Laurent Matuana - Academia.edu (original) (raw)

Papers by Laurent Matuana

Journal of Applied Polymer Science, 2006

This study examined the durability of extruded HDPE/wood‐flour composites exposed to 15 accelerat... more This study examined the durability of extruded HDPE/wood‐flour composites exposed to 15 accelerated cycles of water submersion, freezing, and thawing, according to ASTM standard D6662. The durability of both maple and pine composites was assessed by testing the flexural properties and density. Mercury intrusion porosimetry and scanning electron microscopy were also used to evaluate the interfacial adhesion between the matrix and wood flour before and after exposure to accelerated freeze–thaw cycling. Freeze–thaw actions had no apparent effect on the density of the composites after exposure, regardless of the wood species. However, these actions led to moisture uptake, which decreased the interfacial adhesion and increased the pore size and quantity in the composites, which resulted in a significant loss in flexural properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 100: 35–39, 2006

Journal of Applied Polymer Science, Jul 10, 2020

Utilization of orange peel (OP) from the juicing industry as filler material within a polymer mat... more Utilization of orange peel (OP) from the juicing industry as filler material within a polymer matrix can add value to this agricultural waste and reduce dependence on nonrenewable resources. This study aims to investigate the impact of OP filler's physical characteristics including size, loading, and retention/removal of zest on plastic properties of interest for food packaging. Linear low-density polyethylene (LLDPE) is selected to produce plastic composites due to its widespread use in food packaging. Eight different LLDPE/OP sheets from combinations of different OP characteristics are examined. Results show that OP particle sizes of 75-177 μm without zest at 0.4-g loading improve thermal stability, color, dispersion, tensile strength, modulus of elasticity, and elongation at break as well as reduce air bubble formation and OP agglomerate sizes in LLDPE/OP composites. Results show a promise in utilization of OP fillers to produce a composite comparable to neat LLDPE and composites with UV-blocking properties.

Journal of Applied Polymer Science, 2004

ABSTRACT The effect of high-density polyethylene (HDPE)/polypropylene (PP) blending on the crysta... more ABSTRACT The effect of high-density polyethylene (HDPE)/polypropylene (PP) blending on the crystallinity as a function of the HDPE melt index was studied. The melting temperature and total amount of crystallinity in the HDPE/PP blends were lower than those of the pure polymers, regardless of the blend composition and melt index. The effects of the melt index, blending, and foaming conditions (foaming temperature and foaming time) on the void fractions of HDPEs of various melt indices and HDPE/PP blends were also investigated. The void fraction was strongly dependent on the foaming time, foaming temperature, and blend composition as well as the melt index of HDPE. The void fraction of the foamed 30:70 HDPE/PP blend was always higher than that of the foamed 50:50 HDPE/PP blend, regardless of the melt index. The microcellular structure could be greatly improved with a suitable ratio of HDPE to PP and with foaming above the melting temperature for long enough; however, using high-melt-index HDPE in the HDPE/PP blends had a deleterious effect on both the void fraction and cell morphology of the blends. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 364–371, 2004

Journal of Applied Polymer Science, Sep 29, 2003

Wood-plastic composites are being increasingly examined for nonstructural or semistructural build... more Wood-plastic composites are being increasingly examined for nonstructural or semistructural building applications. As outdoor applications become more widespread, durability becomes an issue. Ultraviolet exposure can lead to photodegradation, which results in a change in appearance and/or mechanical properties. Photodegradation can be slowed through the addition of photostabilizers. In this study, we examined the performance of wood flour/ high-density polyethylene composites after accelerated weathering. Two 2 4 factorial experimental designs were used to determine the effects of two hindered amine light stabilizers, an ultraviolet absorber, a colorant, and their interactions on the photostabilization of high-density polyethylene blends and wood flour/high-density polyethylene composites. Color change and flexural properties were determined after 250, 500, 1000, and 2000 h of accelerated weathering. The results indicate that both the colorant and ultraviolet absorber were more effective photostabilizers for wood flour/high-density polyethylene composites than the hindered amine light stabilizers.

