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Crystalline sequence length

Using proton NMR of solutions, the composition of polymers can be analyzed.47 Carbon-13 NMR spectroscopy is a useful tool for studying the sequence length of segments in copolymers and thereby determining the blockiness of the copolymer. With solid-state NMR, the mobility of chain segments can be studied and the crystallinity determined. [Pg.162]

Figure 20.10 The effect of the blending time as a function of sequence length of the PET ( ) and PEN ( ) segments for the PHB/PEN/PET (40/30/30 (mol%)) blends [31]. From Park, J. K., Jeong, B. J. and Kim, S. H., Pseudo liquid crystallinity and characteristics of PHB/PEN/PET melt blend, Polym. (Korea), 24, 113-123 (2000). Reproduced by permission of The Polymer Society of Korea... Figure 20.10 The effect of the blending time as a function of sequence length of the PET ( ) and PEN ( ) segments for the PHB/PEN/PET (40/30/30 (mol%)) blends [31]. From Park, J. K., Jeong, B. J. and Kim, S. H., Pseudo liquid crystallinity and characteristics of PHB/PEN/PET melt blend, Polym. (Korea), 24, 113-123 (2000). Reproduced by permission of The Polymer Society of Korea...
Hydrolytic degradation of poly(e-CL)/PLLA block copolyester at pH 7.4 and 37 °C over a 5-week period is controlled by the initial crystallinity of the poly(e-CL) and its overall composition. The rate of degradation increased with increasing PLLA content [203 ]. Microorganisms, such as Fusarium solani and Fusarium moniliforme, that secrete poly(e-CL) depolymerase (cutinase), were more effective with those polymers that had longer poly(e-CL) sequence lengths [218]. The... [Pg.32]

The two parameters Pi and a i or their equivalents needed to determine the average sequence length of the isotactic crystallizable units can be determined from the melting temperature and the percent crystallinity of the polymer. The probability, P+( ), that a given sequence of -l- s is exactly of length is ... [Pg.90]

Davison,S., Taylor,G.L. Sequence length and crystallinity in alpha-olefin terpolymers. Brit. Polymer J. 4, 65-82 (1972). [Pg.126]

NMR not only yields chemical information, but can also be used to analyze polymer tacticity, sequence lengths, short-chain branching, and crystallinity. [Pg.118]

In principle, the same effects are observed on dissolving crystalline helical polymers. In addition, the interaction of the solvent with the polymer may be observed, as well as changes in the population and sequence lengths of conformations caused by this interaction. Two limiting cases may be distinguished according to the strength of the interaction ... [Pg.106]

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See also in sourсe #XX -- [ Pg.147 ]



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Sequence length

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