Monsanto Company

A John Solodar

Mark D Paster

William D McGhee

Kenneth W Ruettimann

Fred E Strauser

Devdatt L Kurdikar

Dennis Patrick Riley

Jawed Asrar

Thomas E Waldman

Polyhydroxyalkanoate (PHA) polyester is extracted from biomass by dissolving the PHA in a non-halogenated solvent which comprises a PHA-poor solvent that dissolves less than 1% of the PHA at temperatures less than the solvent boiling point, or a mixture of a PHA-poor solvent and a PHA-good solvent. Following extraction of PHA under pressure at a temperature above about 80.degree. C., typically above the boiling point of the PHA-poor solvent, PHA polymer is precipitated by cooling the PHA-enriched solvent mixture. Suitable PHA-poor solvents can include linear and branched R.sub.1 --OH alcohols and R.sub.2 --COOR.sub.3 esters where R.sub.1 =C.sub.1 -C.sub.4, R.sub.2 =H, C.sub.1,C.sub.2, or C.sub.3, and R.sub.3 =C.sub.1 -C.sub.5.

High temperature PHA extraction using PHA-poor solvents

Polyhydroxyalkanoate (PHA) polyester is extracted from biomass by dissolving the PHA in a non-halogenated solvent which comprises a PHA-good solvent or a mixture thereof. Suitable PHA-good solvents can be selected from the disclosed alcohols, esters, amides and ketones. The PHA can be recovered, for example, by cooling, by solvent evaporation, or by addition of a PHA-poor solvent, wherein the PHA-poor solvent preferably dissolves less than about 1% (w/v) of the PHA at a temperature below the solvent boiling point. Preferred PHA types for use in the invention are poly (hydroxybutyrate-co-hydroxyvalerate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), and polymers/copolymers of hydroxyterminated polyhydroxybutyrate.

Methods of PHA extraction and recovery using non-halogenated solvents

The present invention is the novel synthesis of sterically hindered penta-substituted guanidines by a process in which (1a) an isocyanate is reacted first with a di-substituted amine or (1b) a urea is reacted with two moles of a mono-substituted amine to form a tri-substituted urea followed by (2) treatment of the tri-substituted urea with an activating agent before reacting with a second di-substituted amine in the presence of a base.

Synthesis of penta-substituted guanidines

A process for preparing isocyanates comprising contacting carbon dioxide and a primary amine in the presence of an aprotic organic solvent and a base selected from the group consisting of a phosphazene compound, an organic, nitrogenous base and mixtures thereof, wherein the organic, nitrogenous base selected from the group consisting of guanidine compounds, amidine compounds, tertiary amines and mixtures thereof to produce the corresponding ammonium carbamate salt, reacting the ammonium carbamate salt with an anhydride dehydrating agent to produce a product stream comprising the corresponding isocyanate, the aprotic organic solvent and the base salt derived from the anhydride, separating the base salt from the product stream, recovering and recycling the base, and regenerating and recycling the anhydride dehydrating agent.

Process for preparing isocyanates

A process for the preparation of substituted aromatic amines comprising (1) contacting a primary aromatic amine with an oxidizing agent in a homogeneous solution containing water, an oxidizable water-miscible organic solvent and a base, and (2) reducing the solution with a reducing agent to produce the substituted aromatic amine.

Preparation of substituted aromatic amines

Differential esterification or hydrolysis is utilized to effect separations of isomeric acids or esters.

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University City, MO, United States of America

A John Solodar