Immiscible binary blends of poly(l,l-lactide) (PLLA), and poly(1-caprolactone) (PCL), with 90/10, 80/20 and 70/30 wt% compositions, as well as ternary PLLA/PCL blends containing 0.5±5 wt% of a triblock PLLA/PCL/PLLA copolymer, were obtained by melt mixing using a twin screw extruder. Optical microscopy investigation of binary blends revealed the immiscibility of the components. The thermal behaviour of the blends was investigated by DSC and DMTA and compared with that of pure PLLA. The PLLA crystallization rate was enhanced in the presence of PCL domains. Morphological analysis of the cryofractured and etched±smoothed surfaces was carried out by SEM on both binary and ternary blends. A dimensional analysis of the PCL domains in binary and ternary blends was also performed in order to evaluate the in¯uence of the presence of the triblock copolymer on the dispersion mode of PCL in the PLLA matrix. q

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SUMMARY: A binary poly(L-lactide)/poly(e-caprolactone) (PLLA/PCL) a (70/30 w/w) blend and a ternary PLLA/PCL/PLLA-PCL-PLLA blend of the same composition which contains 4 wt.-% of a triblock PLLA-PCL-PLLA copolyester as compatibilizing agent were prepared by melt mixing at 200 8C. Investigation of the thermal and mechanical properties of the blends and scanning electron microscopy of their fracture surfaces showed in the case of the ternary blend a better state of dispersion of PCL in the PLLA matrix and an improved toughness.

Summary: A binary blend of poly (L‐lactide) (PLLA) and poly(ε‐caprolactone) (PCL) of composition 70:30 by weight was prepared using a twin screw miniextruder and investigated by differential scanning calorimetry (DSC), optical microscopy and scanning electron microscopy (SEM). Ternary 70:30:2 blends were also obtained by adding either a diblock copolymer of PLLA and poly(oxyethylene) (PEO) or a triblock PLLA‐PCL‐PLLA copolymer as a third component. Optical microscopy revealed that the domain size of dispersed PCL domains is reduced by one order of magnitude in the presence of both copolymers. SEM confirmed the strong reduction in particle size upon the addition of the copolymers, with an indication of an enhanced emulsifying effect in the case of the PLLA‐PEO copolymer. These results are analyzed on the basis of solubility parameters of the blend components.Optical micrograph of M3EG2 blend melt quenched at 125 °C.imageOptical micrograph of M3EG2 blend melt quenched at 125 °C.

In this work, the problem of grasping novel objects with an anthropomorphic hand-arm robotic system is considered. In particular, an algorithm for learning stable grasps of unknown objects has been developed based on an object shape classification and on the extraction of some associated geometric features. Different concepts, coming from fields such as machine learning, computer vision, and robot control, have been integrated together in a modular framework to achieve a flexible solution suitable for different applications. The results presented in this work confirm that the combination of learning from demonstration and reinforcement learning can be an interesting solution for complex tasks, such as grasping with anthropomorphic hands. The imitation learning provides the robot with a good base to start the learning process that improves its abilities through trial and error. The learning process occurs in a reduced dimension subspace learned upstream from human observation during typical grasping tasks. Furthermore, the integration of a synergy-based control module allows reducing the number of trials owing to the synergistic approach.