Synthesis of branched poly(butylene succinate): Structure properties relationship

International audience; A series of branched poly(butylene succinate) (PBS) were synthesized with several branching agents namely trimethylol propane (TMP), malic acid, trimesic acid, citric acid and glycerol propoxylate. The structure of the branched polymers was analyzed by SEC and H-1-NMR. The effect of branching agent structure on crystallization was also investigated and played a significant role. Isothermal studies showed that glycerol propoxylate could act as a nucleating agent. By contrast high content of TMP disturbed the regularity of the chain and hindered the crystallization of PBS. From the non-isothermal kinetic study, it was found that glycerol propoxylate increased noticeably the crystallization rate due to the flexible structure of the branching agent. A secondary nucleation was observed with glycerol propoxylate attributed to the crystallization of amorphous fraction included between crystallites formed at the primary crystallization. Chain topology was obtained through rheological investigations and the synthesized polymers showed a typical behavior of a mixture of linear and randomly branched PBS. The incorporation of branches improved the processability of PBS for film blowing application and the modulus and the stress at break of the resulting film were significantly increased

Synthesis of Poly[(ethylene terephthalate)-co- (e-caprolactone)]-Poly(propylene oxide) Block Copolyester by Direct Polyesterification of Reactive Oligomers

International audienceThe objective of this study was to synthesize thermoplastic elastomers by the direct copolyesterification of reactive oligomers of poly[(ethylene terephthalate)-co-(ecaprolactone)] (PET) and poly(propylene oxide) (PPO). The synthesis of hard segment oligomers was achieved in two steps. The first step consisted of the glycolysis of PET leading to a,o-hydroxyl functionalized oligomers. The second step corresponded to the ring opening polymerization of e-caprolactone onto the hydroxyl end groups of thePEToligomers. Commercially available hydroxytelechelic poly(propylene oxide) was modified to obtain carboxytelechelic poly(propylene oxide). The chemical structure of the product was investigated by 1H NMR and size exclusion chromatography (SEC). Multiblock poly(ester-ether) was then synthesizedbypolyesterificationofhydroxytelechelicpoly[( ethylene terephthalate)-co-(e-caprolactone)] with carboxytelechelic poly(propylene oxide) oligomers, using different catalysts and reaction conditions. The best stoichiometric ratio for the reaction was determined in order to obtain the highest possible Mn. The chemical structure of the synthesized poly(ester-ether) was investigated by size exclusion chromatography and 1H NMR. The thermal and thermomechanical behavior of the synthesized poly(ester-ether) was investigated by differential scanning calorimetry and dynamic mechanical analysis, which showed that the poly(ester-ether) behaved as a thermoplastic elastomer. This product could also be an interesting way for chemical recycling of PET waste

Recyclage chimique du poly(éthylène téréphtalate). Application à la synthèse d'élastomères thermoplastiques

MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Synthesis and Characterization of New Thermosetting Polyurethanes coatings obtained from Biobased Dihydroxytelechelic Oligocarbonates

International audienc

Isothermal Crystallization Kinetics of Poly(ethylene terephthalate) Copolymerized with Various Amounts of Isosorbide

Poly(ethylene-co-isosorbide terephthalate) (PEIT) copolyesters could be used in various applications depending on their ability to crystallize. Moreover, the possibility to carry out solid-state post-condensation (SSP) is conditioned by its ability to sufficiently crystallize. The present study, thus, gives a systematic investigation of isothermal crystallization of these statistical copolyesters with isosorbide contents ranging from 4.8 to 20.8 mol.%. For each copolyester composition, the lowest isothermal half crystallization times and the highest Avrami constant (K) were obtained around 170 °C. Over the range of composition that was studied, both melting points and melting enthalpies decreased with increasing amounts of isosorbide (from 250 to 207 °C and from 55 to 28 J/g, respectively). On the contrary, half crystallization time displayed an exponential increase when increasing isosorbide contents in the studied range. Finally, structural and thermal analysis of PIT homopolyester are reported for the first time, showing that only ET moieties crystallized when PEIT was subjected to isothermal crystallization at 170 °C

New Cure – Study of the carbamate-aldehyde reaction : toward new thermosetting resins

International audienc

Bio-based alternatives in the synthesis of aliphatic-aromatic polyesters dedicated to biodegradable film applications

