Progress 02/01/06 to 01/31/11
Outputs
OUTPUTS: The initial focus of this project was on cellulosic nanocomposites that could be used in a variety of applications such as biomedical. Cellulose was combined with various polymers (polyethylene oxide and fibrin) in order to tailor their mechanical properties. Adding and co-reacting cellulose nanocrystals with thermosetting adhesives to determine their mechanical potential in these higher modulus polymers was investigated. Methods of characterization were pursued with work on the crystallization kinetics in cellulosic nanocomposites as this was one of the project's main objectives. Modification methods for lignocellulosic particles were explored using plasma polymerization as a green and cost-effective way to tailor the surface chemistry and improve the compatibility of these particles in many matrices. New knowledge was generated to develop cellulose based composites and to engineer the interphase chemistry in such composites. In particular, a new manufacturing approach for cellulose nanocomposites that integrates bioengineering and design of phase morphology was demonstrated. Atomic force microscopy and dynamic mechanical analysis protocols were developed to characterize the nanocomposites. Additionally, two analyses were conducted to understand the structure and morphology in lignocellusic composites: solid-state NMR and viscoelastic modeling of relaxation in wood/phenolic composites and the modeling of phenolic cure kinetics. Further studies involved with the modeling of molecular motions in bio-based composites found that the fiber orientation affected segmental relaxation of wood amorphous polymers suggesting a mechanical and/or constraining effect of the fibers. Research was also conducted on the surface modification of wheat straw for compatibilization with aminoplastic resins in the framework of medium density fiberboard (MDF) composites. Various surface modifications were attempted to improve adhesion of wheat straw with aminoplastic resins. MDF composites from wheat straw were manufactured with aminoplastic resins and mechanical properties above specifications for interior applications of MDF were observed. The applicability of a cooperativity analysis to evaluate interphases in composites was demonstrated and has allowed for some insight on the molecular weight effect of phenolic resins on the wood adhesive interphase. The nature of interactions between lubricants, coupling agents, thermoplastic and wood that are commonly used for wood plastic composites was investigated with solid state NMR. Finally, an atmospheric pressure cold plasma (APCP) polymerization process was developed that can alter the surface chemistry of the substrate to make the nanofibers more compatible with commodity thermoplastic resins, such as high density polyethylene and polypropylene, to name a few. PARTICIPANTS: In 2010 Dr. Karl Englund, project coordinator and graduate student supervisor/advisor, and Mr. William Lekobou, PhD student in Materials Science Program, conducted research focused on modifying the plasma and polymerization process for nanoparticle surface treatment. Dr. Marie-Pierre Laborie (PI) directly oversaw the project from 2003 to 2009. During this time she directly advised graduate and undergraduate students and the postdoc participating in the project. Dr. Hongzhi Liu, Post-Doctoral Research Associate at WSU, worked primarily on the preparation of cellulose nanoparticles and on the preparation and characterization of cellulosic thermosetting adhesives. Stephanie Pitts, senior in mechanical engineering, assisted with the preparation of cellulose nanoparticles. Over the lifetime of the project, others that worked on this project included several students and postgraduates who have been trained in this project including: Elvie Brown, who graduated with an MS in Chemical Engineering from WSU and who worked on cellulose nanocomposites for biomedical applications; Erica Rude, who graduated with an MS in Mechanical and Materials Engineering from WSU; Yu Geng, who was a post-doctoral fellow working on this project at WSU; Jinwu Wang, who graduated with PhD in Civil and Environmental Engineering at WSU; and Cao Qi, who graduated with an MS in Civil and Environmental Engineering at WSU. TARGET AUDIENCES: The forest products industry and especially pulp and paper and wood flour manufacturers will be one of the direct beneficiaries of our investigations since through our material development activities we will provide new market opportunities for cellulose and lignocellulosics. Composite manufacturers are also a target audience for this process and final product. The findings on bacterial cellulose nanowhisker and fibrin composites may also attract interest from the biomedical industry. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
This research provided new avenues for researchers to evaluate complex nanocomposite materials. Utilization of CP/MAS NMR for deciphering nanometer scale interactions in composites was demonstrated. The methods are important to gain better insight on the morphology and ultrastructure of natural lignocellulosic materials. As a result, properties and performance of the cellulosic nanocomposites can be tailored. The work on wood/thermosetting systems resulted in new methods to evaluate interactions at the interphase, which contributes to the design of wood/adhesive interphases for improved adhesion. The work on wood plastic composites will help develop novel formulations of polymer/coupling agents/ lubricants for improved interactions and performance.We demonstrated that cellulose nanocrystals are efficient reinforcements in thermosetting adhesives such as phenolic resins. We were able to co-react these nanocrystals with phenolic prepolymers, resulting in finely dispersed nanocomposites, and we demonstrated a significant increase in mechanical and thermal properties. This finding has significant applications, since such nano-reinforced adhesives could be used to lower the weight while increasing the performance of composites in various applications (transportation, construction, etc). Our current results in cellulose and thermoplastic nanocomposites (fibrin) show that we can manipulate to some extent the elasticity of the material for implant purposes. Finally our work on crystallization in nanocomposites provided valuable fundamental knowledge on the physics of those materials and how it might affect the flow and solidification properties of polymer matrices.
