New Bio Plastics and Resins

By Lorenz Bauer, PhD., Lee Consulting Enterprises

Special to The Digest

Sales of biopolymers and resins are predicted to grow to over $5 billion by 2021.   Biomass derived materials have been used neat and as components in composites and blends for the last decade. Products made with high contents of cellulose, starch, proteins, chitosan are common. New products made with biosynthetic products like polylactic acid (PLA) and polyhydoxylalkanotes (PHA) appear on regular basis in the press and on the shelf.       These products include beverage bottles, wood replacements, food packaging, 3D printing, grocery bags and many other applications. New formulations and additives that improve the properties of the biopolymers are being considered.   Some of the more significant develops in the biopolymer and plastics development in the past year are included the table below.

The latest trend is the production of monomers that can directly replace fossil derived materials in “drop in” polymers. Totally renewable carbon polyethylenes and polyesters are starting to emerge on the market. The other significant area of advancement is the use of CO₂ as a feedstock for urethanes foams.    These materials make polymers identical to those made with the nonrenewable monomers. Thus they are compatible with existing formulations and infrastructure greatly reducing the barrier their market acceptance.

The developments compiled in the table are divided into the following categories: drop in polymers made using BioSource materials, new biobased polymer replacements for non-bio materials, materials that use captured carbon dioxide, new totally biosourced composites, and high value biopolymers.  The many developments in the area of biopolymer blends and composites with non biobased materials to increase renewable content are not included in the table.

The year began with an announcement from DuPont Industrial Biosciences and ADM that they have jointly developed a process for producing furan dicarboxylic methyl ester (FDME) from fructose. The polytrimethylene furandicarboxylate (PTF) can be used with DuPont’s proprietary Bio-PDO (1,3-propanediol) to form a novel polyester that is suitable for manufacturing totally bio based beverage containers. Progress in using captured CO₂ to produce polymers continues with the announcement of a new product line by Covestro (Cardyon^TM) for inclusion into poly-urethanes. Corbion continues to aggressively market polylactic acid (PLA) as a neat bioplastic resin and has announced new materials made without the use of edible biomass

There continues to be a significant push towards the use of biomass derived plastics and resins in a wide variety of consumer products.   Pressure on the part of governments, particularly in the EU and California encourages the increased use of renewables.   Many of the major players in the plastic and resin industry have sustainability goals that will require the use of more bio-based products. They continue to encourage R&D efforts by off take agreements and joint ventures. A recent poll by the plastics trade group SPI found that, 57 percent of the people surveyed would probably or definitely be more likely to consider purchasing a plastic product with the U.S. Department of Agriculture’s Certified Biobased Product seal. Being viewed as environmental friendly is becoming a key product differentiation factor for consumer products.

Plastics are a value added product when compared with fuel. Even with current oil prices, fossil carbon derived thermoplastics are selling at gasoline equivalent price of between $4-8 per gallon. Biopolymers are more attractive than unsubsidized biofuel production.   Polylatic acid (PLA), the current leader in the bioplastic market sales volumes, is 20-50% more expensive than competing materials.   The higher costs are a major impediment to adoption of bioplastics.   Several producers have recently stopped production or left

Biopolymer and Resin Developments 8/2015-8/2016

Biopolymer area including Metabolix and Novamont .   This suppresses applications of the bioplastics because of lack of availability and secure vendors. However as applications increase, the economy of scale should lower prices.   Also, the growing development of advanced biomass conversion processes which use waste and no edible materials continues as part of the drive to renewable chemicals and fuel. The cost of the biopolymers should drop relative to fossil derived carbon. This may already have been the case for materials derived from succinic and adipic acid prior to the recent drop in oil prices.

Bioplastics are attractive because they are made from renewables and are perceived to have a lower environmental impact when they are disposed of properly. Many formulations decompose more rapidly than traditional polymer. The more rapid degradation decreases shelf life and may not translate into the desired reduction in the waste stream. Biopolymers in a waste stream can disrupt recycling efforts which in the short run is more efficient way of reducing carbonaceous waste.   Currently there is a debate over the standards and regulations that should be applied to give “green” certification. This controversy may delay adoption of the materials by some users.

The biodegradability of the biopolymers is a definite advantage in some biomedical applications.   Among the announcements in the table provided, are two by Merk and Evonik of reported their plans to market bio derived materials for implants and other medical use like scaffolds for tissue growth.

There are some applications where the biopolymers have significant advantages over other materials.   PLA polymers are particularly useful in 3D printing applications. PLA is widely used for making for household items, gadgets, and toys. It is better suited when flexibility is not a requirement. It is biocompatible with the human body and can be used for objects that are worn on the skin.

Due to its relatively low glass point, PLA is unsuitable for objects that are subject to heat: When exposed to 60ºC or more for some time, it loses its shape. You wouldn’t use PLA for objects that are exposed to direct sunlight for a prolonged time or that are placed in a car. It is also not suitable for kitchen equipment that is put into the dishwasher (at least not for dishwasher programs at 60ºC or more).

Bioplastics will only be widely applied if they have the properties desired by plastic and resins users. For example, one application of PLA packaging, was rejected because it made too much noise when it was opened.   Difficulty in meeting specifications for barrier properties, thermal stability, processability with current technology, flexibility, durability, the presence of trace by-products have arisen in some cases.  These have slowed acceptance of biopolymers.

Many polymer products use complex multicomponent formulations and complex processing procedures developed over many years.   This is the reason for the great interest in drop in materials that can use all of the prior art in formulation and production. There have been several announcements of products prepared with green polyethelene marketed by Braskem. The next trend in this area is to move to advanced biomass conversion that does not complete with food production for raw materials.

Market forces are also driving development of biobased materials as additives in formulations that include both renewable and nonrenewable sources.   Using the biopolymers allows a claim of “green” content and can facilitate degradation in composites piles and landfills.    Often these materials involve the use of fibrous cellulose or chitosan as additives with either PLA or nonrenewable polymers.

However, biopolymers and resins will not replace non-renewables in the near term. The higher costs will limit their use to areas were there “green” reputation enhances the perceived value of the product or where they have performance advantages.   As the prices of the biopolymers drop with increased production and the price of oil rises this situation is likely to change.   This why in the long term biopolymers will play an increasingly important role in the future.

Lorenz Bauer is a member of Lee Enterprises Consulting. Lee Enterprises Consulting is the world’s largest renewable chemical, bioenergy and biofuels consulting group, who have consultants and experts worldwide, including in the technologies discussed in this report. The opinions expressed in the report are those the authors, and do not, necessarily, express the views of Lee Enterprises Consulting.