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Personne :
Blanchet, Pierre

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Blanchet

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Pierre

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Université Laval. Département des sciences du bois et de la forêt

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ncf11848384

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Voici les éléments 1 - 10 sur 27
  • PublicationAccès libre
    Impregnation of wood with microencapsulated bio-based phase change materials for high thermal mass engineered wood flooring
    (MDPI, 2018-12-19) Mathis, Damien; Landry, Véronic; Blanchet, Pierre; Lagière, Philippe
    Wood is a porous material that can be impregnated and have enhanced properties. Two species of hardwood, red oak (Quercus rubra L.) and sugar maple (Acer saccharum Marsh.), were impregnated in a reactor with a microencapsulated phase change material. The objective was to enhance the thermal mass of wood boards used as surface layers for engineered wood flooring manufacturing. Preliminary experiments were conducted on small samples in order to define suitable impregnation parameters, based on the Bethell cycle. Thin wood boards were impregnated with a microencapsulated phase change material dispersed into distilled water. Several cycles of pressure were applied. Heating storage of the impregnated wood boards was determined using a dynamic heat flow meter apparatus method. A latent heat storage of 7.6 J/g over 3 °C was measured for impregnated red oak samples. This corresponds to a heat storage enhancement of 77.0%. Sugar maple was found to be harder to impregnate and thus his thermal enhancement was lower. Impregnated samples were observed by reflective optical microscopy. Microcapsules were found mainly in the large vessels of red oak, forming aggregates. Pull-off tests were conducted on varnished samples to assess the influence of an impregnation on varnish adhesion and no significant influence was revealed. Engineered wood flooring manufactured with impregnated boards such as characterized in this study could store solar energy and thus improve buildings energy efficiency. Although wood is a material with a low-conductivity, the thermal exchange between the PCM and the building air could be good enough as the microcapsules are positioned in the surface layer. Furthermore, flooring is an area with frequent sunrays exposure. Such high thermal mass EWF could lead to energy savings and to an enhancement of occupant’s thermal comfort. This study aimed to characterize the potential of impregnation with MPCM of two wood species in order to make high thermal mass EWF.
  • PublicationRestreint
    Chemical surface densification of hardwood through lateral monomer impregnation and in situ electron beam polymerization, Part II : effect of irradiation dose on hardness, wood chemistry and polymer conversion
    (Springer Science, 2022-03-21) Triquet, Juliette; Landry, Véronic; Blanchet, Pierre
    Surface chemical densification was recently introduced as a low cost and fast process to improve surface hardness of wood. The asymmetric density profile at the surface due to polymer filled cells was achieved through unilateral impregnation of monomers and their fast in situ polymerization under electron beam radiations. This study investigates the effect of electron beam dose on the newly developed material in order to optimize and increase the performances. Effect of doses from 25 to 125 kGy on wood and polymer in situ were investigated by FTIR spectroscopy, confocal Raman microscopy and GC–MS quantification of extracted residual monomers. Brinell hardness of irradiated controls decreased with increased dose while it remained unchanged for densified samples. The effect of 25 kGy on the irradiated wood controls was insignificant, but evidence of cellulose depolymerization and decrease of hydrogen bonds strength was found at higher dose through FTIR analysis. Raman investigation of the acrylate conversion in situ showed that most of the polymerization was achieved with 25 kGy. Residual monomers were still present in the wood samples up to 100 kGy. Thus, 25 kGy was sufficient to polymerize monomers in situ and increase Brinell hardness of densified wood while avoiding degradation of wood. However, 100 kGy was necessary to ensure highest conversion and no residual monomers. This study is opening perspectives on radiation effects on wood for optimal materials development.
  • PublicationRestreint
    Chemical surface densification of hardwood through lateral monomer impregnation and in situ electron beam polymerization, Part I : density profile and surface hardness of three hardwood species
    (SpringerLink, 2021-03-23) Triquet, Juliette; Landry, Véronic; Blanchet, Pierre
    Filling wood cells with polymeric materials offers great opportunities to improve wood strength. Some applications, such as flooring, may require densification on one side of the material only. Yellow birch (Betula alleghaniensis Britt.), sugar maple (Acer saccharum Marsh.) and red oak (Quercus rubra L.) were surface densified through lateral chemical impregnation of monomers under vacuum followed by in situ electron beam polymerization. Lateral impregnation led to low mean chemical retention of 4% for sugar maple, 11% for red oak and 12% for yellow birch. X-ray densitometry and microtomography revealed an asymmetric density profile comparable to mechanically surface densified wood due to polymer-filled vessels. Scanning electron microscopy images showed presence of polymer-filled fibers beneath the surface. Brinell hardness of all species increased significantly compared to untreated wood. Low chemical retention significantly improved hardness due to localized polymer beneath the surface. Density profile characteristics were extracted from densitometry curves and correlated to hardness. Deep monomer penetration was more favorable to hardness than high surface density peak.
