PCL/PLA blends

Similar to Wu and Liao (75), Wu et al. (74) used a DMA (Model -242C, NETZSCH Co.) and a rheometer (HAAKE RS600, Thermo Electron Co.) to evaluate the viscoelastic behavior of the carboxylic-acid-functionalized MWCNTs reinforced PCL/PLA blend. Using DMA, it was observed that, with the increase of MWCNT loading, the Tg of the blend system shifted to higher temperatures. This agrees with the results obtained from the other studies discussed above and indicates the MWCNTs are compatible with the blend. The viscoelastic properties observed via rheometer were similar to those by Wu et al. (73), discussed above. 

Patricio, T. and Bdrtolo, P. (2013) Thermal stability of PCL/PLA blends produced by physical blending process. Procedia Eng., 59, 292-297. 

Wu et al. [126] used functionalized MWCNTs to control the morphology of immiscible PCL/PLA blend. It was found that the MWCNT selectively dispersed in the PCL phase, leading to the simultaneous occurrence of thermodynamically and kinetically driven compatibility. This study followed their initial work where purified CNT was used [126,127]. 

Copolymerization offers considerable potential of engineering the properties and degradation rate of PHB over a broad range. HB has been copolymerized with a number of related species, e.g., e-CL, LA, 4-hydroxybutyrate and hydrox-ypropionate. Furthermore, a number of PHB blends have been prepared. Miscibility of PHB with PCL, PLA, POE, poly(mandelic acid), and poly(sebacic anhydride) has been demonstrated. PHB-poly(sebacic anhydride) blends offered controlled release of bupivacaine at a rate dependent on the PHB content [141]. Blending of P(HB-co-HV) with natural polysaccharides was proposed as a way... 

It is known that PLA forms miscible blends with polymers such as PEG [53]. PLA and PEG are miscible with each other when the PLA fraction is below 50 per cent [53]. The PLA/PEG blend consists of two semi-miscible crystalline phases dispersed in an amorphous PLA matrix. PHB/PLA blends are miscible over the whole range of composition. The elastic modulus, stress at yield, and stress at break decrease, whereas the elongation at break increases, with increasing polyhydroxybutyrate (PHB) content [54]. Both PLA/PGA and PLA/PCL blends give immiscible components [55], the latter being susceptible to compatibilization with P(LA-co-CL) copolymers or other coupling agents. 

TCH of 5 wt%/v was dissolved in methanol using an orbital shaking incubator, and then was mixed with polymer blend solutions (8wt%/v PLA mixed with 9 and 15wt%/v PCL at blend ratio of 1/1 by volume). The TCH-loaded fiber mats were cut into size of 2 cm X 2 cm and underwent a rotary shaker incubation (rotor... 

Chitosan, a natural polymer derived from chitin, has application in edible coatings or films for packaging foodstuffs, but its use is limited by its high sensitivity to moisture. Its ability to form a water barrier can be improved by blending with a more hydrophobic polymer also derived from natural resources, such as PLA. Blends of starch with PCL can be reinforced with nanoscale platelets derived from smectic clay to significantly increase film ductility and barrier properties. 

PCL/PLA 70/30 MWCNT and carboxylic MWCNT PCL phase and interface Unfunctionalized MWCNT is located exclusively in the PCL phase, while carboxylic MWCNT is located in the PCL phase and at the interface. The reinforcing and compatibilization effect of nanotubes results in a higher improvement in electrical conductivity and mechanical properties compared to pure blend. Improved phase stability and lower rheological and electrical conductivity percolation threshold were observed Wu et al. 2009... 

The use of nanoclays to improve the barrier properties of PLA blends was investigated by Plackett and Soder-gard [113], who blended PLA with PCL and added nanoclays. A significant reduction in O2 and water permeability was observed with the incorporation of nanoclays. Furthermore, these authors concluded that it is more difficult to achieve target permeability values using nanoclays if the nanoclays are combined with impact modified PLA. 

The effects of uncoated or coated polymeric microspheres made from blends of PEVAc/PLA (50/50) on the activation of neutrophils causing some localized inflammation compared to three types of pristine polymers (PLA, PCL, and polymethyl methacrylate (PMMA)) were investigated by Jackson et al. [62]. The neutrophil activation induced by polymers and polymer blends was very low, and among plasma-coated microspheres, PEVAc/PLA blend exhibited the lowest activation, whereas among immunoglobufin-coated microspheres, the blend had the highest activation [62]. 

Poly(e-caprolactone)/PLA Blends Poly( -caprolactone) (PCL) is a water-insoluble biodegradable, petroleum-based aliphatic polyester synthesized by ringopening polymerization of -caprolactone (e-CL) [81, 82]. PCL blends are widely used in many applications such as compostable bags for yard waste or other organics collection, disposable food service items, food packaging, health care products, mulch films in agriculture, and adhesives [81, 82, 101-103]. The nontoxicity, biocompatibility. 

---