Publications
- No publications were submitted during 2010; much of the work on the refinement of our plasma process is complete and papers will be submitted in 2011. Over the lifetime of the project, 21 publications were produced.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: For the past year, we have worked on the development of nanocomposites using renewable cellulosic resources. In particular we have focused on cellulosic nanocomposites that could be used as biomedical devices such as blood vessel implants. Our work has consisted of combining cellulose with various polymers such as polyethylene oxide and fibrin in order to tailor their mechanical properties. The goal is to match the mechanical performance of the tissue these implants would replace. This work is in progress and we will assess the potential of various crosslinking chemistries to tailor performance. We have also worked on adding and co-reacting cellulose nanocrystals with thermosetting adhesives to determine their mechanical potential in these higher modulus polymers. At the same time we continue investigating methods of characterization, especially with recent work on the crystallization kinetics in cellulosic nanocomposites. Our current work now also focuses on modification methods for lignocellulosic particles using plasma polymerization as a green and cost-effective way to tailor the surface chemistry and compatibility of these particles in any matrices. One oral presentation was given on this work at the 62nd Gaseous Electronics Conf., while two other papers were accepted for oral presentation at the upcoming American Chemical Society Meeting. PARTICIPANTS: Dr. Marie-Pierre Laborie (PI), oversees the project, directly advises graduate and undergraduate students and the postdoc participating in the project. Dr. Hongzhi Liu, works primarily on the preparation of cellulose nanoparticles and on the preparation and characterization of cellulosic thermosetting adhesives. Stephanie Pitts, senior in mechanical engineering, assisted with the preparation of cellulose nanoparticles. Elvie Brown, PhD student in chemical engineering, is working on cellulose nanocomposites for biomedical applications. William Lekobou, PhD student in Washington State University's materials science program, is mainly involved in the modification of lignocellulosic particles with plasma polymerization. Drs. Jinwen Zhang and Karl Englund have been brought on to enhance the project team for the coming year. TARGET AUDIENCES: The forest products industry and especially pulp and paper companies will be the direct beneficiary of our investigations since we will provide new market opportunities for cellulose and lignocellulosics through our material development activities. The general public will also benefit from this work because it provides green alternatives to otherwise environmentally adverse materials thereby allowing our society to be less wasteful and polluting. For example, lighter and stronger materials in the transportation field would result in fuel economy and less emissions. Health benefits will also arise from the development of cellulose based implants. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We have demonstrated that cellulose nanocrystals could be very efficient reinforcements in thermosetting adhesives such as phenolic resins. We were able to co-react these nanocrystals with phenolic prepolymers, resulting in finely dispersed nanocomposites, and we demonstrated a very significant increase in various performance attributes including mechanical and thermal properties. This finding has significant applications, since such nano-reinforced adhesives could be used to lower the weight while increasing the performance of composites in various applications (transportation, construction, etc). Our current results in cellulose and thermoplastic nanocomposites (fibrin) show that we can manipulate to some extent the elasticity of the material for implant purposes. This finding is promising and we continue to fine tune our ability to tailor performance. Finally our work on crystallization in nanocomposites results in significant new fundamental knowledge on the physics of those materials and how it might affect the flow and solidification properties of polymer matrices. Although fundamental, this knowledge will have significant impact for understanding how to efficiently handle these materials in melt-processes.
