SUSTAINABLE PACKAGING BIO-BASED PLASTIC FILMS CONTAINING CELLULOSE NANOMATERIALS TO EXTEND FOOD SHELF LIFE

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: MCINTIRE-STENNIS
• Reporting Frequency: Annual
• Accession No.: 1017725
• Project Start Date: Nov 1, 2018
• Project End Date: Oct 31, 2023
• Program Code: [(N/A)]- (N/A)

Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824

Performing Department
Packaging

Non Technical Summary
Consumers and manufacturers are looking for sustainable packaging that can extend food shelf life due to the environmental issues associated with food waste and packaging waste. Increasing the use of bio-based materials in food packaging could address such concerns. However, moderate gas and poor moisture barrier properties of bio-based packaging materials need to be improved for these to perform equivalent or superior to conventional petroleum-based packaging materials in terms of food shelf-life extension. Thus, this project seeks to develop novel bio-based films that meet the desired properties by the food packaging industry of transparency, flexibility, and excellent barrier, while diminishing the loss of food quality and safety, and consequently maximizing freshness and shelf life of food. To achieve this goal, films that incorporate cellulosic nanomaterials (CNs) into poly(lactic acid) (PLA), a bio-based plastic from sustainable biomass resources, will be manufactured to form nanocomposite films with reduced gas and moisture permeation compared to neat PLA. The nanocomposite films developed here will result in a novel application of CNs with a tremendous potential for use in sustainable packaging applications.Thus, successful completion of this project will expedite the commercialization of cellulosic nanomaterials in food packaging applications. Additionally, the development of this new class of materials with novel properties will expand the range of applications and market competitiveness of crop-based and wood-based products. Therefore, the outcome of this project will increase the use of annually renewable crop (PLA is a corn-based plastic) for purposes other than food as well as increase utilization of wood and trees of low commercial value (CNs are from wood/trees), thus, providing new economic opportunities for agriculture and tree producers and processors to increase their income.

Animal Health Component

30%

Research Effort Categories

Basic

30%

Applied

30%

Developmental

40%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
511	0680	2020	100%

Knowledge Area
511 - New and Improved Non-Food Products and Processes;

Subject Of Investigation
0680 - Other products of the forest;

Field Of Science
2020 - Engineering;

Keywords

nanocomposite

cellulose nanocrystals

bio-based plastics

food shelf life

packaging properties

Goals / Objectives
This project seeks to develop novel, mono- and multi-layer bio-based films that meet the desired properties by the food packaging industry of transparency, flexibility, sealability, and excellent barrier, while diminishing the loss of food quality and safety, and consequently maximizing freshness and shelf life of food. The following key questions must be answered to meet the goal of proposed research project:How will the addition of cellulose nanocrystals (CNCs) into poly(lactic acid) (PLA) matrix and PLA/CNC nanocomposite film design (mono layer structure versus multi-layer structure) affect the sealing ability, barrier,and other physico-mechanical performance of PLA/CN films?Can CNCs be used to improve the performance of a bio-based material like PLA in extending the shelf life of packaged food?This research is intended to test the hypothesis that the addition of CNCs into PLA films could prolong the shelf life of packaged food and consequently, reduce food waste without negatively affecting the mechanical properties and sealing ability of PLA.

