Poly extenders

Scheuermann, T., Schulz, B., Blume, A., Wahle, E., Rudolph, R., and Schwarz, E. (2003). Trinucleotide expansions leading to an extended poly-L-alanine segment in the poly (A) binding protein PABPN1 cause fibril formation. Protein Sci. 12, 2685-2692. 

Bikiaris, D. N. and Karayannidis, G. P., Calorimetric study of diepoxide chain-extended poly(ethylene terephthalate), J. Therm. Anal. Calorim., 54, 721 (1998). 

In principle, bifunctional aldehydes should be able to engage in twofold enzymatic aldol additions to both of their acceptor carbonyls in a fashion to be classified as a tandem reaction, that is, without the need for isolation of intermediates. Depending on the specificity of the enzyme used and on the functionalization in the starting material, the isomeric constitution as well as the absolute and relative stereochemistry should be deliberately addressable. Therefore, we engaged in a program to evaluate the scope and the Hmitations of such two-directional chain elongation processes for the construction of extended poly functional molecules [36]. 

Garret, J. T., X. Ruijian, J. Cho, and R. James. "Phase Separation of Diamine Chain Extended Poly(Urethane) Copolymers FTIR Spectroscopy and Phase Transions." Polymer 44 (2003) 2711-2719. 

The range of polymers which were found to be able to form liquid crystalhne systems has been considerably extended. Poly(Y-benzyl-L-glutamate) and its analogs, as well as para-aromatic polyamides, exhibit this property in solutions, which served the basis for relating them to lyotropic liquid crystals (see Sect. 2.1). Subsequently, the classes of polymers were found which exhibited such a transition during a change of temperature thermotropic liquid crystals). 

Tserki, V, Matzinos, R, Pavlidou, E. and Panajdotou, C. (2006) Biodegradable aliphatic polyesters. Part II. Synthesis and characterization of chain extended poly(butylene succinate-co-butylene adipate). Polymer Degradation and Stability, 91 (2), 377-384. 

Taniguchi I, Nakano S, Nakamura T, El-Salmawy A, Miyamoto M, Kimura Y (2002) Mechanism of enzymatic hydrolysis of poly(butylene succinate) and poly(butylene succinate-co-L-lactate) with a lipase from Pseudomonas cepacia. Macromol Biosci 2 447-455 Tomita K, Kuroki Y, Hayashi N, Komukai Y (2000) Isolation of a thermophile degrading poly(butylene succinate-co-butylene adipate). J Biosci Bioeng 90 350-352 Tserki V, Matzinos P, PavUdou E, Panayiotou C (2(X)6a) Biodegradable aliphatic polyesters. Part II. Synthesis and characterization of chain extended poly(butylene succinate-co-butylene adipate). Polym Degrad Stab 91 377-384... 

These data- and control-flow transformations are based on an extended poly-hedral dependence graph (PDG) model [23] (see also chapter 7), in terms of which the actual optimization problem is defined and the transformations are performed. In this section, a short overview is given of the main concepts of the PDG. Detailed information can be found elsewhere [23, 22]. 

There are also other inexpensive diisocyanates like NDI, produced on a smaller scale. In early works, Bayer et al [57] showed that NDI exhibited excellent physical properties in water extended poly(ethylene adipate) (PEA) based elastomers, due to the rigid naphatalene structure. However, this polymer has poorer stability at high temperature (it decomposes above 150 C). 

Garrett JT, et al. Phase separation of diamine chain-extended poly(urethane) copolymers FTIR spectroscopy and phase transitions. Polymer 2003 44(9) 2711-9. 

Hariraksapitak, P, Suwantong, O., Pavasant, P, Supaphol, P., 2008. Effectual drug-releasing porous scaffolds from 1,6-diisocyanatohexane-extended poly( 1,4-butylene succinate) for bone tissue regeneration. Polymer 49, 2678-2685. 

Garrett, J. T., Lin, J. S., Runt, J. (2002), Influence of preparation conditions on microdomain formation in poly(urethane urea) block copolymers. Macromolecules, 35,161-8. Garrett, J. T., Xu, R., Cho, J., Runt, J. (2003), Phase separation of diamine chain-extended poly(urethane) copolymers FT-IR spectroscopy and phase transitions. Polymer, 44, 2711-19. 

Fig. 15. Segment of an extended poly(propylene) chain. The overall geometry of the molecule depends both on the configuration (mrmmr) and the conformation (t%) (a). The relevant conformational statistics is determined by considering the central part of an extended polymer chain (b). The statistical weight of a chain molecule with a fixed configuration Xf is determined by multiplying the appropriate RIS weight matrices. The weight matrices depend on the configuration.

Application of ROPA reaction for chain extender The highly reactive nature of ROZO toward carboxylic acid group was applied for a chain extender. Poly(ethylene terephthalate) (PET) is an important plastics as it is widely used in daily life. The annual consumption is over 10 million tons worldwide. 

Fig. 2. Schematic model of extended poly(l-vinylnaphthalene) with triplet donor molecules M (O ). 2 denotes a naphthalene moiety and hiT the incident photon absorbed by M. M inter system crosses before transferring its excitation energy to pendent groups.

Niesten M C E J, ten Brinkel J W and Ca5mans R J (2001) Segmented copolyether-esteraramids with extended poly(tetramethyleneoxide) segments, Polymer 42 1461-1469. 

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