Abstract:
High Mooney viscosity elastomers having low volatiles content, and processes for producing such elastomers, are provided herein. In particular aspects, the elastomers are metallocene-catalyzed elastomers, such as mEPDM elastomers. Processes for producing such elastomers include devolatilization of an elastomer stream comprising such elastomers, using a kneader. The kneader is counterintuitively operated such that the internal agitating paddles rotate at relatively low speeds. It is believed these low speeds help maintain the elastomer stream as a toffee-like composition, preventing the elastomer stream within the kneader from becoming a crumbly composition, which is difficult to devolatilize.
Abstract:
Brominated styrene-butadiene copolymers are recovered from solution in an organic solvent. The copolymer solution is mixed with a liquid non-solvent in the presence of a suspension stabilizer to form a dispersion. The dispersion is heated to vaporize the organic solvent. This process produces precipitated copolymer particles having useful particle sizes, which can be easily used in downstream applications.
Abstract:
Provided herein are organic solvent-based processes for the removal of rubber from aged briquettes made from compressed plant matter (briquettes) of non-Hevea plants. Also provided are aged briquettes made from the compressed plant matter of non-Hevea plants where the briquettes have been aged for either various time period after formation and the rubber within the briquette has retained its a molecular weight to within a specified range.
Abstract:
Disclosed is a method and apparatus for the extraction of high molecular weight biopolymers from plants. Specifically, the invention described herein relates to the commercial processing of plant material, including that from desert plants native to the southwestern United States and Mexico, such as the guayule plant (Parthenium argentatum), for the extraction of biopolymers, including natural rubbers. More specifically, the invention relates to laboratory or commercial scale extraction of high molecular weight biopolymers from plant materials including the chemical and mechanical processing of the plants and purification of the extracted biopolymer.
Abstract:
Die vorliegende Erfindung betrifft ein Verfahren zur Abtrennung eines Polymers aus einer Polymerlösung oder -dispersion, wobei (i) eine Lösung oder Dispersion eines Polymers in einem organischen Lösungsmittel durch in Kontakt bringen mit Wasserdampf in einem Zerstäuberbehälter zerstäubt wird, (ii) das im Zerstäuberbehälter erhaltene Gemisch in einen Polymerentgasungsbehälter weitergeleitet wird und diesen durchströmt, wobei das in den Polymerpartikeln vorliegende organische Lösungsmittel durch den thermischen Kontakt zwischen den Polymerpartikeln und dem Wasserdampf zumindest teilweise aus den Polymerpartikeln ausgetrieben und in die Gasphase überführt wird, (iii) das den Polymerentgasungsbehälter verlassende Gemisch in einen Phasenseparator 1 weitergeleitet wird und das in der Gasphase vorliegende organische Lösungsmittel von den Polymerpartikeln und dem kondensierten Wasserdampf getrennt wird, (iv) die Polymerpartikel und der kondensierte Wasserdampf in einen Phasenseparator 2 weitergeleitet werden, um die Polymerpartikel von dem kondensierten Wasserdampf abzutrennen.
Abstract:
A method of making a polymer with stable Mooney viscosity and molecular weight is described. A conjugated diolefin is reacted in a hydrocarbon solvent in the presence of an initiator to form a polymer. After forming the polymer, alkoxy silane terminal functionalizing groups are bonded to the polymer. A stabilizing agent having the formula (R)4-nSi(OH)n wherein R is a C1 to C18 alkyl, C1 to C18 alkyl group containing a heteroatom such as nitrogen or oxygen, C4 to C8 cycloalkyl, or C6 to C18 aromatic group is then added to the polymer, optionally in the presence of hydrocarbon oil. The polymer is then desolvatizing, resulting in a polymer with stable Mooney viscosity and molecular weight, even over prolonged periods of time. Compositions and articles containing the polymer are also described.
Abstract:
Systems and methods for managing the waste associated with the extraction of rubber from guayule shrubs are provided. Also provided is a portable local sub-station for reducing the transportation costs associated with the processing of guayule shrubs for the extraction of rubber. Use of the disclosed systems, methods and/or local sub-station can reduce transportation costs, reduce processing costs and reduce the downstream processing complexity associated with the extraction of rubber from guayule shrubs.