Abstract. Improving overall properties of poly(lactic acid) (PLA) by blending it with another biobased polymer has been a strong field of research over the last years. In this study we demonstrate the synergetic effect of a small amount (between 0.1 and 1 wt%) of oligomer-like PLA (oLA) on the thermal, mechanical and gas barrier properties of the widely studied PLA-poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) blends (90-10 wt%). Films of PLA/PHBV/oLA blends were prepared via single-screw extrusion. oLA being miscible with both PLA and PHBV, its compatibilizing effect was demonstrated by a decrease of the interfacial tension, a slight shift in the T g s of both polymers, and an increase in the elongation at break. It was also showed that oLA had a plasticizing effect on the PHBV dispersed phase, increasing its crystallinity rate. This resulted in a decrease in the permeability of the films while improving Young's modulus.

The crosslinking of poly(dimethylsiloxane) elastomers and coatings by the thermal curing of poly(dimethylsiloxane‐co‐methylvinylsiloxane) and 1,12‐diazido‐dodecane was studied. This crosslinking pathway relies on the cycloaddition of azides and alkenes as well as the thermal generation of nitrene transient radicals, which react with alkenes, yielding respectively 1,2,3‐triazoline and aziridine crosslinking knots. The influence of temperature and the ratio of azide and vinyl functionalities has been investigated by rheological, swelling, and insoluble fraction measurements for materials crosslinked in bulk and by comparison of the thickness before and after extraction of the soluble materials by soxhlet extraction for the crosslinked coatings. The preparation of highly crosslinked PDMS‐based elastomers and coatings has been demonstrated, even if the fraction of elastically effective crosslinks in bulk remained below 160 mol/m3. Advantageously, this system does not require additional initiator or catalyst, is not sensitive to moisture or oxygen, and can be extended to a wide range of unsaturated polymers as well as different organic or inorganic solid substrates. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Thermoreversible polyurethane networks were successfully prepared by Diels-Alder reaction using a highly maleimidefunctionalized urethane prepolymer with an epoxy-based furan coupling agent or a furan-functionalized polyurethane. Highly functional maleimide prepolymers with various functionalities were synthesized by the isocyanate-alcohol reaction from glycerol, H 12 MDI, and protected N-hydroxymethylmaleimide. Thermal behavior and de-crosslinking of the networks were studied via thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and solubility tests. Swelling tests allowed the evaluation of the networks' density. Thermal properties and crosslinking density were influenced by furan and maleimide functionalities and by the nature of the diene. Denser networks with lower de-crosslinking temperatures were obtained using the epoxy-based furan coupling agent. With the furan-functionalized polyurethanes, looser networks and higher de-crosslinking temperatures were obtained. These higher de-crosslinking temperatures were attributed to the presence of more physical links in the networks.