Publications
- A. P. Mathew, M.-P. Laborie and K.Oksman. 2009. Cross-linked chitosan -chitin whiskers nanocomposites with improved permeation selectivity and pH stability, Biomacromolecules , 10(6), 1627-1632.
- M.-P. Laborie. 2009. Chapter 9. Bacterial Cellulose and its Polymeric Nanocomposites, in the Nanoscience and Technology of Renewable Biomaterials, Edited by L. Lucia and O. Rojas, Blackwell Publishing.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Mentoring of one graduate student and one post-doctoral research associate. Participation in conferences and proceedings: M.-P. Laborie and E. Brown. 2008. Bacterial cellulose/Polyvinyl alcohol nanocomposites, 234rd National Meeting of the American Chemical Society, New Orleans, LA, April 4-10. Submission of a book chapter for Biomass Nanotechnology: M.-P. Laborie 2008. Bacterial Cellulose and its Polymeric Nanocomposites, edited by L. Lucia and O. Rojas, Blackwell Publishing. PARTICIPANTS: Elvie Brown (Ph.D. candidate); Hongzhi Liu (Post-Doctoral Research Associate). TARGET AUDIENCES: The novel characterization tools for wood products can be useful to the forest products industry. Various industrial sectors (transportation and building) that use bio-based materials can benefit from the development of novel lignocellulosic nanocomposites. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Novel knowledge has been developed to understand the molecular basis of performance in lignocellulosic composites using 13C CP/MAS NMR spectroscopy. The novel tools have then been used to develop novel bioproduction methods of cellulosic nanocomposites. With this new bioproduction route, the chemical and morphological characteristics of the nanocomposites could be manipulated. As a result properties and performance of the cellulosic nanocomposites can be tailored.
Publications
- Rude, E.F., and M.P.Laborie. 2008. 13C CP/MAS NMR investigation of the interactions between maleic anhydride grafted polypropylene and wood polymers. Applied Spectroscopy. 62(5):562-568.
- Brown, E., and M.P.Laborie. 2008. Method of in situ bioproduction and composition of bacterial cellulose nanocomposites. US patent No 60/957,279.
- Brown, E., and M.P.Laborie. 2008. Bioengineering Bacterial Cellulose/Poly(ethylene oxide) Nanocomposites. Biomacromolecules. 9(12):3427-3428.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: New knowledge has been generated to develop cellulose based composites and to engineer the interphase chemistry in such composites. In particular a new manufacturing approach for cellulose nanocomposites that integrates bioengineering and design of phase morphology has been demonstrated. This knowledge has been widely communicated via national and international conferences and seminars including at the Micro Nano Breakthrough in Portland OR, the 28th Riso International Symposium on Materials Science in Denmark, the 233rd National Meeting of the American Chemical Society in Chicago and the TAPPI International Conference on Nanotechnology for the Forest Products Industry in Knoxville, TN.
PARTICIPANTS: Several students and post-graduate have been trained in this project including: Elvie Brown graduated with an MS in Chemical Engineering from WSU. Erica Rude graduated with an MS in Mechanical and Materials Engineering from WSU. Yu Geng was a post-doctoral fellow working on this project at WSU. Jinwu Wang graduated with PhD in Civil and Environmental Engineering at WSU. Cao Qi graduated with an MS in Civil and Environmental Engineering at WSU.
TARGET AUDIENCES: These efforts are of value to the forest products industry, in particular to the composite and adhesive industry that use or have interest in natural fibers. Furthermore the potential applications in the biomedical field for the newly developed materials can be benefic to society as a whole and may foster new practices in medecine.
