Grantee Research Project Results
Final Report: Developing Sustainable Products Using Renewable Cellulose Fiber and Biopolymer Composites
EPA Grant Number: SU835524Title: Developing Sustainable Products Using Renewable Cellulose Fiber and Biopolymer Composites
Investigators: Lee, Young-A , Ghalachyan, Armine , Farr, Cheryl , Xiang, Chunhui , Ramasubramanian, Gauri , Kessler, Michael , Li, Rui , Madbouly, Samy , Wen, Zhiyou
Institution: Iowa State University
EPA Project Officer: Packard, Benjamin H
Phase: I
Project Period: August 15, 2013 through August 14, 2014
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2013) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Chemical Safety , P3 Awards , Sustainable and Healthy Communities
Objective:
To reduce the environmental impact of textile and apparel production, new composites would be developed by using renewable cellulose fiber and biopolymer obtained from agricultural products such as corn or soy. Academically diverse students from Iowa State University have been designing and evaluating the new product, half scale vest, developed from the composites having good tensile strength and relatively low moisture regain. This project is consistent with P3 benefits including a cleaner community environment, reduction in energy use, reduction of fiber processing and fabric production costs, reduction of material waste, and development of a textile that has potential for production beyond an experimental prototype.
Recent developments with sustainable biopolymers have the potential to be combined with the cellulose fibers to produce composite textiles with the cellulose fiber mats. To meet the technical challenge of combining the cellulose fibers grown in mats with sustainable biopolymers, innovative and inventive research has been employed. The purpose of the proposed project was to identify a method of growing and combining the cellulose fibers from bacteria and yeast in fermented tea with sustainable biopolymers obtained from agricultural plant products such as corn or soy, to reduce moisture regain and to increase strength of the cellulose fiber. New products developed from the composites would have good tensile strength and relatively low moisture regain which are the key parameters for regular daily wear.
The challenge would be the limitations of chemical compatibility with the cellulose molecule and the necessity to have all aspects of the product and processes sustainable. Development of a method to treat the cellulose fiber mat that provides a sustainable product includes treating the mat with a sustainable biopolymer that reduces moisture regain and increases tensile strength.
Two methods were proposed: 1) renewable cellulose fibers would be incorporated into biopolymer composites and 2) biopolymer nanoparticles dispersed in water would be added to bacteria and yeast in fermented tea during growing the cellulose fibers. The proposed development approach of sustainable vest using renewable cellulose fiber and biopolymer composites includes: 1) to document the specific ingredients and process for producing consistent cellulose fiber mats from bacteria and yeast in fermenting tea within an environmental sustainability context, 2) to identify the environmentally sustainable biopolymers compatible with the cellulose fibers mats, 3) to test the incorporation of the environmentally sustainable biopolymers with the cellulose fiber mats and to identify those methods that offer the greatest potential, 4) to test the properties of the composites developed from cellulose fiber mats and biopolymers that combine for reduced moisture regain and increased tensile strength, 5) to develop one prototype, vest, from the composites with higher strength and lower moisture regain, and 6) to evaluate the durability and wearability of the prototype.
Summary/Accomplishments (Outputs/Outcomes):
The successful completion of this project has been achieved using a multi-disciplinary approach in the material development, testing, and implementation of biopolymer composite materials to new product design. Graduate students were individually selected for this project based on their expertise in fiber, material, design, product development, and their ability to carry out research and planning towards the solution to develop regular daily wear using the new composite materials to have good tensile strength and relatively low moisture regain.
The first stage of the project involved various experimentations to identify the optimal protocol for consistent growth of cellulose fiber mats. To start the culture media for the cellulose growth, the following ingredients were used in a16x12x8 inch plastic container at a room temperature of 27-30°C: 3760 ml distilled water, 9 organic green tea bags, 540g granulated cane sugar, and 632 ml white vinegar and 100g of organic SCOBY. Cellulose fiber mats were visibly formed on the surface within a week and continued growing for another three week until being harvested. The mats were then thoroughly washed and boiled in deionized water to remove sugar residues and other impurities. The mats were air-dried at the room temperature of 27-30°C on a fiberglass screen wire on a flat surface. Several cellulose mats were air-dried without the purification process as a comparison with the purified samples. The comparison results prove that this purification process improves the material’s hand and properties. Both non-purified and purified samples had a leather-like appearance and texture; however, the purified mats were flexible, dry and pleasant to the touch, while the unpurified mats were flexible but very sticky to touch. The properties of these mats were tested in the various stages of this project to reduce moisture regain and tensile strength.
