Poly lactide s

Lactic acid based polymers manufactured by melt processing are blow molded bottles, injection molded cups, spoons, and forks. Other applications include paper coatings, fibers, films, and various medical devices. 

The hydrolysis of the polymers leads to molecular fragmentation. The hydrolytic degradation of lactic acid based polymers is an undesired phenomenon under certain circumstances, such as during processing or material storage. It is however, beneficial in other applications, for example in medical devices or compostable packages (12). 

In branched poly(lactide)s, the enzymatic degradability and the hydrolytic degradation increase with the branches present in the molecule (13). 

In conclusion, I have shown that the mechanism of stabilization has been investigated by allowing to react the carbodilmide with various model substances, e.g., water, acetic acid, etiianol. The structure of the products of solvolysis has also been elucidated. It has also been demonstrated that the carbodiimide reacts with residual or newly formed moisture and lactic acid, or the carboxyl and hydroxyl end groups in the PLA. These groups are hampering the thermal degradation and hydrolysis of PLA. 

Takahashi, H. lida, and N. Nakamura, Carbodiimide composition with suppressed yellowing, a stabilizer against hydrolysis and a thermoplastic resin composition, US Patent 7 368 493, assigned to Nissh-inbo Industries, Inc. (Tokyo, JP), May 6,2008. 

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Tsuji, H., Kamo, S. Horii, F. (2010). Solid-state i C NMR analyses of the structures of crystallized and quenched poly(lactide)s Effects of crystallinity, water absorption, hydrolytic degradation, and tacticity. Polymer, Vol. 51, No. 10, pp. 2215-2220... 

A.J. Cross, M.G. Davidson, D. Garda-Vivo, T.D. James, Well-controlled synthesis of boronic-add functionalised poly(lactide)s a versatile platform for hiocompatible polymer conjugates and sensos. RSC Adv. 2 (2012) 5954, doi 10.1039/c2ra20373a. 

Tsuji, H., Shimizu, K., Sakamoto, Y. and Okumura, A. (2011) Hetero-stereocomplex formation of stereoblock copolymer of substituted and non-substituted poly(lactide)s. Polymer, 52, 1318-1325. 

Brizzolara, D., Cantow, H.-J., Diederichs, K. et al. (1996) Mechanism of stereocomplex formation between enantiomeric poly(lactide)s. Macromolecules, 29, 191-197. 

Bouapao, L., Xsuji, H., Xashiro, K. etal. (2009) Crystallization, sphemlite growth, and structure of blends of crystalline and amorphous poly(lactide)s. Polymer, 50, 4007 017. 

Tsuji, H. and Ikada, Y. (1996) Crystallization from the melt of poly(lactide)s with different optical purities and their blends. Macromolecular Chemistry and Physics, 197,3483-3499. 

Tsuji, H., Okino, R., Daimon, H. and Fujie, K. (2006) Water vapor permeability of poly(lactide)s Effects of molecular characteristics and crystaUinity. Journal of Applied Polymer Science, 99,2245-2252. 

Tsuji, H. and Del Crirpio, C.A. (2(X)3) In vitro hydrolysis of blends from enantiomeiic poly(lactide)s. 3. Homo-crystaUized rmd amorphous blend films. Biomacromolecules, 4,7-11. 

Tsuji, H. (2000) In vitro hydrolysis of blends from enantiomeric poly(lactide)s. 1. WeU-stereocomplexed blend and non-blended films. Polymer, 41, 3621-3630. 

Tsuji, H. and Fukui, I. (2003) Enhanced thermal stability of poly(lactide)s in the melt by enantiomeric polymer blending. Polymer, 44, 2891-2896. 

Poly(ether-carbonate) copolymers Poly(lactide)s 250 RU" 12-14 295 [13]... 

Biodegradable pol5miers can be synthesized using renewable resources by conventional methods (13). For example, yttrium complexes are suitable compounds for the S5mthesis of poly(lactide)s. 

Some of these pol miers and copolymers do not possess the mechanical properties that are required for certain applications. For example, as implants for soft tissue poly(lactide)s, poly(glycolide)s, PCL, poly(dioxanone) and their copolymers may require increased flexibiUty and a modulus of elasticity that is closer to soft tissue. 

The initiators 45-PrOH and 45-PrE were then used to polymerize cyclic ester and styrenic monomers to give poly(lactide)s 51-pL and polystyrene 51-pS, respectively. Both polymerizations were observed under reasonable control over the molecular weight and chemical nature of the arms. Preliminaiy results demmi-strated that these polymers are capable of forming a host-guest complex with Ceo-... 

Li, S., McCarthy, S.P., 1999b. Influence of crystallinity and stereochemistry on the enzymatic degradation of poly(lactide)s. Macromolecules 32, 4454—4456. Reprinted with permission. 

H. Tsuji, R. Okino, H. Daimon and K. Fujie, Water vapor permeability of poly (lactide)s effects of molecular characteristics and crystallinity, J. Appl. Polym. Sci., 99 (2006) 2245-2252. 

When the vine-twining polymerization was conducted using optically active polyesters, poly(lactide)s (PLAs), which had three kinds of the stereoisomers, i.e., poly(L-lactide) (PLLA), poly(D-lactide) (PDLA), and poly(DL-lactide) (PLDLA), as guest polymers, the author found that amylose, produced by the enzymatic polymerization, perfectly recognized the chirality in PLAs on complexation and... 

Radke W, Rode K, Gorshkov AV, Biela T. Chromatographic behavior of functionalized star-shaped poly(lactide)s under critical conditions of adsorption. Comparison of theory and experiment. Polymer 2006 46 5456-65. 

In biodegradable plastics, e.g., polyesters or poly(lactide)s, special monomers are used that can easily be metabolized by microorganisms. In general, in a biodegradable plastic, biodegradation proceeds by the following processes (1) ... 

Tsuji H, Ikada Y. Blends of isotactic and atactic poly(lactide)s 2 Molecular-weight effects of atactic component on crystallization and morphology of equimolar blends from the melt. Polymer 1996 37 595-602. 

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