Impacts
The findings developed in this project have broad impacts. For instance the novel approach to engineer bacterial cellulose nanocomposites is very interesting as it opens new avenues to design nanomaterials for critical biomedical applications such as blood vessel implants. The new knowledge generated in this area has led the researchers to further explore the field of cellulose based biomaterials for biomedical applications. The techniques developed here also have impacts in terms of providing new avenues for researchers to evaluate such complex materials. For instance, the possible utilization of CP/MAS NMR for deciphering nanometer scale interactions in composites was demonstrated in new composite systems.
Publications
- E. Brown and M.-P. Laborie. 2007. Bioengineering of bacterial cellulose/ polyethylene oxide nanocomposites, Biomacromolecules 8 (10) 3074-3081.
- B. Gupta, I. Reiniati and M.-P. Laborie. 2007. Surface properties and adhesion of wood fiber reinforced thermoplastic polymers, Colloids and Surfaces A: Physicochemical and Engineering Aspects 302 (1-3) 388-395.
- T. Hervillard, Q. Cao and M.-P. Laborie. 2007. Improving water resistance of wheat straw-based medium density fiberboards bonded with aminoplastic and phenolic resins, BioResources 2 (2) 148-156.
- M.C. Maranan and M.-P. Laborie. 2007. Analysis of hybrid poplar energy traits by NIR spectroscopy, Journal of Biobased Materials and Bioenergy 1 (1) 155-162.
- B. Gupta and M.-P. Laborie. 2007. Surface activation and adhesion properties of wood plastic composites, The Journal of Adhesion, 83 (11) 939-955.
- J. Wang, M.-P. Laborie and M.P. Wolcott. 2007. Application of beam mechanics to sensing the cure development of wood-phenolic joints by dynamic mechanical analysis, Thermochimica Acta , 465 (1-2) 18-24.
- J. Wang, M.-P. Laborie and M.P. Wolcott. 2007. Comparison of model-fitting kinetics for predicting the cure behavior of commercial phenol-formaldehyde resins, Journal of Applied Polymer Science 105 (3) 1289-1296.
- E. Brown 2007. Bacterial cellulose/thermoplastic polymer nanocomposites, MS thesis, Chemical Engineering, Washington State University. pp. 109
- E.F. Rude 2007. Evaluation of coupling mechanisms in wood plastic composites, MS thesis, Mechanical and Materials Engineering, Washington State University, pp. 92.
- J. Wang 2007 Cure kinetics of wood phenol-formaldehyde systems, PhD Disseration, Civil and Environmental Engineering, pp. 212.
- M.-P. Laborie. 2007. Applications of solid state nuclear magnetic resonance to probe the interphase in natural fiber reinforced composites, Proc. 28th Riso International Symposium on Materials Science, Interface Design of Polymer Matrix Composites- Mechanics, Chemistry, Modeling and Manufacturing. Ed. RB. R. Sorensen, L.P. Mikkelsen, H. Lilholt, S. Goutianos and F.S. Abdul-Mahdi, Riso National Laboratory, Roskilde, Denmark, Sept 3-6, p. 213-219.
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Progress 01/01/06 to 12/31/06
Outputs
A novel approach for designing nanoscale structures in lignocellulosic materials has been evaluated and novel cellulose nanocomposites thereby prepared. The approach consisted of integrating the bioproduction of bacterial cellulose with the mixing step in a polymer matrix, polyethylene oxide (PEO) in this case. Using this approach cellulose nanocomposites have been prepared in controlled PEO/cellulose weight ratios, having good fiber dispersion and also with controlled cellulose dimensions and nanocomposite morphology. In parallel, atomic force microscopy and dynamic mechanical analysis protocols have been developed to characterize the nanocomposites. It is expected that the performance of these cellulose nanocomposites can be tailored from the chemical composition and morphology.
Impacts
This integrative and interdisciplinary approach to lignocellulosic material designs sets an example of novel preparation avenues for the manufacture of cellulose based products with unique attributes and potential. In addition, the cellulosic materials are biodegradable but also biocompatible and therefore may find application in the biomedical field. This research has therefore positive environmental and societal applications.