  • PublicationAccès libre
    Parametric study of a yellow birch surface impregnation process
    (Springer, 2021-03-29) Frias de Albuquerque, Mariana; Triquet, Juliette; Bégin-Drolet, André; Landry, Véronic; Blanchet, Pierre
    Wood is a renewable resource that has been used as a material in appearance products for years. Despite its acceptable mechanical resistance, different modification processes were developed to enhance wood’s hardness and make it an even more durable material. Impregnating wood pores with monomers under vacuum-pressure cycle is a common method for that purpose. However, most implemented processes are long and mostly submerge wood into a monomer formulation (Bethell’s full-cell process). For that, they can be considered wasteful on the quantity of materials used, energy consumed and on process duration. The objective of this paper was to evaluate the parameters that influence the penetration of monomers into the tangential surface of Yellow birch (Betula alleghaniensis Brit.) samples. The analyzed factors were the monomer formulation’s viscosity, the surface temperature, the vacuum level applied to the process, the anatomy of samples, and the absorption time. After impregnation, the weight gain of the samples was calculated. Monomer penetration depth was calculated and visualized using density profiles and micro X-ray tomography imaging. Results showed that using a low viscosity monomer formulation allied to a certain level of vacuum and absorption time can considerably increase the impregnation into the wood.
  • PublicationAccès libre
    Investigation of cellulose filaments as filler in rigid insulating polyurethane foam
    (Raleigh, N.C. : Department of Wood and Paper Science, College of Natural Resources, North Carolina State University, 2023-07-21) Beaufils-Marquet, Manon; Blanchet, Pierre; Hussain, Atif; Landry, Véronic
    Cellulose is a biopolymer that has broad potential applications including in building insulation, and it was studied for its potential as a filler material. A closed-cell polyurethane foam insulation formulation was developed, and cellulose filaments (CFs) were introduced at varying percentages. The viscosity and morphology of the formulations were studied, as were different foam properties, such as water vapor permeability, reaction kinetics, density, porosity, thermal conductivity, and compressive strength foams as a function of cellulose filaments content. A commercial foam was also tested as a reference. The cellulose filaments impacted the formulations’ viscosity, and all the properties of the resulting insulating material. For example, samples containing 5% of cellulose filaments were found to perform differently than samples containing 0%, 1% and 2.5% mainly due to agglomerate formation, which impacted cell size (about 0.1 mm2 at 0%, 1% and 2.5% versus a mean of over 0.4 mm2 at 5%), and differential vapor sorption (with a mass change of 2%wt at 0 parts per hundred of polyol versus 2.5%wt at 5% from 0% to 95% relative humidity). However, the required performances by the standards of polyurethane foam insulation material were always fulfilled regardless of the amount of cellulose filaments present.
  • PublicationAccès libre
    Preparation and characterisation of flame retardant encapsulated with functionalised silica-based shell
    (Taylor & Francis, 2018-09-07) Dagenais, Christian; Schorr, Diane; Hoang, Doan-Trang; Vanslambrouck, Stéphanie; Landry, Véronic; Blanchet, Pierre
    Intumescent fire retardant (IFR) coatings are nowadays considered as the most effective flame retardant (FR) treatment. Nevertheless, the principal compound in an IFR system, ammonium polyphosphate (APP), is highly sensitive to moisture and IFR coating effectiveness decreases quickly. The main objective of this study is to encapsulate APP in a hybrid silica-based membrane by sol-gel process using alkoxysilane tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) precursor. The morphology and structure of APP and microencapsulated ammonium polyphosphate (MAPP) were assessed by scanning electron miscroscopy and Fourier transform infrared spectroscopy (FTIR). X-ray photoelectron spectroscopy (XPS) results revealed that APP was well encapsulated inside the polysiloxane shells. The thermal degradation of APP and MAPP was evaluated by thermogravimetric analysis. At 800°C, the MAPP had higher char residue (70.49 wt%) than APP (3.06 wt%). The hydrophobicity of MAPP increased significantly with the water contact angles up to 98°, in comparison to 20° for APP.
  • PublicationAccès libre
    Interactions between a buffered amine oxide impregnation carrier and an acrylic resin, and their relationship with moisture
    (MDPI, 2020-04-07) Pepin, Simon; Landry, Véronic; Blanchet, Pierre
    Wood used outdoor is subjected to different sources of degradation and should be protected properly. In this study, acrylic resins were added to a wood impregnation system using amine oxides and propiconazole, an organic fungicide, to create a two-part wood protection preservation treatment. Since amine oxides can diffuse readily into wood, this treatment protected both the surface and inner structure of the treated wood following a simple dipping. Many aspects of the treatment were studied: the adhesion of the acrylic coatings, their permeability to water, and the impregnation depth of the propiconazole. In each case, a particular attention was accorded to the interactions between the resins and the impregnation system. Adhesion and permeability tests were coupled with an artificial aging process simulating severely wet conditions. Amine oxides reduced the adhesion of the coatings but did not impair their aging properties. Because of their hydrophilic nature, they also increased the permeability to liquid water, although they did not affect the air moisture permeability. The penetration of the propiconazole, estimated with a dye, decreased with the resin. Overall, the two parts of the treatment lightly impaired each other, but the practical aspect of this treatment may overcome these disadvantages.