Project Methods
Design, Manufacture, and Property Evaluation of Mono- and Multi-Layer FilmsSince significant improvements of approximately 40% and 75% in water vapor permeability and oxygen permeability, respectively, were observed by adding only 1% CNC into PLA matrix, the amount of CNC will be fixed at 1% in all experiments conducted in this project.Two film configurations including (i) a mono-layer design and (ii) a multi-layer design will be manufactured and tested as described below:Firstly, monolayer films will be made using a cast extrusion process. A control (neat PLA) and and PLA/1%CNC films will be manufactured using processing conditions optimized from our previous studies.Secondly, multi-layer films consisting of an inner layer (PLA-1%CNC) and outer layers (neat PLA) will be manufactured using the cast-extrusion processing conditions optimized from our on-going studies. Multi-layer cast films will be assembled by co-extrusion of PLA-1%CNC nanocomposite films and neat (pure) PLA films. All CNCs will be contained in the inner layer.A so-called "multi-layer neat PLA without any CNC in the core layer" will also be manufactured using the same processing conditions and used as a control sample. This will eliminate the thermal history effect and allow a proper comparison with multi-layer films containing CNC in the core layer.Once manufactured, all films will undergo a variety of tests based on specific needs of packaging applications following procedures outlined in ASTM standards and/or described in our previous work. Important attributes for films intended for packaging applications include film transparency, barrier, and mechanical properties, among others. To test for film transparency, ultraviolet (UV)-vis reflectance spectroscopy and visual observation will be employed. Barrier properties, including permeability to H2O vapor and O2 at various relative humidities (0 to 100%) and temperatures will be determined. Packaging films must have a balance of strength and flexibility. Therefore, mechanical properties (tensile properties and dart impact strength) of the films will be evaluated using standardized test methods. Thermal evaluations, including DMA, DSC, and TGA tests will determine film thermal properties including storage modulus, loss modulus, glass transition and decomposition temperatures and will allow for a fundamental understanding of how the film performance relates to film designs. We also want to ensure that the CNCs are fully dispersed in the PLA. Therefore, films will be imaged using optical microscopy.Collected data will be statistically analyzed to identify the best performing nanocomposite films (mono- versus multi-layer) in terms of transparency, improved barrier and flexibility properties compared to neat polymer. Through the statistical methods, we will be able to correlate the film configuration with performance and use this knowledge to select the most performant films for shelf life study.Additionally, we will study the heat sealability of the manufactured films by measuring their burst pressure (pouches), seal strength (laminated strips), and hot tack strength. Sealing time (also known as the dwell time), sealing temperature, and sealing pressure will be the three primary (independent) variables to evaluate, whereas the burst pressure, seal strength, and hot tack strength will be the measured responses. These parameters influence the heat history at the interface and the extent of diffusion that occurs and our preliminary study showed that improper settings or control over these variables can negatively impact seal performance.After heat sealing, sealed specimens will be conditioned for at least 24 h before testing to ensure the seal has cooled to room temperature and crystallization has occurred. The seal strengths of films will be measured as function of the three primary sealing variables using a peel test on 25.4 mm width seal bar specimens according to the procedures outlined in ASTM standards (F2029e08 and F88/F88M-09). Burst test will be used to the internal pressure a pouch can withstand by filling it with air until it ruptures (or bursts) following the approach described in our previous study. An automated hot tack device will be used to measure the hot tack following the procedures outlined in ASTM standards (F1921/F1921M-12). Since seal strengths as well as the mode of seal failures (adhesive or cohesive) will be recorded over ranges of three primary heat sealing variables, it will be possible to construct a heat seal curve of seal strength versus sealing temperature, for different dwell times and seal pressures. These heat seal curves will provides information about performance and operating or practical heat seal temperature window of the films. Similarly, hot tack curves, i.e., plots of hot tack strengths versus seal bar temperatures at different dwell times and seal pressures will be constructed. The breadth of the hot tack temperature range will be determined from the curves, which will provide information regarding the operational window for the quality of the seal to withstand the stresses (hot tack) during FFS operations.Successful completion of sealing study will result in a fundamental understanding of how the addition of CNCs and heat sealing processing conditions affect the strength and integrity of the seals. This knowledge will lead to the determination of sealing conditions needed to produce pouches for packaging food needed in the shelf life studies.Shelf Life Study of Packaged CrackersThis part of the project will focus on assessing the effectiveness of the best performing nanocomposite film and its neat PLA counterpart developed above on extending the shelf life of crackers, which are water-sensitive products. Additionally, a commercial film used to package the crackers will be used as blank for comparison.The unpackaged crackers will be stored in a controlled temperature (25oC in the oven) and various relative humidity (RH) environments. Six different saturated salt solutions will used in the desiccators to provide six different RH conditions (11 to 92%). These desiccators will be placed in the oven set at 25oC. Unpackaged crackers will be weighed daily over a month period to determine the percent moisture gain/loss. The initial moisture content (IMC) and equilibrium moisture content (EMC) will be determined from the data and the experimental moisture sorption isotherm (EMC vs RH) will be built and compared to the isotherms predicted from various existing mathematical models such as linear, quadratic, cubic, and Guggenheim-Anderson-de Boer (GAB). This comparison will identify the model that best fits the experimental moisture sorption isotherm, which will then be used to estimate the EMC at any RH in the range of RH investigated.This will be followed by testing the shelf life of packaged crackers. Pouches from neat and PLA/CNC films will be made by first heat sealing the bottom of the films, followed by filling with crackers, and then sealing its top. The packaged crackerswill then be stored in a controlled temperature (25oC in the oven) and various relative humidity (RH) environments as described above and will be weighed every day over a month period to determine the percent moisture gain/loss. For each relative humidity, plots of moisture content versus time will be obtained from which the time to reach the critical moisture content (~8% from the literature) will be estimated as the shelf life of packaged crackers at that specific RH. This shelf life obtained experimentally will be compared to the one obtained from various existing models such as linear, log, middle-point and GAB in order to identify the best model that could predict the shelf life of crackers at any RH.