Publications
- A morphological Study of the Wood/Phenol-formaldehyde Resin Interphase, Laborie M.-P., L. Salmen and C.E. Frazier. Invited. J. Adhesion Science and Technology (2006) 20, 8, 729.
- 13C CP/MAS NMR Study of a Wood/Phenol-Formaldehyde Resin Bondline, M.-P. Laborie and C.E. Frazier, Journal of Materials Science (2006) 41(18), 6001
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Progress 01/01/05 to 12/31/05
Outputs
The project's objective was to develop novel techniques for the molecular scale characterization of lignocellulosics composites. Solid-state NMR and viscoelastic modeling of relaxation in wood/phenolic composites have been developed. Additional modeling of phenolic cure kinetics has been performed. Both of these analyses provide a molecular understanding of structure and morphology in lignocellulosic composites.
Impacts
The molecular dynamic methods developed have given insight on the molecular scale interactions in these lignocellulosic composites. As such they provide a lense on the molecular origin of performance therefore enabling to molecularly design performance. For instance, the kinetic modeling of phenolics is an ideal tool to optimize the hot-pressing conditions of traditional wood-based composites for performance.
Publications
- Wang, J., M.P. Wolcott and M.P.Laborie. "Modeling the cure kinetics of Phenol-formaldehyde resins", Thermochimica Acta 439, 68, (2005).
- Laborie M.P. The Temperature Dependence of Wood Relaxations: a Molecular Probe of the Woody Cell Wall. In Characterization of the Cellulosic Cell Wall (2005). Eds. D. Stocke and L. Groom. Blackwell Publishing Ames, Iowa USA, 87.
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Progress 01/01/04 to 12/31/04
Outputs
Molecular scale investigations of wood/phenol-formaldehyde composites have been published. Namely the applicability of the cooperativity analysis to evaluate interphases in composites has been demonstrated. It has allowed for some insight on the molecular weight effect of phenolic resins on the wood adhesive interphase. Additionally, the nature of interactions between lubricants, coupling agents, thermoplastic and wood that are commonly used for wood plastic composites is investigated with solid state NMR. This technique helps determine the chemistry that is taking place between these components.
Impacts
The work published on wood/thermosetting systems proposes novel methods to evaluate interactions at the interphase. It contributes to the design of wood/adhesive interphases for improved adhesion. The work on wood plastic composites will help develop novel formulations of polymer/coupling agents/ lubricants for improved interactions and performance.
Publications
- Laborie M.P., C.E. Frazier, L. Salmen, 2004. Application of the Cooperativity Analysis to the in situ Glass Transition of Lignin, Holzforschung vol 58, pp. 129-133.
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Progress 01/01/03 to 12/31/03
Outputs
Two activities have been pursued in this project. First of all, methods and techniques are being sought to characterize the molecular scale morphology of lignocellulosic materials. The validity of novel viscoelastic models for lignocellulosic materials such as wood was communicated in a refereed article submitted to Holzforschung. Further fundamental studies involved the modeling of molecular motions in bio-based composites. It was found that the fiber orientation affected segmental relaxation of wood amorphous polymer suggesting a mechanical and or constraining effect of the fibers. The research results were presented at the North American Thermal Analysis Society Conference but also to a workshop on the cellulosic cell wall. More applied research on the molecular engineering of Lignocellulosic composites have dealt with the surface modification of wheat straw for compatibilization with aminoplastic resins in the framework of Medium Density Fiberboard Composites.
Various surface modifications were attempted to improve adhesion of wheat straw with aminoplastic resins. The modifications resulted in increased O/C ratios of the substrate but also in decreased silicon content. MDF composites from wheat straw were manufactured with aminoplastic resins and afforded mechanical properties above specifications for interior applications of MDF. Improvements are still being sought for other physical properties such as thickness swell and water absorption.
Impacts
The methods developed are important to gain better insight on the morphology and ultrastructure of natural biocomposites such as wood. With better characterization methods, novel tools are offered to design and optimize man-made composites from natural resources. These results are expected to help better utilize renewable resources for Materials development.
Publications
- No publications reported this period
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