Unfolded B-sheets of Protein Segments
Crosslinked to Polymer Chain
In the reactive extrusion process, a polymer grafted cross-linking agent creates a chemical bond between the virgin thermoplastic polymer and the soy bio-feedstock. Red, green and blue are polar residues, and white is non-polar residue. The figure in the insert in the upper left corner is a fluorescent microscopy image produced by Battelle confirming the excellent dispersion and thermal stability of our product.
Minimized Energy Conformation of Soy Bio-Feedstock Before Processing.
Biobent offers an award winning technology replaces 30%-40% of the petroleum required to make thermoplastics with a low-cost bio-feedstock derived from agricultural waste and co-products.
Bio-based fillers and plant-oil based polymers are not new. Unfortunately price and performance have never allowed for broad production and distribution of these types of thermoplastics. Biobent Polymers has found a way around this.
Oil extraction from grains results in such co-products as hull, flour, protein and meal. Generally, these co-products are isolated and purified to separate proteins and carbohydrates for later use as surfactants, rheology modifiers, fillers etc. However, isolating proteins and carbohydrates from agricultural co-products is a very expensive process. As a result, commercialization and practical use of polymer composites containing agricultural co-products has never been a success to date.
Biobent has developed an innovative method of using agricultural co-products without any purification step. The process uses a carbohydrate-protein interaction to unfold the protein molecular architecture, followed by reactive extrusion with commercially available thermoplastic polymer. Our process uses bio-feedstocks that cost 1/10th the price of the thermoplastic they are replacing, allowing Biobent to pass along savings that range from 2% to over 18%. Note: Cost savings are based on the percent of bio-feedstock loading that is achievable with each polymer type and the customer's cost per pound for their current virgin thermoplastic.
Bio-composites reported in prior art (other patent claims) did not have both protein and carbohydrates, making a direct comparison to Biobent bio-composites impossible. Furthermore, previously developed protein-based bio-composites required excessive amounts of plasticizer to unfold the protein, which adds to the cost and adversely affects polymer performance.
In addition to having the right bio-feedstock composition, dispersion of these bio-feedstocks is of critical importance.
Improper dispersion causes agglomeration of the bio-feedstock. This agglomeration reduces the amount of bio-feedstock that is available for crosslinking, compromises mechanical properties, impacts operational performance, is visible to the human eye and makes bio-composite thin films noticeably rough in texture.
The original technology used to produce a bio-composite was based on soybean co-products and polypropylene. Since the original invention, Biobent has expanded this process to work with a wide variety of polymers including homo and copolymer polypropylene, polyethylene (high density, low density, linear low density and ultra high molecular weight), TPO (a rubberized PP), PBS (a non bio-based biodegradable thermoplastic) and even other bioplastics such as PHA and PLA.
To further demonstrate the efficacy of this patented process, technical
tracks are underway with ABS (a very rigid plastic used for auto dashboards,
computer cases, etc.), and flexible PVC (used for cove molding (baseboards
in commercial buildings) and other flexible.
In addition to working with other thermoplastics, Biobent has done
extensive research on non-soy bio-feedstocks with carbohydrate-protein-
cellulosic ratios that are similar to soy meal. To date, Biobent has qualified,
three other bio-feedstocks that produce performance results that are on par with soy; canola (rapeseed meal after oil removal), agave (leftovers from the tequila manufacturing) and algae (biomass leftover from algal fuel oil production and specialty molecule extractions).
While viable bio-feedstock solutions, low cost, low value soy in the form of “spent soy flake” (reduced protein soymeal) has been determined to be the best overall bio-feedstock.
Lower sugars reduce discoloration (“carmelizing”), allow for easier colorization and reduce odor during compounding and converting (plastics manufacturing).
Higher amounts of protein seem to be un-utilized, which means they are protected by the “barrier assistance” described above. This un-linked material anecdotally appears to cause poorer mechanical performance, resulting in decreases in strength (stress) and strain.
Light in color allowing for easier colorization.
While bio-feedstocks such as canola meal and algae are inherently dark, and therefore only usable in applications requiring black polymers. That said, colorants are expensive, costing 20 to 50 times more expensive than the thermoplastics themselves. Therefore, even with low "loading ratios" of 50:1 (2%) to 100:1 (1%), a $50/pound black colorant @ 1% loading will increase the thermoplastic cost per pound by an additional $0.50!
With canola and algae, almost jet black bio-composite polymers can be produced using 0% colorant.
Biobent continues to look at optimum protein levels, optimum carbohydrate-protein-cellulosic ratios, and other bio-feedstocks with have similar compositions.
Professor Pat Woodward of the Ohio State University Chemistry Department OSU describes this innovation as follows: “The chemistry employed in this process is very clever. They have demonstrated unfolding the protein molecular architecture in single step using a unique chemistry/process control. This allows protein stability to be maintained during processing, and also favors the interaction between hydrophilic agricultural co-products and hydrophobic polymer segments”.