Current research in green and sustainable chemistry, 2023

Cellulose nanocrystals (CNCs) are routinely produced as aqueous suspensions. These are then typic... more Cellulose nanocrystals (CNCs) are routinely produced as aqueous suspensions. These are then typically freeze-dried in order to be added into polymeric composites using melt-blending. However, dispersing freeze-dried CNCs into hydrophobic polymers is a challenge. In this study, our objective was to advance our understanding of the impact of freeze-drying methods on the morphology of dried cellulose nanocrystals (CNCs), and on the tensile properties of the resulting PLA-CNC nanocomposites. CNCs were prepared as aqueous suspensions with 10.7% solids content using a sulfuric acid method, and freeze-dried using a procedure typical to our laboratory. In addition, the CNC aqueous suspension was diluted to 1% and directly freeze-dried or sonicated for 10 or 30 minutes, flash frozen, and freeze-dried. The particle size and morphology of the CNCs before and after freeze drying were determined by microscopy. CNCs were then incorporated into PLA using melt-blending extrusion and injection molding. The PLA-CNC nanocomposites were tested for thermal and mechanical properties. Before freeze-drying, CNCs were nano-scale, while agglomerations were observed after freeze-drying. The agglomerate sizes were reduced with dilution and/or increased sonication time, with fibrillar structures observable after sonication and flash freezing. PLA-CNC composites containing CNCs that were subjected to dilution, sonication for 30 minutes, flash frozen and freeze-dried had higher tensile modulus and strength compared with the other treatments.

Forest Products Journal, 2003

In conventional approaches to reducing the press time of wood composites, high press temperatures... more In conventional approaches to reducing the press time of wood composites, high press temperatures and/or an external catalyst is often used to accelerate the resin cure rate to obtain acceptable press times. This paper explored the concept of combining a thermally conductive carbon filler material (e.g., synthetic graphite) with wood particles and flakes as a means to promote resin cure. The experimental results indicate that synthetic graphite does not act as a catalyst. Rather, graphite allows a faster resin cure by accelerating the heat (higher temperatures) into wood composites due to its higher thermal conductivity (600 Wm -1 K -1 ) as compared to the low thermal conductivity of the wood (0.2 Wm -1 K -1 ).

Journal of Food Engineering, Mar 1, 2023

Journal of the Korean wood science and technology, 2006

ABSTRACT Value-added utilization of the disposed ash trees due to the infestation by Emerald Ash ... more ABSTRACT Value-added utilization of the disposed ash trees due to the infestation by Emerald Ash Borer (EAB) was explored by converting them into particleboards (PBs) and wood-plastic composites (WPCs). The experimental result showed that PB panels could be successfully manufactured from the ash wood but compaction ratio need to be higher than 1.3 in order to meet the standard requirements listed by American National Standards Institute (ANSI). Ash wood plastic composites with high density polyethylene (HDPE) and polypropylene (PP) were also prepared with additives by extrusion. Physical and mechanical properties of ash wood plastic composite compared favorably to those made of pine and maple.

Value-added utilization of ash trees infested by emerald ash borers (EABs) was explored by conver... more Value-added utilization of ash trees infested by emerald ash borers (EABs) was explored by converting ash chips into particleboard (PB) panels and wood-plastic composites (WPCs). Experimental results showed that PBs and WPCs could be successfully manufactured from ash trees, including those infested by EABs. Mechanical properties of PB met or exceeded the current standard requirements listed by the American National Standards Institute. The properties of ash-based WPCs compared favorably to WPCs made with pine and maple flours.

International Journal of Polymeric Materials, Nov 1, 2004

The effects of wood fiber content on the void fraction, cell morphology, and notched Izod impact ... more The effects of wood fiber content on the void fraction, cell morphology, and notched Izod impact strength of microcellular foamed HDPE/PP blend composites with wood fiber were studied. The influence of wood fiber content on the carbon dioxide adsorption and desorption in the samples was also examined. Adsorption of carbon dioxide decreased with increased wood fiber content. Gas diffusion rates

Journal of Vinyl & Additive Technology, Oct 22, 2013

The effect of light stabilizer's addition method into wood-plastic composites (WPCs), i.e., surfa... more The effect of light stabilizer's addition method into wood-plastic composites (WPCs), i.e., surface versus bulk, on their photostability was evaluated. Blends of ultraviolet absorbers (benzotriazole or hydroxyphenyltriazine) with a hindered amine light stabilizer were used as the stabilizing additives. Both unstabilized and photostabilized uncapped (control) samples, as well as coextruded WPCs counterparts, were exposed to up to 3000 h of accelerated artificial weathering. The light transmittance, surface morphology, and color of the samples before and after weathering were analyzed by UV-vis spectroscopy, SEM, and Chroma Meter. The experimental results indicated that the method of adding the light stabilizer had a significant effect on the WPC photostability. While bulk addition reduced the degree of fading in uncapped composite, it did not suppress it completely. On the other hand, coextruded WPCs with photostabilized cap layers showed no visible signs of fading, thus clearly indicating that the stabilized cap layers blocked most of the UV radiation, and thereby prevent of UV light to reach the surface of the inner layer of coextruded composites. Costanalysis considerations indicated that 50 times more light stabilizer was needed when it was incorporated into the bulk of the composites rather than in the cap layer of coextruded samples. Clearly, these results suggest that adding light stabilizers at the surface of WPCs not only protects them against UV degradation, but also is a most efficient and cost-effective method of photostabilization than bulk addition. J. VINYL ADDIT.

