Polylactic acid blends

Polymer blends have been categorized as (1) compatible, exhibiting only a single Tg, (2) mechanically compatible, exhibiting the Tg values of each component but with superior mechanical properties, and (3) incompatible, exhibiting the unenhanced properties of phase-separated materials (8). Based on the mechanical properties, it has been suggested that PCL-cellulose acetate butyrate blends are compatible (8). Dynamic mechanical measurements of the Tg of PCL-polylactic acid blends indicate that the compatability may depend on the ratios employed (65). Both of these blends have been used to control the permeability of delivery systems (vide infra). 

Microthermal analysis has been used in surface and depth profiling studies of PP [51,52], multi-block copolymers [53], polytetrafluoroethylene/silicone blends [14],PEG/polylactic acid blends [55], and PS/polyvinyl methyl ether blends [56]. See also Section 3.12. 

MTA has been nsed in surface and depth profiling studies on polypropylene (PP) [15, 16], multi-block copolymers [12], PTFE/silicone blends [13], polyethylene glycol (PEG) polylactic acid blends [17], PS-PVME blends [14] and PP [15]. 

FIGURE 12 Control of the rate of release of methadone from microspheres by the use of blends of a e-caprolactone-lactic acid copolymer and polylactic acid. (From Ref. 63.)... 

Silva et al. (2006) studied starch-based microparticles as a novel strategy for tissue engineering applications. They developed starch-based microparticles, and evaluated them for bioactivity, cytotoxicity, ability to serve as substrates for cell adhesion, as well as their potential to be used as delivery systems either for anti-inflammatory agents or growth factors. Two starch-based materials were used for the development of starch-based particulate systems (1) a blend of starch and polylactic acid (SPLA) (50 50 w/w) and (2) a chemically modifled potato starch, Paselli II (Pa). Both materials enabled the synthesis of particulate systems, both polymer and composite (with BG 45S5). A simple solvent extraction method was employed for the synthesis of SPLA and SPLA/BG microparticles, while for Pa and Pa/BG... 

The major classes of biopolymer, starch and starch blends, polylactic acid (PLA) and aliphatic-aromatic co-polyesters, are now being used in a wide variety of niche applications, particularly for manufacture of rigid and flexible packaging, bags and sacks and foodservice products. However, market volumes for biopolymers remain extremely low compared with standard petrochemical-based plastics. For example, biopolymer consumption accounted for just 0.14% of total thermoplastics consumption in Western Europe for 2005. 

Meanwhile, Fujitsu and Toray Industries have developed the first large-scale notebook computer housing based on polylactic acid biodegradable polymers. The housing is moulded of a specially developed PLA/polycarbonate blend that provide the required heat and flame resistance. 

Nodax can be blended with other biodegradable polymers such as polylactic acid and thermoplastic starch for improved processing performance. 

PEG, EVAc, EVAl, EPDM, PMMA, imidized-PMMA, SBR, PC, PSP, PI, PPE-blends, siloxanes, silicones, etc. Polylactic acid (PLA), polyglycolides, polybutyric acid or copolymers of butyric and valeric acid Kharas and Nemphos, 1992... 

Abstract The present chapter deals with a brief account on various types of natural polymers such as cellulose, chitin, starch, soy protein, casein, hemicellu-loses, alginates, polylactic acid and polyhydroxyalkanoates etc. Blends, composites and nanocomposites based on these polymers have been very briefly discussed. Finally the applications, new challenges and opportunities of these biomaterials are also discussed. 

Liao et al. [261] reported biodegradable nanocomposites prepared from poly(lactic acid) (PLA) or acrylic acid grafted poly(lactic acid) (PLA-g-AA), titanium tetraisopropylate, and starch. Arroyo et al. [262] reported that thermoplastic starch (TPS) and polylactic acid (PLA) were compounded with natural montmorillonite (MMT). The TPS can intercalate the clay structure and that the clay was preferentially located in the TPS phase or at the blend interface. This led to an improvement in tensile modulus and strength, but a reduction in fracture toughness. 

Polylactic Acid Based Blends, Composites and Nanocomposites... 

Anderson et al. [16] had performed melt blending on PLA/LLDPE in an effort to toughen PLA. The results indicated that, for the amorphous PLA, the toughening effect was achieved only when a polylactic acid-b-polyethylene (PLA-PE) block compolymer was used as a compatibilizer. They have reported that impact strength of 80/20 wt% PLA/LLDPE blend reach 35 15 kJm compare to the homopolymer (12 4 kJm ). They also showed that addition of 5 wt% of... 

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