Program Overview and Workflow
As the world moves increasingly towards bio-based technologies, it is necessary to address the barriers impeding wide-spread use of biopolymers and biocomposites. These involve a new set of challenges for the polymer and composites world, including the high cost of biopolymer synthesis, biopolymer property limitations, incompatibility of hydrophilic/hydrophobic surfaces in biofiber reinforced polymers, and inadequate translation of biofiber properties to the biocomposite. Attacking these inter-related biomaterial challenges requires an integrated, cross-disciplinary approach. The chart above illustrates the integration and flow of activities in the CNAM-Bio Center. There are two main programs within the center: Polymer Biosynthesis and Bioprocessing and Biopolymer/Biocomposite Processing and Manufacturing. The processing and manufacturing group uses both commercially available biopolymers and center-derived microbial biopolymers and nanocellulose.
Program Elements
1. Biopolymers from agricultural waste biomass
- Identify and/or engineer thermophilic microbial strains that can efficiently breakdown lignocellulose without expensive pretreatment and produce biopolymers (primarily polyhydroxyalkanoates, PHAs).
- Take advantage of the faster kinetics of high temperature processing enabled by utilization of thermophiles.
- Increase biopolymer yields using genome editing, electrocatalytic, and electrochemical approaches.
- Scale-up bioreactor production of PHAs to kilogram quantities for utilization in polymer processsing studies (item 5).
2. Biopolymers from methane
- Develop recombinant strains to produce PHAs from unpurified methane at high yields.
- Scale-up bioreactor production of PHAs to kilogram quantities for utilization in polymer processsing studies (item 5).
3. Engineering biopolymer properties
- Characterize the rheological, microstructural, thermal and mechancial properties of the microbial PHAs produced.
- Engineer polymer structure (monomer composition, side chain structure, etc.), and resulting properties, through genetic engineering strategies.
- Provide interactive input to the polymer processing investigations (item 5).
4. Nanocellulose from biomass
- Eliminate the use of strong, high-cost solvents for extraction of nanocellulose from biomass, reducing processing costs and enhancing nanocellulose quality.
- Produce targeted enzyme cocktail for removal of lignin, pectin and xylan via a thermopilic microbe found to efficiently degrade biomass.
- Assess dispersion properties of the nanocellulose in polymers and biopolymers (see also item 6).
5. Biopolymer processing
- Study polymer processing of new biopolymers and design effective processing conditions for extrusion, injection molding, thermoforming, etc.
- Explore polymer blends and effects of additives.
- Provide interactive input to the biopolymer property engineering studies (item 3).
6. Biocomposite processing and manufacturing
- Apply CNAM’s DiFTS process to the production of natural fiber (flax, hemp, bamboo….) thermoplastic polymer and biopolymer composites, with detailed exploration of processing variables and resulting mechanical and impact properties.
- Use processing flexibility of the CAPE Lab’s Thermoplastic Impregnation Machine (CAPE-TIM) to produce high-quality, continuous-fiber thermoplastic tapes/sheets from natural fiber yarns and fabrics, with both biopolymers and petroleum-based polymers.
- Systematically evaluate fiber/polymer interface, wet-out, and interfacial failure characteristics.
- Evaluate innovative and commercial sizing formulations for enhanced interfacial adhesion.
- Explore processing and properties of nanocellulose-reinforced biopolymers and mutiscale (natural-fiber/nanocellulose) reinforced biopolymers (with focus on nanocellulose produced in item 4).
- Explore hybrid (natural and synthetic) fiber combinations.
7. Advanced characterization
- Apply TEM, SEM, FTIR, Raman, LC-MS, AFM, EDX, WAXS, XPS, PALM, Micro X-Ray CT, rheometry, DMA, DSC, TGA, and other techniques.
- Combine scanning probe, fluorescence, and electron microscopies to elucidate the nanoscale architecture of lignicellulosic substrates.
- Combine PALM with AFM to map nanomechanical and spatio-chemical distributions of bioactive components of lignocellulosic substrates and associated biopolymers.
- Use advanced characterization techniques to help elucidate biological pathways for biopolymer biosynthesis.