Progress 10/01/20 to 09/30/21

Outputs
Target Audience:The findings of this research have been shared with packaging companies interested in improving the shelf life of foods. Also, they have been disseminated to the broader scientific community through publications in scientific journals and presentations at national and/or international annual conferences on biomaterials so that they are available to farmers, companies, public, and scientific community interested in sustainable biomaterials from plants. The information gathered during this research is also being incorporated into a graduate course on materials taught at MSU. They are used as examples in a course taught by Dr. Matuana at MSU (PKG 825-Polymeric Packaging Materials) and other universities. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During this reporting period, this research project provided training and/or professional development to the following individuals at Michigan State University: four graduate students [Ms. Sonal Karkhanis (Ph.D.); Ms. Dangkamol Wongthanaroj (M.S); Mr. Krishnaa Venkatesan (M.S.); and Ms. Madhumitha Natarajan (M.S.)]. How have the results been disseminated to communities of interest?Peer reviewed journal publication and conference meetings. What do you plan to do during the next reporting period to accomplish the goals?The goals to be accomplished during the next reporting period include: (i) preliminary study on the manufacture of monolayer and multi-layer PLA/CNC composites films using cast extrusion process and their property evaluation; and (ii) study on the effectiveness of laminated PLA/CNC films to extend the shelf life of moisture- and oxygen-sensitive foods.

Impacts
What was accomplished under these goals? The research question # 1 is still under investigation. So far we evaluated the influence of cellulose nanocrystals (CNCs) addition levels (0 to 2 wt%) on the surface texture, thickness, and barrier properties of poly(lactic acid) (PLA) extruded-cast films and the results have been published in various peer-reviewed journals as mentioned in previous progress reports. The follow up study assessed the effect of CNC addition levels (0 to 2 wt%) on the sealing and mechanical properties of (PLA) cast films manufactured through a continuous extrusion melt-process. The sealing performance, i.e., the hot tack strength and seal strength of PLA films as well as the burst pressure of PLA pouches, significantly improved by adding up to 1% CNC into PLA matrix. Significant improvements in the tensile strength and modulus were also achieved by adding up to 1% CNC into PLA matrix. Nevertheless, these occurred at the expense of ductility, results supported by the dart impact strength showing that PLA/CNC composite films were more brittle than neat PLA films. A manuscript is under preparation and will be submitted to a peer review journal very soon. Additionally, we extended the concept of using CNCs to improve the barrier performance of plastics to other polymer matrices. Recent publication has demonstrated that CNCs improves the oxygen and carbon dioxide barrier properties of sugarcane-based linear low-density polyethylene (LLDPE) plastic (https://doi.org/10.1002/app.51515). For research question # 2, the potential of PLA/CNC films to extend the shelf life of moisture-sensitive foods has also been demonstrated and the findings published in a peer-reviewed journal (https://doi.org/10.1016/j.fpsl.2021.100689). Similarly, we completed the work on the application of PLA/CNC films to for the preservation of oxygen-sensitive (a MS Thesis was defended on Dec. 10, 2021) and a manuscript will be submitted for review very soon.

