Polymers elongation

Stage I 0 to 120% strain the structure of the elongated polymer is still very close to that of the original material, and, therefore, no large difference is seen in the photodegradation rate. 

EM). The initiation is a nucleophilic attack of water, which is probably contained in the enzyme, onto the acyl carbon of the intermediate to produce m-hy-droxycarboxylic acid (n= 1), the shortest propagating species. In the propagation stage, the intermediate is nucleophilically attacked by the terminal hydroxyl group of a propagating polymer to produce a one-unit-more elongated polymer chain. 

Addition reactions that are characteristic of head-to-tail addition of subunits to an elongating polymer. Note that the rates of subunit addition to each of the two ends usually differ as a consequence of differences in the geometry of the associated transition states. 

Atactic polymer (Section 30.4) A polymer having the substituents randomly oriented along the carbon backbone of an elongated polymer chain. 

For a non-phase-separated blend of P H B/ P LA, the visual image of the elongated polymer appears homogeneous and has a uniform thickness [53]. This observation is also reflected in the images derived from the PHB- and PLA-specific absorption bands. Furthermore, the orientation function of the PHB and PLA absorption bands is, over the whole area, negative and positive, respectively. 

If, on the other hand, the intensity of an absorption band exclusive of contributions due to the orientation of a highly elongated polymer is required for quantitative analysis, the so-called structural absorbance Ao has to be evaluated from polarization measurements ... 

Figure 19 An elongated polymer chain with ree / ee is viewed as a strongly stretched linear sequence of Pincus blobs.

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