Process for The Low Cost and Non-Toxic Isolation of Cellulose Nanofibers from Grass Biomass

Cellulose nanofibers are a class of nanocellulose that are favored in materials applications because of their desirable chemical, mechanical, and environmental properties. However, the isolation of these materials from biomass remains a challenge because of toxic chemicals and high-energy specialized machines required. The inventors have developed a new process to isolate cellulose nanofibers from the well characterized grass biomass source miscanthus X. Giganteas. The process uses cheap, non-toxic chemicals, does not require any mechanical treatment, and produces materials with enhanced properties.

Inventor: Stuart Rowan

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Biodegradable Lactose-Based Hydrogel

Applying green chemistry principles, researchers at the University of Minnesota have developed a simple, novel method for the preparation of hydrogels composed of lactose containing polymers. This method involves an environmentally friendly, atom-economical reaction conducted in water to synthesize lactose-based methacrylic monomers, and methacrylic acid as a byproduct. This method allows for synthesis of the hydrogel through a simple pH adjustment of the reaction mixture followed by photopolymerization. In addition to the light-induced polymerization, the entire process is carried out in a single pot, making this process highly energy efficient, enabling synthesis at ambient temperature, and polymerization at high rates. The researchers have demonstrated that the water uptake, rheological and other physical properties can be tuned easily by varying the ratio of methacrylic anhydride to lactose. In addition, the process was shown to produce hydrogel with comparable properties with milk permeate (as received from a cheese processing plant) in place of reagent-grade lactose.

Inventor: Marc Hillmyer

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Simplified Recycling of Multicomponent Polymer Products

This technology is a new multiblock copolymer compatibilizer that improves the recyclability of mixed plastic waste streams such as PET-PE (poly(ethylene terephthalate) – polyethylene). New methods are used to synthesize novel PET-PE multiblock copolymers that exhibit compatibility and mechanical strength in polyester/polyolefin multilayer films and blends. The method couples oligomers of poly(ethylene terephthalate) (PET) and polyethylene (PE). The materials enable recyclabilty of PET/PE products as blends. In addition, the new multiblock copolymer can be used as a tie-layer adhesive between polyolefin and polyester layers of a multilayer film.

Inventor: Christopher Ellison, Kevin Miller

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Sustainable Triblock Copolymers as Strong, Tunable, and Degradable Pressure Sensitive Adhesives

Researchers at the University of Minnesota have developed a new method to prepare novel PSA materials from renewable resources with high bio-based contents (>90%). Specifically, a series of ABA triblock copolymers were designed and successfully synthesized with corn-derived poly(lactide) (PLA) as the glassy end blocks and poly(pentadecyl caprolactone) (PPDCL) containing a long alkyl (C15) substituent as the rubbery B-central block. This PPDCL is a new aliphatic polyester that was synthesized from cashewnut-shell-liquid-derived lactones in a controlled and tunable fashion. The new PSA material exhibits adhesion properties competitive with commercial adhesives (such as duct tape) with the added benefit of renewable bio-based contents and hydrolytic degradability.

Inventors: Christopher Ellison, Marc Hillmyer

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Process to Manufacture Branched Caprolactone

A cost effective, new two-stage chemical process manufactures methyl-ε-caprolactone (MCL) from cresol, a fossil or bio-renewable feedstock. Details for designing a process optimized for net present value (including unit operation design of two reactors, distillation and integrated heat transfer) were determined via process simulation. The two-reaction process first hydrogenates cresol to methyl-cyclohexanone, which is then followed by Baeyer-Villiger oxidation to MCL. Improvements in overall selectivity via catalytic performance of the Baeyer-Villiger oxidation catalyst boost the overall economics of the process, rendering it a low-cost process broadly applicable to multiple classes of alkyl-phenol feedstocks. The novel process can manufacture MCL for use in polymer/plastics.

Inventors: Paul DauenhauerMarc Hillmyer

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High Yield Synthesis of Bio-based Acrylic Acid and Acrylate Monomers from Lactic Acid

A new, sustainable method synthesizes acrylic acid and acrylate esters starting from alkyl lactates. The method reacts alkyl lactate with carbon monoxide and ethylene in presence of a palladium catalyst, resulting in catalytic hydroesterification of the alkyl lactates yields alkyl 2-(propionyloxy)propanoates. Pyrolysis of the alkyl 2-(propionyloxy)propanoates yields acrylate esters and propionic acid, and further hydrolysis of the acrylate esters yields acrylic acid. The synthetic method provides quantitative yields of the 2-(propionyloxy)propanoates, making it ideal for scale-up use in industry, and the catalytic species can be generated in situ in both in the neat alkyl lactate and in organic solvent from inexpensive and readily available starting materials.

