By: Barry Dean,
By: Barry Dean, Naperville, Illinois, USA BIOPLASTIC patents U.S. Patent 10,518,444 (December 31, 2019). “Compostable or biobased Foams”, Adam R. Pawloski, Jeffrey J. Cernohous, and Kent Kaske (Lifoam Industries LLC, Greer, South Carolina) This patent teaches a product by process where a foamed bead is formed based on a renewable polymer with a specific gravity of less than 0.15 g/cm3. The foamed renewable based bead is produced using a blowing agent that is not a volatile organic compound. The foamed bead can be further processed into a three dimensional article which represents designs suitable for packing, insulative sheet and the like. The renewable foamed bead can be processed using conventional equipment for extrusion and injection molding. The renewable foam can provide light weight options where structural performance is needed in applications such as automotive, home construction, electronic and general consumer articles. The patent claims renewable/compostable polymers including polylactic acid and its individual stereoregular structures, polyhydroxyalkanoates, polybutylene succinate, polybutylene adipate, polyglycolic acid as well as others all with a preferred melting point of less than 150 °C. The blowing agent (2 – 5 weight %) can be selected from water, carbon dioxide as well as metal carbonates, nitrogen, azodicarbonamide as well as mixtures. Nucleating agents for cell formation can be selected from talc, kaolin, silica and other traditional nucleating agents. Examples provided illustrates the process for making foamed polylactic acid beads using injected supercritical carbon dioxide resulting in foamed beads (2mm – 5 mm) with a closed cell structure and a cell size of 50 – 150 um. This section highlights recent IP (patent) activity that is relevant to the field of bioplastics. The information offered is intended to acquaint the reader with a sampling of know-how being developed to enable growth of the bioplastics and bioadditives markets. U.S. Patent 10,544,241 (January 28, 2020), “Farnesene- Based Macromoners And Methods of Making and Using The Same”, Steven K. Henning, Taejun Yoo and Herbert S. Chen (Fina Technology, Inc Houston, Texas) Farnesene consists of six closely related structures, all being sesquiterpenes but differing by location of a double bond and associated stereochemistry. This patent teaches using farnesene, a natural product to make a reactive material for radical polymerization by derivatizing farnesene into a macromonomer, a monfunctionalized long chain monomer which can be used to make comb and star polymers which in turn can be used as modifiers for lubricants, hydraulic fluids, adhesives and cosmetics. The patent teaches the methodology for converting a farnesene molecule to a polyfarnesene monofunctional alcohol, hydrogenating the polyfarnescene monofuctional alcohol at least in part and then reacting with an acrylate to render the reactive acrylate for the macromonomer. As a reactive additive, the polyfarnesene acrylate exhibits significantly lower viscosity (5 x to 25 x) at 25 °C versus a comparative polybutadiene acrylate. Low viscosity is a key point both for polymerization as well as use in lubricants, hydraulic fluids and adhesives. 48 bioplastics MAGAZINE [02/20] Vol. 15
U.S. Patent 10,526,301 (January 7, 2020), “Production of Purified Dialkyl-Furan-2,4-Dicarboxylate In A Retrofitted DMT Plant”, Kevin J. Fontenot, Mesfin Ejerssa Janke, Kenny R. Parker, and Ashfaq Shahanawaz Shaikh (Eastman Chemical Company Kingsport Tennessee) A process is taught for feeding 2,5- furandicarboxylic acid and an alcohol into an esterification reactor zone to form a dialkyl-2,5-furan dicarboxylate (DAFD) crude product where the esterification reactor is a commercial scale reactor previously used in the dimethylterephthalate (DMT) process. The DAFD monomer is the key monomer for enabling polyethylene furan dicarboxylate (PEF). There are three major costs in development and commercialization of a new material like PEF, research costs, development costs and capital costs. The teachings of this patent address a key commercialization cost, capital by enabling the use of a commercial reactor previously used to make DMT. The process teachings focus on a crude diester composition comprising dialkyl furan-2,5-dicarboxylate (DAFD), 5-(alkoxycarbonyl)furan-2-carboxylic acid (ACFA), alkyl furan-2-carboxylate (AFC) and alkyl-5-formylfuran-2- carboxylate (AFFC). U.S. Patent 10,435,557 (October 8, 2019). “High Heat Deflection Temperature Polylactic Acids with Tunable Flexibility and Toughness”, William J. Orts, Lennard F. Torres, Allison Flynn, and William Ketty (The United States of America by the Secretary of Agriculture and Lapol LLC (Santa Barbara, California) This patent teaches a polylactic acid composition that tunable mechanical properties. The composition consists of a polylactic acid stereocomplex (equal amounts of D and L enantiomers of PLA; a toughening agent and a polymeric additive which both plasticizes a and nucleates the PLA matrix. The PLLA and PDLA enantiomers exhibit melting temperatures of 170 – 190 °C and 180 – 200 °C, respectively; while the stereocomplex of the D and L enantiomer offers a melting temperature of ~ 230 °C which enhances (allows for tuning of) modulus and practical heat distortion temperature, ie end use temperature. The one drawback of the stereocomplex is reduced impact strength/ toughness. This invention teaches the use of more flexible biopolymers such as polybutylene succinate (PBS) and polybutylene adipate terephthalate (PBAT) to enhance (tune) the toughness of the stereocomplex. In addition a polymer polyester derived from triols, diols and a diacid is taught which serves as a compatibilizer, plasticizer and nucleant for the combined stereocomplex and flexible polymer. The process for making this polymer polyester is taught in U.S. Patent 9,139,689. The combination of the stereocomplex, flexible biopolymer and the polymer polyester illustrates the combination of high heat distortion temperature, practical toughness and balanced modulus allowing for this composition to perform as an engineering resin for intricate moldings and structural performance. U.S. Patent 10,526,461 (January 7, 2020), “Biodegradable Polyester Mixture” , Xin Yang, Jorg Auffermann, Carsten Sinkel, Jerome Lohmann, Robert Loos, Gabriel Skupin, Andreas Kunkel and Lars Borger ( BASF SE DE) Ref: WO2014/075997 This patent teaches a biodegradable polyester composition targeted to agricultural films; ie mulching, cover and slit tape films as well as selected textiles. The composition concept taught focuses on meeting DIN EN 13432 for compostable films and DIN EN ISO 17556 for aerobic soil biodegradation. The first polyester is a polybutylene sebacic acid terephthalate (PBSeT) where the diacid ratio is 40 – 70 weight % sebacic acid and 30 – 60 weight % terephthalic acid. The second polyester is a polybutylene adipate terephthalate where the diacid ratio is 40 – 70 weight % adipic acid and 30 – 60 weight % terephthalic acid (PBAT). The first and/or second polyester can have 0 – 2 weight % of trihydric alcohol substituted for a portion of 1, 4-butanediol. In addition the first and/or second polyester can contain a bifunctional diisocyanate chain extender. The first and second polyester combine to effect a composition of 80 – 90 weight % of the first polyester and 10 – 20 weight % of the second polyester. Note: Sebacic acid is an aliphatic linear diacid of 10 carbons. The biodegradable polyester composition can be further modified with a filler 10 – 35 weight % of a filler with calcium carbonate and/or talc being preferred. The biodegradable polyester composition can be further modified with starch and/or polyhydroxyalkanoate (5 – 45 weight %). The biodegradable polyester composition exhibits good Elmendorf tear strength, modulus, dart drop impact and highly efficient aerobic biodegradation performance. The aerobic biodegradation of the combined first and second polyester composition is better than the individual PBSeT and PBAT. bioplastics MAGAZINE [02/20] Vol. 15 49
