Clément Lacoste

IMT Mines Alès | EMA · Centre for Materials Engineering (C2MA)

Different kinds of tannin-based foams were developed in the recent past with fisetinidin/robetinidin-type tannins extracted from mimosa (Acacia mearnsii) or quebracho (Schinopsis lorentzi) bark; or procyanidin-type tannins from pine (Pinus pinaster and Pinus radiata). These biobased porous products revealed excellent properties similar to their syn...

Mixed phenolic-polyurethane-type rigid foams were developed using tannin-furfuryl alcohol natural materials co-reacted with polymeric isocyanate in the proportions imposed by the limitations inherent to continuous industrial plants for polyurethane foams. A variety of different copolymerization oligomers formed. Urethanes appeared to have been form...

This study has the aim to propose a new simple method to determine the surface energy components of particles used as fillers in polymers. An experimental protocol coupled to a modified Jurin law is proposed. This protocol was applied to lignin particles used as reinforcement in polylactic acid (PLA). Some treatments were performed on lignin to imp...

The aim of this study was to investigate the structure–properties relationship of ternary blends of polylactide/polyhydroxybutyrate (PLA/PHB)/organo-modified layered silicate (OMLS). Morphological, thermal, rheological, and mechanical characterizations were performed to understand the influence of OMLS on PLA/PHB (70/30 wt%) formulations optimized...

The estimation of solid surface energy is generally obtained through the determination of liquid/solid contact angles. Many questions arise in the literature about the appropriate contact angle to use (dynamic, quasi-static or static, measured at a macro or a micro-scale). Theoretically, equilibrium contact angles should be inserted into equations...

In the present study, poly(3-hydroxybuturate-co-3-hydroxyvalerate) (PHBV) and plasticized polylactide acid (PLA) blends were processed by melt extrusion with different weight ratio (up to 20 wt.% of PHBV). Bionanocomposites were obtained through the incorporation of an organomodified montmorillonite (C30B) at 3 wt.%. The main features of the proces...

The aim of this work was an investigation of the ability of gallic (GA) and ellagic (EA) acids, which are phenolic compounds encountered in various plants, to act as flame retardants (FRs) for epoxy resins. In order to improve their fireproofing properties, GA and EA were treated with boric acid (to obtain gallic acid derivatives (GAD) and ellagic...

Wood-plastic composites were prepared by impregnating softwood and tropical hardwood by a radiation-curing resin containing phosphorus or chlorine groups as flame retardant. Microscopic observations revealed that the heterogeneous impregnation depends on the density but also on the wood species and sample orientation. Physical properties (hardness,...

Tannins are one of the most natural, non-toxic, and highly reactive aromatic biomolecules classified as polyphenols. The reactive phenolic compounds present in their chemical structure can be an alternative precursor for the preparation of several polymeric materials for applications in distinct industries: adhesives and coatings, leather tanning,...

In view of their use as source material for new bio-based flame retardants, chestnut wood extracts were prepared using different solvent systems and compared to an industrial extract. The prepared extracts were mainly composed of hydrolyzed products of ellagitannins (castalin, vescalin and ellagic acid) along with saccharides. The proportions of co...

The main objective of this study is devoted to the development of new insulating and ignifuged miscanthus fibers (Mf)/recycled textile fibers (RTf) reinforced biocomposites (BCs) using chitosan as polysaccharide‐based binder and aluminum trihydroxide (ATH) fillers while focusing on the fire behavior. To achieve this goal, a preliminary study was ca...

Alginate derived from seaweed is a natural polysaccharide able to form stable gel through carbohydrate functional groups largely used in the food and pharmaceutical industry. This article deals with the use of sodium alginate as an adhesive binder for wood fibres/textile waste fibres biocomposites. Several aldehyde-based crosslinking agents (glyoxa...

Matériau bio-composite, éco-conçu, destiné à de multiples applications dans les domaines du Bâtiment principalement et des Transports, constitué de renforts d'origine bio-sourcée exclusivement végétale, caractérisé par son mélange de fibres végétales très largement majoritaires entre 90% à 100% du composite, entre fibres brutes et sous-produits de...

Conventional foams derived from petroleum are extensively used for insulating uses. Research into alternative sources to petroleum based chemicals is attracting a great deal of attention. Softwood bark and in special, maritime pine bark from European forests is an abundant co-product from forest industries. In this study, the production of formalde...

Tannin-based foams were successfully prepared, using Norway spruce and maritime pine tannins. Various parameters, including the amount of procyanidins, were varied in order to observe the effect of changes in the density of the foam, on the structure its pores, and on the homogeneity, compressive strength, and compressive modulus of the foams. It w...

Neré (Parkia biglobosa) or African locust bean tree tannins have been extracted in two different ways: (i) by an artisanal maceration method and (ii) by a commercial-like extraction in presence of bisulfite. The type of oligomers obtained in the two cases were rather different. Mostly polyphenolic oligomers are present in the case of the commercial...

Les mousses rigides constituent une classe très importante de matériaux de par leur large champ d’applications et de leur poids économique considérable. Le développement de mousses à base de tannins a permis d’obtenir des matériaux issus à 90% de produits naturels. Dans ce travail, un type de tannins très réactif dit « procyanidine », a été employé...

Highly flexible films and strongly adhering surface finishes were prepared by reacting partially aminated polyflavonoid tannins with furfuryl alcohol in the presence of plasticisers such as glycerol or polyethylene imine. 13C NMR analysis showed partial amination of the tannin under the conditions used and even the formation of some N bridges betwe...

Pine bark tannin foams were prepared for the first time. The high reactivity of pine tannins in relation to other tannins induced the change in the tannin foam formulations in order to coordinate foam resin hardening, reaction exotherm and solvent blowing allowing the formation of a rigid foam. Pine tannin foams with and without formaldehyde were p...

Rigid foams based on tannin extracted form Pinus radiata bark have been recently developed and present many advantages for use as an insulation material instead of synthetic foams. Formaldehyde-free, in reality any-ldehyde-free pine tannin foams have been developed but present lower mechanical resistance undergoing compression. In this work, formal...

Tannin/furanic rigid foam made from raw materials of natural origin could be used to replace polyurethane and phenolic foams in many future applications. In this study, diethyl ether, pentane, and a mixture of the two were used to prepare tannin/furanic foams having different microstructures. It was found that the bulk density of the foam could be...