Synthesis of Fatty Acid-Based Polyesters and Their Blends with Poly(L-lactide) as a Way To Tailor PLLA Toughness

10.1021/sc500648gInternational audiencePolylactide (PLA) is one of the most mature biobased and biocompostable plastics currently in the market. Despite its mechanical properties comparable to the ones of some mainstream petroleum-based thermoplastics (PS, for instance), PLA inherent brittleness and heat sensitivity are issues for its full industrial development. In this study, we investigated the melt-blending of PLLA (poly-L-lactide) with fatty acid-based flexible polyesters as an efficient way to tailor PLLA toughness. To that aim, a set of aliphatic polyesters has been developed by taking benefit of the large range of biobased building blocks that can be obtained from plant oils. Melt-blending of the so-formed polyesters with PLLA resulted in improved properties that can be finely tailored by varying the structure and the properties of the plant-based polyester additives

Matériaux hybrides nanostructurés incorporant des entités chirales ou ioniques (Synthèse et application)

MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Ionic liquids incorporating camphorsulfonamide units for the Ti-promoted asymmetric diethylzinc addition to benzaldehyde

International audienceNew hydrophobic ionic liquids containing chiral camphorsulfonamide units were used as chiral auxiliaries in the titanium catalyzed asymmetric diethylzinc addition to benzaldehyde. The ionic catalyst system shows catalytic properties similar to those of related nonionic counterparts in terms of activity and enantioselectivity. Interestingly, the ionic ligands can easily be recycled and re-used without loss of activity or selectivity

AB type polyaddition route to thermoplastic polyurethanes from fatty acid derivatives

Naturally occurring oleic acid and undecylenic acid derivatives were successfully utilized to synthesize a series of new semi-crystalline polyurethanes via the AB-type polycondensation approach. A set of four novel AB-type monomers was prepared via the use of environmentally benign thiol-ene chemistry. These AB-type monomers were self-polycondensed (with or without catalyst) in two ways: (a) the hydroxyl-acyl azide approach and (b) the melt transurethane method in order to obtain reasonably high molar mass polyurethanes. The resulting polymers were thoroughly characterized by NMR, SEC, DSC, TGA and MALDI-TOF mass spectroscopy. The MALDI-TOF analysis confirmed the formation of linear polyurethanes with a trace amount of macrocycles. All the polyurethanes exhibited fair thermal stability with no significant weight loss below 200 degrees C. The polyurethanes based on undecylenic acid as a monomer displayed a thermoplastic behavior with well-identified melting transitions. Further, DSC analysis revealed that polyurethanes prepared from undecylenic acid by different methods showed different glass and melting transitions. Two glass transition temperatures due to soft and hard segments were observed for polyurethanes synthesized from oleic acid derivatives, indicating a phase-separated morphology

Anionic Polymerization of Butadiene Using Lithium/Potassium Multi-metallic Systems: Influence on Polymerization Control and Polybutadiene Microstructure

International audienc

Fully bio-based poly(L-lactide)-b-poly(ricinoleic acid)-b-poly(L-lactide) triblock copolyesters: investigation of solid-state morphology and thermo-mechanical properties

In this work, a set of ABA triblock poly(L-lactide)-b-poly(ricinoleic acid)-b-poly(L-lactide) aliphatic copolyesters were prepared by consecutive AB type self-condensation and ring-opening polymerization. Condensation of methyl ricinoleate, produced from castor oil, in the presence of a small amount of 1,3-propanediol afforded alpha,omega-hydroxy-terminated poly(ricinoleic acid) with a molar mass of 11 kg mol(-1). Polymerization of L-lactide initiated from the terminal hydroxyl moieties of the alpha,omega-hydroxy-terminated poly(ricinoleic acid) led to triblock copolymers with a composition ranging from 35 to 83 wt% of PLLA. The block structure was confirmed by several techniques. The copolymers displayed a multi-step thermal degradation with a temperature corresponding to 5 wt% loss in the range 175-225 degrees C. DSC analyses showed that the PRic block had a moderate effect on PLLA melting behavior. The solid-state morphology of the so-formed copolymers was highly dependent on their chemical composition, as evidenced by SAXS and WAXD analyses. The high degree of separation of hard and soft phases was also confirmed by dynamic mechanical analysis as seen from the distinct alpha-relaxations. Finally, the tensile properties of these block copolymers ranged from thermoplastic to elastomeric depending on their composition

Solubility in CO(2) and carbonation studies of epoxidized fatty acid diesters: towards novel precursors for polyurethane synthesis

Novel linear polyurethanes were synthesized by bulk polyaddition of diamines with two vegetable-based biscarbonates produced from oleic acid methyl ester. Internal carbonated fatty acid diester (ICFAD) and terminal carbonated fatty acid diester (TCFAD) were obtained by the reaction of their epoxide precursors with CO(2). Terminal epoxy fatty acid diester (TEFAD) was found to be more soluble and more reactive in CO(2) than internal epoxy fatty acid diester (IEFAD). Polyurethanes obtained by polyaddition of TCFAD and ICFAD with diamines exhibit molecular weights up to 13 500 g mol(-1) and glass transitions around -15 degrees C. Amide linkages were not observed when secondary diamine was used as the comonomer

Ring opening of epoxidized methyl or ethyl oleate by alkyl glycosides

International audienc

Novel fatty acid based di-isocyanates towards the synthesis of thermoplastic polyurethanes

Fatty acid derivatives have been successfully transformed into diisocyanates via a non-phosgene and green method. The structure of these novel diisocyanates was confirmed through FTIR and H-1 NMR spectroscopies. These diisocyanates were reacted with commercially available and fatty acid based diols to obtain partially and fully bio-based polyurethanes respectively. The selected diols were of various structural features: with linear methylene spacers from 3 to 12 units, with sulfur-containing unit, ester linkages or cyclo-aliphatic units. The polyurethanes obtained were thoroughly characterized by FTIR, H-1 NMR spectroscopy, SEC studies, DSC and TGA experiments. Most of the polyurethanes were semi-crystalline in nature with well-identified melting transitions. However, due to plasticization and/or conformational issues, insertion of methylene dangling chains or cyclic moieties imparted amorphous feature to the polyurethanes. The polyurethanes displayed fair thermal stability with no significant weight loss below 235 degrees C

Aliphatic polycarbonates and poly(ester carbonate)s from fatty acid derived monomers

Fatty acid derivatives were efficiently used as starting materials for the synthesis of polycarbonates and poly(ester carbonate)s. A novel AB-type self-condensable monomer, ethyl(9-hydroxy-10-methoxyoctadecyl)carbonate (EHMOC) and a dicarbonate monomer, 4-[(ethoxycarbonyl)oxy]butyl-12-[(ethoxycarbonyl)oxy]octadec-9-enoate (EOBEOE) were prepared from oleyl alcohol and ricinoleic acid, respectively. Of these, EHMOC was polymerized by the alcohol-carbonate exchange self-polycondensation approach, while EOBEOE was polycondensed with various biobased diols to give polycarbonates and poly(ester carbonate) s, respectively. The monomers and polymers were well characterized by FTIR and H-1-NMR spectroscopy. The C-13-NMR spectroscopy revealed the formation of randomly distributed sequences in the poly(ester carbonate) s due to the carbonate interchange reaction. An unexpected formation of polyricinoleate was observed and confirmed by NMR and MALDI-TOF spectroscopy. Most of the polymers displayed good thermal stability with the temperature at 10% weight loss in the range 273-325 degrees C. Due to the presence of aliphatic segments, these materials exhibit very low glass transition temperature