Bioresources, Mar 24, 2015

In this study, banana petiole-based cellulose nanofibril (CNF) films treated with graphene oxide ... more In this study, banana petiole-based cellulose nanofibril (CNF) films treated with graphene oxide (GO) were prepared and evaluated by means of Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). Tensile strengths (TS), dynamic mechanical properties, and thermal stabilities of the films were affected positively when the GO loading was less than 4.4 wt%. From these results, FTIR spectra, and SEM analyses, a strong coupling between the GO and the cellulose matrix could be concluded at lower GO loadings. The TGA and DMA results also suggested that the CNF film treated with 4.4 wt% GO had more char residue, better thermal stability, higher storage modulus, and higher retention ratio when compared to that without treatment. This work provides a new approach for more effective utilization of banana petiole as a feedstock for CNF and GO/CNF composites.

Polymer International, 2009

Wood/plastic composites (WPCs) can absorb moisture in a humid environment due to the hydrophilic ... more Wood/plastic composites (WPCs) can absorb moisture in a humid environment due to the hydrophilic nature of the wood in the composites, making products susceptible to microbial growth and loss of mechanical properties. Co-extruding a poly(vinyl chloride) (PVC)-rich cap layer on a WPC significantly reduces the moisture uptake rate, increases the flexural strength but, most importantly, decreases the flexural modulus compared to uncapped WPCs. A two-level factorial design was used to develop regression models evaluating the statistical effects of material compositions and a processing condition on the flexural properties of co-extruded rigid PVC/wood flour composites with the ultimate goal of producing co-extruded composites with better flexural properties than uncapped WPCs. Material composition variables included wood flour content in the core layer and carbon nanotube (CNT) content in the cap layer of the co-extruded composites, with the processing temperature profile for the core layer as the only processing condition variable. Fusion tests were carried out to understand the effects of the material compositions and processing condition on the flexural properties. Regression models indicated all main effects and two powerful interaction effects (processing temperature/wood flour content and wood flour content/CNT content interactions) as statistically significant. Factors leading to a fast fusion of the PVC/wood flour composites in the core layer, i.e. low wood flour content and high processing temperature, were effective material composition and processing condition parameters for improving the flexural properties of co-extruded composites. Reinforcing the cap layer with CNTs also produced a significant improvement in the flexural properties of the co-extruded composites, insensitive to the core layer composition and the processing temperature condition.

Food and Bioprocess Technology, Feb 8, 2019

The goal of this study was to produce a film made of egg white protein (EWP) through extrusion an... more The goal of this study was to produce a film made of egg white protein (EWP) through extrusion and calendering processes, the most common filmmaking processing technology, and to determine its potential for food packaging applications. The latter was assessed by measuring the mechanical, barrier, thermal, and optical properties; plasticizer leakage; and microbial resistance of the EWP film when exposed to specific combinations of relative humidity (RH) and temperature, and by comparing some of the results to those of commercial polylactic acid (PLA) film, the most commonly used bioplastic for food packaging applications. A transparent, continuous, thin, and uniform EWP film was produced with extruder-zone temperatures of 40°C-50°C-60°C-70°C-75°C from feeder to die and with roller temperatures and speed set to 115-120°C and 0.111 rpm. The permeability, lightness, and transmittance of the resulting film were affected by temperature while the RH affected its thickness, tensile properties, permeability, color, transmittance, and glycerol loss. Compared to the PLA film, the EWP film was less breakable and flexible, and had a lower barrier to water and higher rigidity, thermal resistance, and barrier to oxygen. The two materials present similar transparency, lightness, color, barrier to ethanol, and sensitivity to RH. This study proves that EWP film can be produced through extrusion and calendaring processes and can be used as an alternative to other materials for food packaging applications where thermal resistance, rigidity, strength, barrier to oxygen, and avoidance of condensation are desired.

