摘要:
A method of oxidizing the surface of carbon microfibers that includes contacting the microfibers with an oxidizing agent that includes sulfuric acid and potassium chlorate under reaction conditions sufficient to oxidize the surface. The invention also features a method of decreasing the length of carbon microfibers that includes contacting the microfibers with an oxidizing agent under reaction conditions sufficient to decrease the length.
摘要:
The present invention is a novel block copolymer containing a controlled distribution copolymer block of a conjugated diene and a mono alkenyl arene, where the controlled distribution copolymer block has terminal regions that are rich in conjugated diene units and a center region that is rich in mono alkenyl arene units. Also disclosed is a method for manufacture of the block copolymer.
摘要:
A method of oxidizing the surface of carbon microfibers that includes contacting the microfibers with an oxidizing agent that includes sulfuric acid and potassium chlorate under reaction conditions sufficient to oxidize the surface. The invention also features a method of decreasing the length of carbon microfibers that includes contacting the microfibers with an oxidizing agent under reaction conditions sufficient to decrease the length.
摘要:
The anionic polymerization of unsaturated monomers with functionalized initiators having the structure R.sup.1 R.sup.2 R.sup.3 Si--O--A'--Li is improved by selecting A' from the structures --CH.sub.2 --CH.sub.2 --CH.sub.2 -- (1,3-propyl), --CH.sub.2 --CH(CH.sub.3)--CH.sub.2 -- (2-methyl-1,3-propyl), --CH.sub.2 --C(CH.sub.3).sub.2 --CH.sub.2 --(2,2-dimethyl-1,3-propyl), or --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --(1,8-octyl). This narrow class of polymerization initiators operate at surprisingly higher polymerization temperatures with surprisingly lower amounts of dead initiator than similar initiators wherein A' is --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --(1,4-butyl), --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --(1,5-pentyl), or --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --(1,6-hexyl).
摘要:
The capping of anionic polymers to make functionalized polymers is used to make heterotelechelic polymers by using a protected functional initiator to polymerize a polymer comprising a conjugated diene and then capping the polymer with low surface energy fluorocarbons. The protected functional groups are stable under a variety of conditions and then readily convert to more reactive terminal functional groups useful for making sealants, coatings, molded or extruded goods and fibers having low surface energy.
摘要:
Living anionic polymers of unsaturated monomers are conveniently capped with oxetane or an alkyl substituted oxetane to provide terminal primary hydroxyl groups. The hydroxyl capped polymers are useful in making coatings, sealants, binders, and block copolymers with polyesters, polyamides, and polycarbonates.
摘要:
The anionic polymerization of unsaturated monomers with functionalized initiators having the structure R.sup.1 R.sup.2 R.sup.3 Si--O--A'--Li is improved when each R is methyl and A' is --CH.sub.2 --C.sub.6 H.sub.10 --CH.sub.2 -- or --CH.sub.2 --CR'R"--CH.sub.2 -- wherein R' is a linear alkyl having from 1 to 10 carbon atoms and R" is hydrogen or a linear alkyl having from 1 to 10 carbon atoms. This initiator provides process and product advantages over all other known initiators of the same type.
摘要:
A process for making polymers of conjugated dienes which contain hydroxyl groups in the diene blocks which comprises(a) making a precursor polymer by polymerizing at least one conjugated diene which leaves 1,2 disubstituted, 1,1 disubstituted, 1,1,2 trisubstituted or tetrasubstituted olefinic unsaturation in the polymer,(b) optionally partially hydrogenating said precursor polymer,(c) epoxidizing said precursor polymer such that epoxy groups form at said substituted sites and the amount of epoxy functionality in the polymer is from 0.1 to 5 Meq/g polymer, and(d) reacting the epoxidized polymer with an alcohol solution of hydrochloric acid.A diene polymer containing 0.1 to 10 Meq/g polymer of hydroxyl group and comprised of alcohol units of the formula ##STR1## where R.sub.1 and R.sub.2 are hydrogen or alkyl radicals and X and X' are either --OH or --Cl and at least one of them is --OH.
摘要:
The present invention relates to novel compositions comprising (a) anionic block copolymers of mono alkenyl arenes and conjugated dienes where one of the blocks is a controlled distribution copolymer of a conjugated diene and mono alkenyl arene having a specific arrangement of the monomers in the copolymer block, and (b) tailored softening modifiers have a particular structure that results in a surprising improvement in properties for the composition. Also included are processes for the manufacturing such novel compositions and various end-uses and applications for such compositions.
摘要:
A method of oxidizing the surface of carbon microfibers that includes contacting the microfibers with an oxidizing agent that includes sulfuric acid and potassiaum chlorate under reaction conditions sufficient to oxidize the surface. The invention also features a method of decreasing the length of carbon microfibers that includes contacting the microfibers with an oxidizing agent under reaction conditions sufficient to decrease the length.