Inventor: Marc HillmyerIan Tonks

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Polyethylene/iPolypropylene Multiblock Copolymer Adhesives & Compatibilizers

Polyethylene (PE) and isotactic polypropylene (iPP) are the most abundantly produced worldwide commodity plastics, representing over 120 million metric tons of the plastic produced annually. They are inexpensive monomers but represent a challenge to recycle because of their inherent immiscibility with each other, which induces substantial sorting costs. In fact, PE and iPP have poor bonding properties due to their hydrophobic composition and can only be adhered together with energy intensive and/or expensive surface functionalization or by using PE and iPP that are produced by homogenous catalysts.

Inventor: Geoffrey CoatesAnne LaPointe, James Eagan

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Efficient Process to Make Biodegradable Polyesters and Green Solvents from Itaconic Acid

A new process synthesizes multifunctional alcohols from bio-derived carboxylic acids. Starting with itaconic acid or mesoconic acid, this high-yield, two-step process uses heterogeneous catalysts in aqueous media as an efficient method of producing of lactones, diols and triols, where resulting alcohols such as 2-methyl butanediol and 3-methyl-1,5-pentanediol can be used to prepare polyesters. The diol compounds are created by reacting itaconic acid or mesoconic acid with hydrogen (H2) gas to form a lactone  such as (alpha/beta)-methyl-gamma-butyrolactone (MGBL).  MGBL can then be reacted further with hydrogen to make 2-methyl butane diol.  MGBL also presents an interesting possibility as a renewable, green solvent.

Inventor: Kechun Zhang, Paul Dauenhauer

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Isosorbide-based Methacrylate Monomer for High Tg Polymers

A new isosorbide derivative has been synthesized which can be polymerized and incorporated into block polymers. The monomer, AMI (acetylated methacrylic isosorbide), can be efficiently synthesized in two steps from commercially available starting materials. It can be polymerized using a variety of methods including traditional free radical and Reversible Addition-Fragmentation chain Transfer (RAFT) polymerizations. The resulting polymers are isosorbide-based polymethacrylates. Additional research focusing on thermoplastic elastomer applications is on-going.

Inventor: Theresa ReinekeMarc Hillmyer

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Biorenewable Alternative to Polyacrylates

An environmentally friendly process has been developed for the synthesis of isoprenecarboxylic esters and their corresponding polymers from a fermentation product of glucose: mevalonolactone. In this method, bio-renewable mevalonate is used to synthesize mevalonolactone, which can then be converted to anhydromevalonolactone. An eliminative opening of anhydromevalonolactone using a base like tert-butoxide creates the precursor to isoprenecarboxylic esters (e.g., methyl, ethyl, n-butyl, and t-butyl derivatives) with different sizes of the ester alkyl moiety. The final step is radical polymerization of these esters or the precursor acid, using AIBN as initiator, which leads to the ultimate poly(isoprenecarboxylate) product. The varying alkyl ester moiety changes the polymer’s properties creating the possibility of polymers suited for a variety of applications.

Inventor: Thomas Hoye, Nicolas Ball-Jones, Grant Fahnhorst

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Renewable Chemicals from Furans

A new reaction path has been discovered to make metastable lactone acid in high yield (94%) by simple mixing of a 1:1 blend of corn-based chemicals – itaconic anhydride and furfuryl alcohol – at room temperature.  In addition, multiple reaction pathways have also been demonstrated for conversion of itaconic anhydride and furans into derivatives amenable to novel polymer or chemical compound synthesis. See Image Gallery for sample of possible synthesis pathways.

Inventor: Thomas Hoye

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Monomer Recovery from Biobased Polyurethane

Biobased and chemically recyclable polyurethane (PU) offers a greener alternative to petroleum derived polyols used in the synthesis of thermoplastic polyurethanes, flexible foams and elastomers. A new technique uses renewable and degradable β-methyl-δ-valerolactone (MVL), to create a bio-based PMVL (poly β-methyl-δ-valerolactone) polyol with similar mechanical properties and performance of petroleum-derived PU.

Inventor: Marc HillmyerFrank Bates, Christopher Macosko

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Environmentally Friendly Thermoset from Sugar

A process has been developed for synthesizing two new dimethacrylate monomers from glucose and mannose. The materials produced by the sugar-derived dilactones undergo degradation in basic conditions while remaining stable in neutral and acidic environments. The dimethacrylates are derived from sugars, making them renewable and comparable to petroleum-based sources. The monomers reported are sugar-derived dimethacrylates, and provide a pathway to create sustainable materials for use in coatings, thermosets, adhesives and particle-based drug delivery.