Journal of Vinyl & Additive Technology, Dec 1, 2008

Wood-plastic composites (WPCs) can absorb moisture in a humid environment owing to the hydrophili... more Wood-plastic composites (WPCs) can absorb moisture in a humid environment owing to the hydrophilic nature of the wood, thereby making the products susceptible to microbial growth and loss of mechanical properties. In this study, rigid poly(vinyl chloride) (PVC)/wood-flour composites (core layer) were coextruded with either unfilled rigid PVC (cap layer) or rigid PVC filled with a small amount (5-27.5%) of wood flour (composite cap layers) in order to decrease or delay the moisture uptake. The thickness of the cap layer and its composition in terms of wood flour content were the variables examined during coextrusion. Surface color, moisture absorption, and flexural properties of both coextruded and noncoextruded (control) composite samples were characterized. The experimental results indicated that both unfilled PVC and composite cap layers can be encapsulated over rigid PVC/wood-flour composites in a coextrusion process. The moisture uptake rate was lower when a cap layer was applied in the composites, and the extent of the decrease was a strong function of the amount of wood flour in the cap layer but insensitive to cap layer thickness. Overall, coextruding PVC surface-rich cap layers on WPCs significantly increased the flexural strength but decreased the flexural modulus as compared with those of control samples. The changes in bending properties were sensitive to both cap layer thickness and wood flour content.

Polymer Degradation and Stability, 2011

This study examined the effect coextruding a clear HDPE cap layer onto HDPE/wood-flour composites... more This study examined the effect coextruding a clear HDPE cap layer onto HDPE/wood-flour composites has on the discoloration of coextruded composites exposed to accelerated UV tests. Chroma meter, FTIR-ATR, XPS, SEM, and UV vis measurements accounted for the analysis of discoloration, functional groups, and degree of oxidation of both uncapped (control) and coextruded composites before and after UV exposures. Two separate discoloration characteristics occurred in the discoloration of composites. For uncapped WPCs (control), chemical changes due to photooxidation resulted in darkening followed by physical changes, including loss of colored wood components from the surface, as well as increased roughness on the surface, which led to lightening of WPCs. By contrast, because a hydrophobic cap layer prevented the loss of colored components from the surface, coextruding a clear hydrophobic HDPE cap layer over WPCs significantly decreased the discoloration during the weathering process. Photooxidation of wood components at the interface accounted for the discoloration of coextruded WPCs before the failure of cap layer. Moreover, as the cap layer absorbed a specified amount of UV light and reduced oxygen available to interface, it decreased the photooxidation rate at the interface compared to that at the WPCs surface.

Bioresource Technology, Jun 1, 2008

Poly(lactic acid) or PLA is a plant-based biodegrable plastic which exhibits many properties that... more Poly(lactic acid) or PLA is a plant-based biodegrable plastic which exhibits many properties that are equivalent to or better than many petroleum-based plastics. However, there have been few commercial applications due to its lower impact resistance and higher cost than synthetic plastics. In this paper, the concept of creating microcellular foamed structures in PLA as a means to improve its shortcomings is presented. The effect of the foaming conditions (temperature and time) on the void fraction, volume expansion ratio, impact strength and tensile properties of foamed PLA is discussed. Each step of microcellular processing is addressed including: the manufacture of PLA film; the saturation of the samples with gas; the microcellular foaming of PLA; the void fraction determination, volume expansion ratio calculation, impact and tensile property characterization of foamed samples. The microcellular morphologies developed in PLA samples were a strong function of the foaming conditions. Due to the presence of foamed microcells, a twofold expansion ratio and significant improvements in the impact resistance (twofold increase over unfoamed PLA), strain at break (up to twofold increase over unfoamed PLA) and toughness (up to fourfold increase over unfoamed PLA) were achieved in PLA.

Journal of Applied Polymer Science, Jun 20, 2003

In this study, the effects of batch processing conditions (foaming time and temperature) and blen... more In this study, the effects of batch processing conditions (foaming time and temperature) and blend composition as well as the effect of incorporating wood fiber into the blends on the crystallinity, sorption behavior of CO2, void fraction, and cellular morphology of microcellular foamed high‐density polyethylene (HDPE)/polypropylene (PP) blends and their composites with wood fiber were studied. Blending decreased the crystallinity of HDPE and PP and facilitated microcellular foam production in blend materials. The void fraction was strongly dependent on the processing conditions and on blend composition. Foamed samples with a high void fraction were not always microcellular. The addition of wood fiber inhibited microcellular foaming. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2842–2850, 2003