Publications

• Type: Journal Articles Status: Published Year Published: 2021 Citation: R.A. Lafia-Araga, R. Sabo, O. Nabinejad, L. Matuana, N. Stark, Influence of Lactic Acid Surface Modification of Cellulose Nanofibrils on the Properties of Cellulose Nanofibril Films and Cellulose NanofibrilPoly(lactic acid) Composites, Biomolecules 2021, 11, 1346 (2021). https://doi.org/10.3390/biom11091346
• Type: Journal Articles Status: Published Year Published: 2021 Citation: M. Natarajan, R.C. Sabo, N.M. Stark, and L.M. Matuana, Improving Gas Barrier Properties of Sugarcane-Based LLDPE with Cellulose Nanocrystals, Journal of Applied Polymer Science, 139 (3): Paper 51515 (2022). https://doi.org/10.1002/app.51515
• Type: Journal Articles Status: Published Year Published: 2021 Citation: K.B. Venkatesan, S.S. Karkhanis, and L.M. Matuana, Microcellular foaming of poly(lactic acid) branched with food-grade chain extenders, Journal of Applied Polymer Science, 138 (29) Paper 50686. August 5, 2021. https://doi.org/10.1002/app.50686
• Type: Journal Articles Status: Published Year Published: 2021 Citation: S.S. Karkhanis, N.M. Stark, R.C. Sabo, and L.M. Matuana, Potential of extrusion-blown poly(lactic acid)/cellulose nanocrystals nanocomposite films for improving the shelf-life of a dry food product, Food Packaging and Shelf Life, Volume 29, Paper 100689, September 2021, https://doi.org/10.1016/j.fpsl.2021.100689.
• Type: Theses/Dissertations Status: Published Year Published: 2021 Citation: Dangkamol Wongthanaroj, Application of Poly (Lactic Acid)/Cellulose Nanocrystal Nanocomposite Films for the Preservation of Oxygen-Sensitive Food, Master of Science Thesis, Packaging, 117 pp, Michigan State University, 2021.
• Type: Theses/Dissertations Status: Published Year Published: 2021 Citation: Madhumitha Natarajan, Improving Gas Barrier Properties of Sugarcane-based LLDPE with Cellulose Nanocrystals, Master of Science Thesis, Packaging, 104 pp, Michigan State University, 2021.
• Type: Theses/Dissertations Status: Published Year Published: 2020 Citation: Krishnaa Balaji Venkatesan, Microcellular Foaming of Poly(Lactic Acid) Branched with Food-Grade Chain-Extenders, Master of Science Thesis, Packaging, 111 pp, Michigan State University, 2020.
• Type: Theses/Dissertations Status: Published Year Published: 2020 Citation: Sonal Sanjay Karkhanis, Poly(Lactic Acid)/Cellulose Nanocrystal Composite Blown Films for Food Packaging Applications, Doctor of Philosophy Dissertation, Packaging, 210 pp, Michigan State University, 2020.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:The findings of this research have been shared with packaging companies interested in improving the shelf life of foods. Also, they have been disseminated to the broader scientific community through publications in scientific journals and presentations at national and/or international annual conferences on biomaterials so that they are available to farmers, companies, public, and scientific community interested in sustainable biomaterials from plants. The information gathered during this research is also being incorporated into a graduate course on materials taught at MSU. They are used as examples in a course taught by Dr. Matuana at MSU (PKG 801-Packaging Materials; PKG 825-Polymeric Packaging Materials) and other universities. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During this reporting period, this research project provided training and/or professional development to the following individuals at Michigan State University: One post-doc (Dr. Omid Nabinejad), one visiting scientist (Dr. Ruth Anayimi Lafia-Araga), four graduate students [Ms. Sonal Karkhanis (Ph.D.); Ms. Dangkamol Wongthanaroj (M.S); Mr. Krishnaa Venkatesan (M.S.); and Ms. Madhumitha Natarajan (M.S.)] as well as Ms. Lindsay Jessmore, the undergraduate student. How have the results been disseminated to communities of interest? Peer reviewed journal publication and conference meetings. P3Nano-US Endowment for Forestry and Communities Annual Meeting held at USDA Forest Service, Forest Products Laboratory in Madison, WI. What do you plan to do during the next reporting period to accomplish the goals?The goals to be accomplished during the next reporting period include: (i) preliminary study on the manufacture of monolayer and multi-layer PLA/CNC composites films using cast extrusion process and their property evaluation; and (ii) study the effectiveness of PLA/CNC composite films to extend the shelf life of oxygen-sensitive food.

