摘要:
A process for halogenating polymers by contacting a polymer either in solution or in bulk with a halogenating agent in the presence of an acid scavenger. Halogenated polymer, e.g., butyl rubber, with a particular structure is obtained and the product suffers less molecular weight loss. Combinations of acid scavengers can also be used and the scavenger can be dispersed in the polymer prior to halogenation and/or added to the reaction zone during halogenation.
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.
摘要:
A halogenation process is provided for halogenating a polymer, in which process the halogenation reaction product is neutralized by reaction of an aqueous alkaline material in the presence of a critical limited amount of alcohol to increase the neutralization rate.
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.
摘要:
This invention provides for curable and graft-cured polymer compositions prepared from a mixture comprising:a) an elastomeric copolymer containing from about 0.01 up to about 10 mole % of Y ester groups randomly distributed along and pendant to the elastomeric polymer chain, said Y ester groups having the structure: ##STR1## wherein R.sub.2 and R.sub.3 are independently selected from the group consisting of hydrogen and an alkyl group containing 1 to about 6 carbon atoms and R.sub.4 is selected from the group consisting of hydrogen, an alkyl group containing from 1 to about 28 carbon atoms, an aryl group and an alkenyl group containing from 2 to about 28 carbon atoms; andb) at least one free radically polymerizable monomer. The invention also provides for a process for preparing graft-cured polymer compositions comprising forming the above recited mixture of (a) and (b) and subjecting said mixture to free radical polymerization conditions. The Y ester groups pendant to the elastomeric polymer chain, e.g. benzylic(meth)acrylic acid ester groups present in isobutylene/para-methystyrene interpolymer chains, are capable of participating in free radical initiated reactions with monofunctional or polyfunctional free radically polymerizable monomers to produce graft-crosslinked compositions having an unusual balance of physical properties. These compositions may be formed into shaped articles such as films, coatings, adhesive layers and moldings and subjected to free radical polymerization conditions to produce crosslinked shaped articles.
摘要:
Methods for preparing reinforced molding compounds are disclosed, comprising preparing a first paste component from a mixture of a thermosetting unsaturated polyester component, a free radical polymerizable monomer component and an inorganic particulate filler component, preparing a second paste component from a conjugated diene butyl elastomer copolymer component, a free radical polymerizable monomer component, and an inorganic particulate filler component, and combining the first and second paste components in order to produce an elastomer modified thermosetting unsaturated polyester molding compound having improved surface appearance, toughness and impact strength. Preferably, one or both of the paste components will include a thermoplastic polymer additive component to provide low profile qualities to the product.
摘要:
An improved promoted curing system for halogenated elastomers has been discovered wherein the curing system contains one or a mixture of bismuth carboxylates having the structure of Formula 1: ##STR1## wherein R.sub.1 is selected from the group consisting of straight or branched chain alkyl groups having from 4 to about 30 carbon atoms, aromatic groups containing 6 to about 30 carbon atoms and alkaryl groups containing from 7 to about 30 carbon atoms.It has been found that the use of these bismuth salts, alone or in combination with zinc compounds in the cure of compositions containing halogenated elastomers leads to full, low reversion cures and curable compositions exhibiting very low precure scorch properties.
摘要:
A process is provided for vulcanizing a halogen-containing copolymer of a C.sub.4 to C.sub.7 isomonoolefin and a para-alkylstyrene utilizing a vulcanization mixture comprising a basic zinc carbonate hydroxide.
摘要:
A process for preparing a brominated butyl rubber high in Primary Allylic Bromine which comprises reacting the rubber in solution with elemental bromine at a temperature of about 65.degree. C. to about 130.degree. C. The process is preferably carried out under substantially anhydrous conditions.
摘要:
A partially crosslinked, unsaturated elastomeric polymer of a C.sub.4 to C.sub.7 isomonoolefin and a C.sub.4 to C.sub.14 conjugated multiolefin is provided which has a low crosslink density. The partially crosslinked polymer is produced by curing an uncrosslinked unsaturated polymer having a low level of chemically bound halogen with a curing agent which reacts only with the halogen. Processes for preparing these partially crosslinked unsaturated polymers are also provided.