycling in water effectively evaluating the bond durability. The monomer VBATDT is effective for bonding Ag-Pd alloy, while 4-META is suitable for Ni-Cr alloy and titanium. For Ni-Cr alloys, the chromium content influences bond durability. Ferric chloride combined with a silane coupler significantly improves the bond strength of 4-META/MMA-TBB-O resin joined to dental porcelain. 

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