Impacts
What was accomplished under these goals? The research question # 1 is still under investigation. So far we evaluated the influence of cellulose nanocrystals (CNCs) addition level (0.5 to 2 wt%) on the surface texture, thickness, and barrier properties of poly(lactic acid) (PLA) extruded-cast films and the results have been published in a peer-reviewed journal: (Liu, Y., & Matuana, L. M. (2019). Surface Texture and Barrier Performance of Poly(Lactic Acid)/Cellulose Nanocrystals Extruded Cast Films. Journal of Applied Polymer Science, 136(22), article 47594 (10 pages). doi: 10.1002/app.47594). The follow up study assessed the effect of cellulose nanocrystals (CNCs) addition (0.5 to 2 wt%) on the sealing and mechanical properties of (PLA) cast films manufactured through a continuous extrusion melt-process. The sealing performance, i.e., the hot tack strength and seal strength of PLA films as well as the burst pressure of PLA pouches, significantly improved by adding up to 1% CNC into PLA matrix. Significant improvements in the tensile strength and modulus were also achieved by adding up to 1% CNC into PLA matrix. Nevertheless, these occurred at the expense of ductility, results supported by the dart impact strength showing that PLA/CNC composite films were more brittle than neat PLA films. A manuscript is under preparation and will be submitted to a peer review journal very soon. For research question # 2, the potential of PLA/CNC films to extend the shelf life of moisture-sensitive foods has been demonstrated. A US Provisional patent has been filed and the following manuscript is under review in Food Packaging and Shelf Life journal: (Sonal S. Karkhanis, Nicole M. Stark, Ronald C. Sabo, and Laurent M. Matuana "Potential of extrusion-blown poly(lactic acid)/cellulose nanocrystals nanocomposite films for improving the shelf-life of a dry food product").

