摘要:
Dehydrohalogenation of halogenated butyl to produce a butyl rubber having conjugated double bonds in the linear backbone. The composition is disclosed as having the predominant structure: ##EQU1## where n + 1 represent the number of isoolefin units incorporated in the butyl rubber polymer backbone, and m represents the number of conjugated diolefin units present, substantially as isolated units. The composition is prepared by contacting a solution of halogenated butyl rubber with: (1) a soluble metal carboxylate, where the metal is selected from the metals of Groups Ib, IIb, IVa and VIII of the Periodic Table; (2) a soluble carboxylic acid; and (3) an oxide or hydroxide of a metal selected from the metals of Groups Ia or IIa of the Periodic Table.
摘要:
Disclosed is a method for crosslinking elastomers containing randomly distributed sites of conjugated olefinic unsaturation of which the crosslinks are comprised of chains of free radical polymerizable monomers.
摘要:
A process for preparing latices in ionomeric form from copolymers of an isoolefin containing from 4 to 7 carbon atoms and a conjugated multiolefin containing from 4 to 14 carbon atoms, where a major portion of said conjugated multiolefin has conjugated diene unsaturation, is disclosed. The process principally comprises forming an adduct of conjugated diene butyl rubber with a dienophile capable of implanting carboxylic acid functionality on the polymer such as maleic anhydride, emulsifying the adduct thus formed, and neutralizing the resulting emulsion with a suitable base. Highly improved ionomeric latices are also disclosed, having an average particle size of less than about 1 micron, average solids contents easily adjusted from between about 5 to 70 weight percent solids, and having a pH, depending on the emulsifier used, of from 3 to 12. Films cast from these latices have an improved tensile at break of greater than about 2500 psi.
摘要:
Disclosed is a method for crosslinking elastomers containing randomly distributed sites of conjugated olefinic unsaturation of which the crosslinks are comprised of chains of free radical polymerizable monomers.
摘要:
In a process for the continuous halogenation of polymers by contacting polymer and halogenating agent in a continuous flow device in which means are provided for disengaging reaction by-products and unreacted halogenating agent from the reaction mixture, by deforming and disrupting the halogenated polymer surface and injecting an inert and/or reactive gas into the halogenated polymers immediately after reaction thereby neutralizing the product. In a preferred embodiment the process is carried out in an extruder-reactor and an optional, supplementary inert and/or reactive gas scrubbing zone is included. The process is amenable to saturated and unsaturated polymers.
摘要:
Disclosed is a method of preparing a moisture curable elastomer by reacting an elastomer containing randomly distributed sites of conjugated olefinic unsaturation with a cyclic unsaturated anhydride then blending the reaction product with a polyvalent metal compound and, optionally, a basic hydrolysis catalyst.
摘要:
Improved processes for the dehydrohalogenation of halogenated butyl rubber in order to prepare a butyl rubber having randomly distributed sites of conjugated unsaturation are disclosed. Such processes, which include the contacting of a solution of halogenated butyl rubber with a soluble metal carboxylate, a soluble carboxylic acid, and an oxide or hydroxide of a metal selected from Groups Ia and IIa of the Periodic Table, are carried out in a reaction zone which is maintained substantially free of free water vapor. Preferably, excess amounts of hydrophilic reagents are added to the reaction zone or in the alternative the reaction zone is purged with a drying gas.
摘要:
Blends of 5 to 95 wt. % conjugated diene-containing butyl rubber with 95 to 25 wt. % halobutyl or butyl rubber are capable of higher carbon black loading and have faster cure times, unusually high tensile strength and improved green strength. The blends may be cured with dienophilic compounds or sulfur-based cure packages.
摘要:
Aluminum trialkyl and aluminum dialkyl monohalide catalysts can be used to graft cationically polymerizable monomers, such as styrene, chloroprene, isobutylene, etc. to halogenated polymers with some highly reactive halogen atoms such as PVC, neoprene, chlorobutyl, etc.
摘要:
An improved halogenated butyl rubber wherein the polymer has a conjugated diene content of less than 0.25 mole % and a halogen content of at least 0.6 wt. %; at least 20 mole % of the halogen being in a primary allylic configuration.