  • PublicationAccès libre
    Characterization of the diffusion of organic fungicides with amine oxides in white pine and white spruce
    (Dept. of Wood and Paper Science, College of Natural Resources, North Carolina State University, 2019-12-18) Pépin, Simon; Landry, Véronic; Blanchet, Pierre
    Wood products, especially those used in outdoor conditions, can be damaged by dimensional changes and decay fungi. It is therefore advised to use impregnation treatments to mitigate these hazards. While the potency of the chemicals employed in the treatments is important, characterization of the treatments is also crucial to ensure deep and durable protection. In this study, eastern white pine (Pinus strobus L.) and white spruce (Picea glauca (Moench) Voss) were impregnated with propiconazole and 3-iodo-2-propynyl butylcarbamate (IPBC) through diffusion. Instead of using pressure treatments, the samples were dipped in solutions containing amine oxides, which can diffuse into the wood. The treatments were characterized by the mass of fungicide impregnated, fungicide leaching, and the impregnation depths of both the fungicides and the amine oxides. It was found that the treatment impregnated slightly more than 0.040 kg/m3 of both fungicides, meeting EU standards. It was also shown that the presence of amine oxides slightly prevented the leaching of the fungicides in white pine. The penetration of the amine oxides was several millimeters deep in all directions, but the penetrations of the fungicides were much shorter and only longitudinal.
  • PublicationAccès libre
    Hardness of chemically densified Yellow birch in relation to wood density, polymer content and polymer properties
    (de Gruyter, 2020-08-24) Triquet, Juliette; Landry, Véronic; Blanchet, Pierre
    Density of wood can be increased by filling its porous structure with polymers. Such densification processes aim to increase hardness of wood and are particularly interesting for flooring applications. This study aims to evaluate efficiency of different polymers for chemical densification based on the polymer properties. Yellow birch (Betula alleghaniensis Britt.) was chemically densified with seven monomer mixtures through acrylate monomer impregnation and electron beam in-situ polymerization. Chemical retention and polymer content of densified woods were recorded. Hardness of treated and untreated Yellow birch was measured and compared to hardness of Jatoba (Hymenaea courbaril L.). All densified woods showed higher or comparable hardness to Jatoba. Hardness of densified wood was analyzed in relation to initial density of wood and polymer content of the material using multivariable linear mixed models. Efficiency of polymers for chemical densification was evaluated through effect of polymer content on hardness with interaction coefficients. Polymer films corresponding to monomer impregnating mixtures were prepared through low energy electron beam and characterized by their glass transition temperature, micro hardness, indentation modulus and crosslinking density. Polymers showed statistically significantly different efficiencies and were separated in two main groups. Overall, polymer efficiency increased with increasing glass transition temperature of polyacrylates.
  • PublicationAccès libre
    Thermal characterization of bio-based phase changing materials in decorative wood-based panels for thermal energy storage
    (Institute of Process Engineering, Chinese Academy of Sciences, 2018-06-08) Mathis, Damien; Landry, Véronic; Blanchet, Pierre; Lagière, Philippe
    Decorative wood panels containing pouches of bio-based phase changing materials (PCMs) were prepared. Three different PCM mixtures were used: a blend of capric and lauric acids as well as two commercial products, Puretemp®20 and Puretemp®23 (Puretemp). The panels consist of engraved Medium Density Fiberboard (MDF) filled with a plastic pouch filled with PCM. High density fiberboard (HDF) was used on top of the panels to enclose the PCM pouches. PCM mixtures were first tested by differential scanning calorimetry (DSC). Phase change temperature and total heat storage of the panels were measured for both fusion and solidification with a Dynamic Heat-Flow Meter Apparatus (DHFMA). DSC and DHFMA results were compared, allowing a better understanding of results gathered from these two techniques. DSC calibration has been revealed important when assessing PCMs. The panels present a phase change temperature and a latent heat storage suitable for buildings applications. The panel made with Puretemp®23 presented the highest energy, with 57.1 J/g. Thermal cycling was conducted on the panels to investigate thermal reliability, which revealed small modifications of thermal properties for two products. For all cases, latent heat was found stable. Hygro-mechanical behavior of the panels was also evaluated as these where designed to be aesthetic decorative panels. This study exposes the potential of a new type of wood-based panels loaded with PCM for thermal energy storage and brings overall knowledge about PCM products thermal characterization.