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Karkhanis, S. S., & Matuana, L. M. (2019). Extrusion Blown Films of Poly(lactic acid) Chain-Extended with Food Grade Multifunctional Epoxies. Polymer Engineering & Science, 59(11), 2211-2219. doi: 10.1002/pen.25224
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Liu, Y., & Matuana, L. M. (2019). Surface Texture and Barrier Performance of Poly(Lactic Acid)/Cellulose Nanocrystals Extruded Cast Films. Journal of Applied Polymer Science, 136(22), article 47594 (10 pages). doi: 10.1002/app.47594
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Sabo, R. C., Nabinejad, O., Stark, N. M., Lebow, P., Karkhanis, S. S., & Matuana, L. M. (2020). Novel Method of Compounding Cellulose Nanocrystal Suspensions into Polylactic Acid and Polyvinyl Acetate Blends. Proceedings, SPE-ANTEC, Annual Technical Conference, Society of Plastics Engineers, March 30-April 2, 2020, San Antonio, TX., 6 pages
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Karkhanis, S. S., & Matuana, L. M. (2019). Processing of Poly(Lactic Acid) Blown Films with Food Grade Chain Extenders for Packaging Applications. Proceedings, SPE-ANTEC, Annual Technical Conference, Society of Plastics Engineers, March 18-20, 2019, Detroit, MI., 6 pages.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Sabo, R. C., Stark, N. M., Wei, L., & Matuana, L. M. (2019). Wet Compounding of Cellulose Nanocrystals into Polylactic Acid for Packaging Applications. Proceedings, SPE-ANTEC, Annual Technical Conference, Society of Plastics Engineers, March 18-20, 2019, Detroit, MI., 5 pages.
• Type: Journal Articles Status: Submitted Year Published: 2020 Citation: Krishnaa B. Venkatesan, Sonal S. Karkhanis, and Laurent M. Matuana, Microcellular foaming of poly(lactic acid) branched with food-grade chain extenders, Journal of Applied Polymer Science
• Type: Journal Articles Status: Under Review Year Published: 2020 Citation: Sonal S. Karkhanis, Nicole M. Stark, Ronald C. Sabo, and Laurent M. Matuana Potential of extrusion-blown poly(lactic acid)/cellulose nanocrystals nanocomposite films for improving the shelf-life of a dry food product, Food Packaging and Shelf Life
• Type: Theses/Dissertations Status: Published Year Published: 2020 Citation: Krishnaa B. Venkatesan, "Microcellular foaming of Poly(Lactic acid) branched with food-grade chain-extenders," MS Thesis, School of Packaging, Michigan State University, 112 pages (2020).https://orcid.org/0000-0003-3718-5371

Progress 11/01/18 to 09/30/19

Outputs
Target Audience:The findings of this research have been shared with packaging companies interested in improving the shelf life of foods. Also, they have been disseminated to the broader scientific community through publications in scientific journals and presentations at national and/or international annual conferences on biomaterials so that they are available to farmers, companies, public, and scientific community interested in sustainable biomaterials from plants. The information gathered during this research is also being incorporated into a graduate course on materials taught at MSU. They are used as examples in a course taught by Dr. Matuana at MSU (PKG 825-Polymeric Packaging Materials) and other universities. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During this reporting period, this research project provided training and/or professional development to the following individuals at Michigan State University: four graduate students [Ms. Sonal Karkhanis (Ph.D.); Ms. Yuzhu Liu (M.S); Mr. Krishnaa Venkatesan (M.S.) and Ms. Madhumitha Natarajan (M.S.))] as well as the following undergraduate students: Ms. Lindsay Jessmore and Ms. Ms. Haley Ferer. How have the results been disseminated to communities of interest? Peer reviewed journal publication and conference meetings. P3Nano-US Endowment for Forestry and Communities Annual Meeting held at USDA Forest Service, Forest Products Laboratory in Madison, WI. What do you plan to do during the next reporting period to accomplish the goals?The goals to be accomplished during the next reporting period include: (i) evaluation of mechanical properties (tensile and dart impact) and other physical properties [water and gas barrier properties as function of temperature and relative humidity, refractive index, morphology (FE-SEM), surface roughness (AFM)] of extrusion-blown PLA/CNC composites films; (ii) preliminary study on the manufacture of multi-layer PLA/CNC composites films using cast extrusion process and their property evaluation; and (iii) study on the effectiveness of PLA/CNC composite films to extend food shelf life.