Inventor: Marc HillmyerTheresa Reineke

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Bio-based Elastomers from Recoverable Methyl Valerolactone

A novel method synthesizes low-cost, polymeric valerolactones with tunable mechanical properties and low glass transition temperatures. Chemically crosslinked poly(β-methyl-δ-valerolactone) (PMVL) elastomers are created from high molar mass PMVL homopolymers that can be chemically converted back to recover the monomer in high purity. In addition, the crosslinked PMVL materials are highly tunable and exhibit lower glass transition temperature values (near −50°C).

Inventor: Marc Hillmyer

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Biomass-Derived Isoprene in High Yield

A new process uses a novel catalyst to synthesize isoprene in high yields. Isoprene is made by contacting 3-methyltetrahydrofuran (MTHF) with a heterogeneous acid catalyst (other than alumina, or Al2O3). This catalytic process dehydrates MTHF to isoprene via several combinations of temperatures, pressures, and space velocities (reactant volumetric flow rate per volume of catalyst) and achieves conversion rates of MTHF to isoprene of up to 100%.

Inventors: Paul Dauenhauer, Kechun Zhang

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Biobased Polymer Synthesis from Sugar

A method of creating a scalable block copolymer from a new branched lactone monomer has been developed. The new lactone monomer is generated from direct fermentation of sugar.  The biobased monomer, when copolymerized with lactide, has many utilities and its mechanical properties (e.g. stretchiness, strength) can be tuned depending on the application requirements. Sugar (glucose) is one of nature’s simplest and most common organic compounds, and the resultant polymers from this new process are biodegradable, affordable, and available for mass-production. Applications of these polymers are disposable materials, thermoplastics, and sustainable plastic components.

Inventors: Frank BatesMarc Hillmyer, Kechun Zhang

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Olefin Synthesis from Biomass

A catalytic process allows commodity olefins to be synthesized from the carboxylic acids of biomass. This bio-based feedstock approach is a desirable method for generating olefins that can be used to make plastics and other chemicals. The process, which involves the decarbonylation of carboxylic acids from biomass, creates olefins such as styrene, acrylates, acrylonitrile and octene in moderate to good yield. Furthermore, by adding a tandem Heck-type coupling reaction, the process can also generate stilbenes, which are desired bioactive targets.

Inventors: Marc HillmyerWilliam Tolman

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Biosynthetic Pathway to 1,4-Butanediol and other C4-C5 Chemicals

To reduce the costs of making valuable C4-C5 renewable chemicals, a biosynthetic pathway has been developed to generate C4-C5 chemicals, such as succinate, amino acids and 1,4-butanediol. This new pathway from sugars involves only five fermentation steps, as compared to the current pathway, which requires 23 steps. The new process uses engineered microbes and a simple pathway that produces less contaminating byproducts and higher yields (50% higher theoretical yield). This new approach makes the production of cost-effective renewable bioplastics, polyesters and spandex a possibility.

Inventor: Kechun Zhang

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Stereocomplexation of Poly(propylene succinate) for the Synthesis of a Biorenewable Semicrystalline Polyesters

This invention describes a new aliphatic polyester stereocomplex formed from the mixture of racemic, isotactic, regioregular chains of poly(propylene succinate). The resulting material has a characteristic melting point approaching that of low density polyethylene.

Inventors: Geoffrey Coates

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Porous Cyclodextrin Polymer for Rapid Removal of Organic Contaminants in Water Purification

The invention provides alternative broad-spectrum sorbents for water
purification and other applications with superior adsorption kinetics.

Inventor: William Dichtel

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The following companies were founded by CSP researchers and based on CSP research innovations.


“CycloPure has developed the first ever porous cycodextrin polymers with selective adsorption against unwanted compounds. We rapidly remove selective pollutants present in low concentration, sustainably and cost-effectively. CycloPure provides pioneering adsorption technologies to protect human health and the environment. ” — CycloPure

Founder: William Dichtel

CycloPure Website

Valerian Materials

“Valerian Materials will lead the way in renewable, degradable, and recyclable polymers. The biomass derived materials have applications as resilient foams and elastomers as well as tough plastics and thermosets. The principal technology relies on efficient and economical fermentation of sugar to give small molecules that can be catalytically converted to polymers in high yields at low temperatures with controlled molar mass. The versatility of the polymer platform is a key aspect and allows for broad penetration in a wide variety of industries. ” — Valerian Materials

Cofounders: Kechun ZhangFrank Bates, Marc Hillmyer

Valerian Materials Website