Carbon Tetrachloride as Thermoporometry Liquid-probe to Study the Cross linking of Styrene Copolymer Networks

Mesh Size Distributions (MSDs) of swollen cross linked styrene copolymer networks have been measured by thermoporometry using CCl4 as a probe liquid. All numerical relationships required for the calculation of the MSD were established for both the liquid-to-solid and the solid-to-solid thermal transitions of CCl4 and successfully validated on test samples. It was found that the polymer network, for both thermally and photo-cross linked materials, was completely built in about four hours of exposure. A clear correlation was established between the average mesh size of the swollen polymer network on the one hand and the benzoyl peroxide groups content and swelling ratio on the other hand

Polymeric materials temporality: application ime vs lifetime durability

International audienc

Cycle de vie des materiaux polymeres : de la durabilite a la temporalite

International audienc

Scientific aspects of the mechanical recycling of polymeric wastes

International audienc

Thermo-oxidation of polyterpenes: influence of the physical state

International audienc

Photooxidation of polyoctenamer: viscoelastic assessment of gel formation

International audienc

In situ detection of hindered amine stabilizer consumption in polymer through oxidation by indirect electron spin resonance

International audienc

Durabilité de composites bois – polymères biodégradables

Cette étude porte sur la photodurabilité de matériaux entièrement biodégradables : des composites bois – polymères biodégradables. Les matrices polymères sont le poly(acide lactique), l'Ecoflex$^\circledR$ et l'Ecovio$^\circledR$. Les charges sont différentes farines de peuplier dont certaines ont subi un traitement thermique appelé rétification, visant à diminuer leur hygroscopie et ainsi leur biodégradabilité. Ces mélanges (50/50) sont analysés par rhéométrie à l'état fondu et par analyse enthalpique différentielle (DSC) afin de caractériser leurs propriétés initiales. Ils sont ensuite soumis à un photovieillissement naturel et accéléré en enceinte et analysés de la même façon afin d'évaluer leur durabilité face à la lumière solaire. En effet, des mesures rhéologiques et thermiques vont nous permettre d'observer les changements intervenant au niveau moléculaire au cours de la dégradation et ainsi de proposer des mécanismes de photodégradation

Eco-Friendly Aliphatic Polyesters Containing 1,4-Cyclohexane Dicarboxylate Units: Effect of Diol Chain Length on Thermo-Mechanical Properties

Aliphatic polyesters containing 1,4-cyclohexylene rings are an interesting class of materials, not yet fully investigated. They potentially have the good characteristics typical of biopolyesters (for example, polyalkylene dicarboxylates and polyhydroxy alkanoates), such as sustainability and biodegradability. Indeed, renewable biomass resources can be used as feedstock to prepare the monomers and some preliminary tests of biodegradation suggest that the aliphatic rings do not hinder the microorganism attack.1 Moreover, the presence of cyclohexyl groups into the main chain provides rigidity to macromolecular chains, raises Tg, and imparts desirable physical-mechanical properties. In this way, the problem of the poor mechanical properties generally found in aliphatic polyesters can be solved. Finally, the 1,4-cyclohexylene unit shows the other remarkable peculiarity that it can have two possible configurations, cis and trans. In a polymer containing the 1,4-cyclohexylene rings, it will suffice to slightly modify the cis/trans isomeric ratio to obtain materials whose phase behavior changes from fully amorphous to semicrystalline.2 Therefore, the final properties of these materials can be easily tailored according to the specific applications. In this work diols with different chain length were tested as monomers for novel polyesters and the effects of the molecular characteristics on final properties were analyzed