Impacts
What was accomplished under these goals? The influence of cellulose nanocrystals (CNCs) addition level (0.5 to 2 wt%) on the surface texture, thickness, and barrier properties of poly(lactic acid) (PLA) extruded-cast films was assessed. Irrespective of CNC content, addition of CNC increased surface average roughness and maximum roughness of PLA films in both machine and cross machine directions due to the presence of CNC agglomerates. Increased roughness resulted in films with uneven thickness, which affected its accurate measurements with a conventional micrometer. Rather, accurate thickness measurements were obtained through the density method, the more appropriate thickness measurement method for films with rough surfaces. The permeability values negatively correlated with the increased crystallinity. Both water vapor and oxygen permeability values decreased significantly by approximately 26-45% and 25-50%, respectively, as CNC content increased from 0.5 to 2 wt% because of the tortuosity effect. The oxygen permeability values of neat PLA and composite films remained insensitive to changes in the relative humidity (0 to 75%) when tested at 23oC. The feasibility of PLA/CNC films to extend the shelf life of moisture and oxygen-sensitive foods has also been investigated. A US Provisional patent has been filed based on our preliminary results, which have demonstrated that these films havestrong potential in extending the shelf life of food.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Karkhanis, S. S., Stark, N. M., Sabo, R. C., & Matuana, L. M. (2018). Water Vapor and Oxygen Barrier Properties of Extrusion-Blown Poly(lactic acid)/Cellulose Nanocrystals Nanocomposite Films. Composites Part A: Applied Science and Manufacturing, 114, 204-211. doi: doi.org/10.1016/j.compositesa.2018.08.025.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Karkhanis, S. S., Stark, N. M., Sabo, R. C., & Matuana, L. M. (2018). Performance of Poly(Lactic Acid)/Cellulose Nanocrystal Composite Blown Films Processed by two Different Compounding Approaches. Polymer Engineering & Science, 58 (11): 1965-1974. doi: 10.1002/pen.24806.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Liu, Y., & Matuana, L. M. (2018). Surface Texture and Barrier Performance of Poly(Lactic Acid)/Cellulose Nanocrystals Extruded Cast Films. Journal of Applied Polymer Science, 136(22), article 47594 (10 pages). doi: 10.1002/app.47594
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Wei, L., Agarwal, U. P., Matuana, L. M., Sabo, R. C., & Stark, N. M. (2018). Performance of High Lignin Content Cellulose Nanocrystals in Poly(lactic acid). Polymer, 135, 305-313. doi: 10.1016/j.polymer.2017.12.039.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Stark, N. M., Wei, L., Sabo, R. C., Reiner, R. R., & Matuana, L. M. (2018). Effect of Freeze-Drying on the Morphology of Dried Cellulose Nanocrystals (CNCs) and Tensile Properties of Poly(lactic) Acid-CNC Composites. SPE-ANTEC Paper, Annual Technical Conference, Society of Plastics Engineers, May 7-11, 2018, Orlando, FL., 5 pages.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Karkhanis, S. S. & Matuana, L. M. (2018). Processing of Poly(Lactic Acid) Blown Films with Food Grade Chain Extenders for Packaging Applications. SPE-ANTEC Paper, Annual Technical Conference, Society of Plastics Engineers, March 18-20, 2019, Detroit, MI., 6 pages.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Sabo, R. C., Stark, N. M., Wei, L., & Matuana, L. M. (2018). Wet Compounding of Cellulose Nanocrystals into Polylactic Acid for Packaging Applications. SPE-ANTEC Paper, Annual Technical Conference, Society of Plastics Engineers, March 18-20, 2019, Detroit, MI.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Wei, L., Agarwal, U., Matuana, L. M., Sabo, R. C., & Stark, N. M. (2018). Lignin-caused Performance Improvements of Poly(Lactic Acid)/CNCs Composites. Abstracts of Papers of the American Chemical Society, 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, New Orleans, LA. March 18-22, 2018., 255(Accession Number: WOS:000435537703034), Meeting Abstract 367. ISSN: 0065-7727.
• Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Yuzhu Liu, "Processing and Property Evaluation of Poly(Lactic Acid)/Cellulose Nanocrystals Extruded Cast Films," Master of Science Thesis, School of Packaging, Michigan State University, 136 pages, 2018.