Morphology degradation mechanism

A variety of test methods are used to characterise drug-releasing textiles however, the main characteristics that are commonly determined are mechanical properties, morphology, degradation, chemical functionality, and of course drug-loading capacity and release kinetics. 

Lu and Macosko (2004) and Lu et al. (2003) have prepared compatibilized blends of polyurethane with functionalized PP characterizing the blends by rheology, DMA, tensile properties, and morphology. Primary and secondary amine-functionalized PP were more efficient compatibilizers than was PP-g-MA. A degradative mechanism for copolymer formation involving polyurethane chain cleavage was postulated. See also Kobayashi et al. (2011) for related PE/TPU blends. 

The hydrolytic degradation mechanism of P(TMC-co-GA) copolymers can be described by the preferential hydrolysis of GA component in the case of random or segmented copolymers. Morphological and compositional changes are observed. The copolymers can also be degraded by certain enzymes, in particular, lipases which are able to degrade PTMC. 

The hydrolytic degradation mechanism, rate, and behavior are affected by the parameters of materials and media, as summarized in Table 21.2. The material parameters include molecular and highly ordered structures, additives including other polymers and fibers, and the material morphology. The medium parameters include the type and concentrations of catalytic species and other solutes, pH, temperature, and the type and density of microbes. 

The classification scheme illustrated in Figure 13.1 contains many possible connections, not shown. For example, the latex core/shell materials and the latex IPNs differ principally by the presence of cross-links in the latter, but significant morphological and mechanical differences may also occur. The mechanochemical blends are synthesized when a polymer 1/monomer 2 mix is masticated with sufficient shear to degrade polymer 1 to a certain extent. The various free radicals, anions and cations formed then initiate the... 

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