The next step of the project involved the development of cellulose/biopolymer composites to identify biopolymers compatible with the cellulose mats grown and to successfully develop composite mats with enhanced properties. The team tried to deep-coat small dry samples of cellulose mats in polylactic acid (PLA) and aqueous caster oil-based polyurethane dispersions (PUDs) with approximately 30 nm particle size. Uncoated and biopolymer coated samples, unpurified cellulose film mat subjected to dip-coating by PLA and an aqueous dispersion of PU, were examined using scanning electron microscopy (SEM) for imaging the surface and cross- sectional microstructure. Since the objective of coating the cellulose fibers with biopolymers was to make it water-resistant, but allow for a ventilated surface at the same time, the results show that the dip-coating method was probably not the best method to make our cellulose fiber mats as required. The cross-section of the washed samples provides a very interesting viewpoint, the cellulose film comprises of multiple layers about 1μm thick with a network of fibers on the surface of each layer as anticipated. This was a very encouraging result, and is attributed to the thorough purification of the samples that extract out any excess sugar or bacterial depositions on the cellulose.
Electro-spinning was considered as a more controlled way of depositing the biopolymer coating on cellulose films. Samples were coated with PUDs since the PLA did not provide a sufficiently adherent layer on the cellulose.
Tensile testing was also performed to examine the properties of the composites developed from cellulose fiber mats and biopolymers. The average tensile strength of the unpurified, non-coated samples is higher than the purified samples, which could be attributed to the fact that the presence of excess sugars in the layers providing reinforcement effect to the cellulose matrix that would be able to withstand a higher applied stress. The trend in the tensile stress at maximum or peak load shows that the PU-coated cellulose fiber mat is much stronger than the unpurified, non-coated version. This result proves that the processing of the fiber mat after its growth plays a very important role in dictating the mechanical properties.
To test water regains of the vest prototype, the team used a simple version of fabric moisture management test with the following three samples: unpurified, purified thin, and purified thick. No significant difference was found among all three samples regarding the diameters of the water drop before and after the test. This may be from our samples that have great ability to absorb the water, which results in the solidification of the water drop. In addition, the film-like, non-woven surface of the sample may also restrict the spread of the water because of the surface tension of the water drop.
The final stage objectives of the P3 Phase I project will be completed by disseminating results to the local community, the academic community, and small farmers and business in the state of Iowa and the United States. The results from this project will be presented at the 2014 International Textile and Apparel Association annual conference in November. Two manuscripts are also being generated (one focusing on fiber sciences and the other for the application of the composite materials to a new product design) and will be submitted to Green Chemistry and AATCC Research Journal, respectively.
Conclusions:
The project outputs include characterization of the developed composites (e.g., morphology, strength, moisture regain), sustainable product prototypes, evaluation of the products (e.g., durability, wearability), and the development of instructional materials. The project provided students with the opportunity to make connections among the source of raw materials, the processing needed to transform them into a new textile composite suitable for apparel, the impact of products and processes on the environment, and the potential for the process and the product being adapted to larger scale production. In an agricultural-focused state of Iowa, making the connection from farm to consumer has the potential for being transforming experience for the students and the faculty.
P3 Phase I project provided proof of concept that products developed using cellulose-based biocomposite materials can provide significant environmental and economic benefits. Successive experiments in part of the Phase I project revealed the broad capabilities of the biopolymer composite materials to develop various types of products by considering different end users. The cultivation process used to produce the cellulose fiber mat formed by bacteria and yeast in fermenting tea is an option that has the potential to yield a cellulose textile that could have little or no waste, is produced without fertilizers, irrigation, or farm equipment needed for the production of other cellulose fibers such as cotton. The tea medium can be reused after a layer of the fiber mat is harvested and if disposed of as waste, is non-toxic to the environment. As a cellulose fiber, the mat is biodegradable and compostable. It will not contribute to land fill issues.
Supplemental Keywords:
science, technology, innovation, teaching resource, consumerRelevant Websites:
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P3 Phase II:
Developing Sustainable Products Using Renewable Cellulose Fiber and Biopolymer Composites | 2015 Progress Report | 2016 Progress Report | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.