International audienceThe pilot scale synthesis of poly(butylene succinate) copolymers with rigid bin-based comonomers, namely isosorbide and 2,5-furandicarboxylic acid (FDCA) was investigated. The synthesis and properties of these copolymers were compared with aliphatic-aromatic polyesters containing the petrochemical terephthalic acid (PTA), such as poly(butylene succinate-co-terephthalate) (PBST) and commercial poly(butylene adipate-co-terephthalate) (PBAT). Compared to PBS, polycondensation was much faster with up to 20 mol% of FDCA in the feed whereas polycondensation rate was negatively affected for isosorbide and terephthalic acid modified PBS. These phenomena were attributed to the low reactivity of the isosorbide secondary endo hydroxyl function for poly(butylene-co-isosorbide succinate) (PBIS) and to kinetic effects for poly(butylene succinate-co-terephthalate) (PBST). The H-1 NMR analyses of triads of PBST and poly(butylene succinate-co-furanoate) (PBSF) were typical of random copolyesters. The thermal properties of the polymer materials showed an increase in the glass transition temperature from -30 degrees C for PBS up to -11 degrees C for PBS that contained 14 mol% isosorbide. The ability of the copolymer to crystallize was drastically reduced with the addition of the comonomer; this trend was observed to a smaller extent for PBST. This low crystallinity had as a consequence an important increase in the elongation at break of the polymer. PBSF samples with FDCA tested here were found to be compostable according to EN 13432

Polymers from renewable 1,4:3,6-dianhydrohexitols (isosorbide, isomannide and isoidide): A review

International audienceThe use of 1,4:3,6-dianhydrohexitols, isosorbide, isomannide and isoidide in polymers is reviewed. 1,4:3,6-Dianhydrohexitols are derived from renewable resources from cereal-based polysaccharides. In the field of polymeric materials, these diols are essentially employed to synthesize or modify polycondensates. Their attractive features as monomers are linked to their rigidity, chirality, non-toxicity, and the fact that they are not derived from petroleum. First, the synthesis of high glass transition temperature polymers with good thermomechanical resistance is possible. Second, the chiral nature of 1,4:3,6-dianhydrohexitols may lead to specific optical properties. Finally, biodegradable polymers can be obtained. The production of isosorbide at the industrial scale with a purity satisfying the requirements for polymer synthesis suggests that isosorbide will soon emerge in industrial polymer applications. However, a deciding factor will be the reduction of polymerization time of these low-reactivity monomers to values compatible with economically viable production processes. (C) 2009 Elsevier Ltd. All rights reserved

Study of the carbamate/aldehyde reaction, a new pathway towards NIPU materials

International audienceAn innovative alternative to the synthesis of non-isocyanate polyurethanes (NIPUs) thermoset materials was thoroughly investigated. This pathway, involving the reaction between primary carbamate functions and aldehyde functions, was studied using model reactions between ethyl carbamate and different aldehydes that lead to the highlights of the key parameters as well as the first reported proposed mechanism for this reaction. In a second time, polycarbamates synthesized from two different polyols were synthesized via transcarbamoylation before participating in a polycondensation reaction with different monoaldehydes. First a linear NIPU oligomer was synthesized using a dicarbamate derived from ethylene glycol and benzaldehyde. This product was analyzed by NMR spectroscopy and MALDI-TOF mass spectrometry. This oligomer exhibited low molar masses attributed to many secondary termination reactions, mainly due to the presence of acetic anhydride used as solvent in the reaction. Cross-linked NIPU materials were then synthesized without solvent, from the reaction between a tricarbamate derived from trimethylol propane and vanillin, a biobased monoaldehyde, for the first time. The process parameters for the synthesis of these materials were optimized to obtain biobased NIPU thermosetting networks with gel fraction (GF) in dimethylsulfoxide (DMSO) up to 82%, with Tg values ranging between 39°C and 65°C depending on the GF value. This study brings a much needed highlight on the little-known carbamate / aldehyde reaction and demonstrates its potential for the synthesis of novel biobased NIPU thermosetting coatings using a simple monoaldehyde such as vanillin

New Cure – Study of the carbamate-aldehyde reaction : toward new thermosetting resins

International audienc