Morphological Test

Classification to genus is often achieved by morphological tests supplemented with a few physiological tests, whereas classification to species level relies heavily on the latter. As an example of the use of physiological criteria... 

Various morphological tests and research results concerning wall failure, as a function of the medium, allow one to identify the mechanism by which oxidative degradation occurs. 

Although visual and microscopical examination, together with simple manual tests, are stiU the primary methods of identification, there are many new sophisticated instmmental methods available based on chemical and physical properties. These methods are able to distinguish between closely related fibers which differ only in chemical composition or morphology. 

There are tests for physical properties such as deasity and hardness (qv) of plastics. Microscopy (qv) is important ia fracture analysis as well as ia analysis of the morphology of polymer systems for an understanding of polymer blend performance. 

Four modes of characterization are of interest chemical analyses, ie, quaUtative and quantitative analyses of all components mechanical characterization, ie, tensile and impact testing morphology of the mbber phase and rheology at a range of shear rates. Other properties measured are stress crack resistance, heat distortion temperatures, flammabiUty, creep, etc, depending on the particular appHcation (239). 

Subscripts denote reinforcement morphology p = particulate, 1 = platelet, w = whisker, f = fiber, i = interlayer between reinforcement and matrix. Strength as measured in a four-point flexure test (modulus of mpture) to convert MPa to psi, multiply by 145. 

Amongst the factors that will influence service performance are the effect of additives and impurities, temperature, detailed geometric size and shape, orientation and morphology, surface condition, energy and speed of any impacting blow, the shape of the impacting instrument, the environment, and strains in the article due to external loads. For this reason it is desirable, but not always feasible, to test prototype articles under conditions as close to service conditions as possible. 

In a mechanical test, interfacial strength may be quantified in terms of either the minimum load required for interface disruption or the total integral energy or work expended. In many situations, due to non-uniformity of chemical or morphological conditions over the area of the interface or to non-uniformity of the applied stress in a given test [7], the two criteria are different. The investigator must thus strive to minimize or deal with both of the above complications, i.e. the interfaces studied should be chemically and morphologically uniform, and the stresses applied in the test should be uniform or distributed in way which is quantitatively describable. 

Fig. 3. Wedge test crack length as a function of maximum Cu buildup at the oxide-metal interface. The adhesive was Cytec FM-123. The surfaces were prepared with the Forest Products Laboratory etch. The oxide morphology was kept constant. Data are from Ref. 115].

A more recent process, the P2 etch [60], which uses ferric sulfate as an oxidizer in place of sodium dichromate avoids the use of toxic chromates, but still provides a similar oxide surface morphology (Fig. 15) allowing a mechanically interlocked interface and strong bonding [9]. The P2 treatment has wide process parameter windows over a broad range of time-temperature-solution concentration conditions and mechanical testing confirms that P2-prepared surfaces are, at a minimum, equivalent to FPL-prepared specimens and only slightly inferior to PAA-prepared surfaces [61]. 

A series of polyester-based TPU (566TPU series) were synthesized in our lab and used to blend with PVC to manufacture a modified PVC material for medical uses [14]. Morphological studies showed that 566TPU has very good compatibility with PVC. Detailed mechanical and electronic property tests were also conducted. Some of the data are provided in Tables 3 and 4. 

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