摘要:
A thermoplastic polymer having good tensile strength at elevated temperatures is obtained by modifying a block copolymer composed of a conjugated diene compound and an alkenyl arene compound. The block copolymer is first selectively hydrogenated and thereafter modified by grafting silicon or boron containing functional groups primarily in the alkenyl arene block via metalation. Each silicon containing functional group preferably contains at least two functional groups which allow crosslinking by condensation reactions.
摘要:
A process for preparing a coupled asymmetric block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene which comprises:(a) adding sufficient anionic polymerization initiator to the vinyl aromatic hydrocarbon monomer to start polymerization of the vinyl aromatic hydrocarbon,(b) polymerizing the vinyl aromatic hydrocarbon for a time sufficient to form a first set of vinyl aromatic hydrocarbon blocks having a desired molecular weight,(c) adding sufficient anionic polymerization initiator to start polymerization of a second set of vinyl aromatic hydrocarbon blocks,(d) completing the polymerization of the vinyl aromatic hydrocarbon for a time such that the first set of vinyl aromatic hydrocarbon blocks continues to grow to the desired molecular weight and the second set of vinyl aromatic hydrocarbon blocks grows to a desired smaller molecular weight,(e) adding a conjugated diene and polymerizing it on the ends of the vinyl aromatic hydrocarbon blocks for a time sufficient to form vinyl aromatic hydrocarbon-conjugated diene arms of the desired molecular weight, and(f) adding a coupling agent and coupling the arms to form the asymmetric block copolymer.
摘要:
A low viscosity low temperature hot melt adhesive which contains a predominantly branched styrene-isoprene-styrene block copolymer composition comprised of linear polymeric blocks wherein the polystyrene block molecular weight is greater than about 12,000, the polystyrene content is about 35% or less by weight of the block copolymer composition and the molecular weight of the block copolymer composition and the coupling efficiency are chosen so that the melt viscosity of the adhesive made with the composition is less than about 3100 cps.
摘要:
A sealant composition comprising:(a) 100 parts by weight of a silane functionalized polymer component which is prepared by reacting enough silane of the general formula R R'.sub.n SiY.sub.3-n (where n equals 0, 1 or 2 and where R is a non-hydrolyzable organic group which is capable of grafting onto the polymer, R' is a non-hydrolyzable organic group incapable of grafting onto the polymer and Y is a hydrolyzable organic group) with a polymer component to thereby functionalize the polymer component and provide a resultant sealant composition with adhesion which is resistant to deterioration in the presence of water;said polymer component comprising an A'B' block copolymer, a multiblock copolymer having at least two end blocks A and at least one midblock B, or mixtures of an A'B' block copolymer and the multiblock copolymer wherein:the A' and A blocks comprise monoalkenyl arene blocks and the B' and B blocks comprise substantially completely hydrogenated conjugated diene polymer blocks, and the average molecular weight of the A and A' blocks is greater than the minimum molecular weight needed to obtain microphase separation and domain formation of the A and A' blocks, and is less than the maximum molecular weight which would render the polymer incapable of being melt processed;the multiblock copolymer comprises a monoalkenyl arene content no more than a maximum weight percent needed to retain a modulus suitable as a sealant for the resultant composition and no less than a minimum weight percent needed to obtain the desired phase separation and the desired minimum cohesive strength for the resultant composition;(b) an amount of a midblock compatible component wherein said midblock compatible component is at a concentration to maintain the resultant composition in a plyable condition at room temperture and to maintain the glass transition temperature of the resultant composition below 10.degree. C.
摘要:
Oiled SIS polymers and processes for their production are disclosed. These processes result in advantages including reduced mixing time and less shear degradation. An adhesive composition comprising the oiled polymer of the invention is also disclosed.
摘要:
Thermoplastic polyurethanes are formed from a hydrogenated polydiene diol having from 1.6 to 2 terminal hydroxyl groups per molecule and a number average molecular weight between 500 and 20,000, an isocyanate having two isocyanate groups per molecule, and optionally a chain extender having two hydroxyl groups per molecule. The thermoplastic polyurethanes have excellent resistance to moisture as evidenced by retention of more than 70%, preferably at least 85%, of original tensile strength after aging in water for 7 days at a temperature of at least 70.degree. C. Preparation by a prepolymer method with subsequent addition of the chain extender is preferred.
摘要:
The present invention provides a method for making a method for making high service temperature rubber compound, hot melt adhesive or sealant compositions by combining a polyphenylene ether resin with an elastomeric block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene, which comprises (a) making a masterbatch of 2 to 50 phr of a polyphenylene ether having an intrinsic viscosity of 0.3 deciliters per gram or more and 100 phr of said block copolymer by extruding them together with 2 to 30 phr of an endblock compatible resin, and (b) optionally mixing the masterbatch with more of the block copolymer.
摘要:
An adhesive which contains a tackifying resin and a branched three-armed block copolymer composition comprised of polymeric blocks wherein the molecular weight is from about 180,000 to about 250,000, the polystyrene content is from about 17 to about 23% by weight of the block copolymer composition and the percentage of S-I arms which are load bearing is greater than about 85%.
摘要:
A sealant composition comprises a functionalized polymer component which is prepared by grafting enough carboxylic acid, dicarboxylic acid, or derivative thereof onto a polymer component to thereby functionalize the polymer component and provide a resultant sealant composition with adhesive which is resistant to deterioration in the presence of water, said polymer component comprising a multiblock copolymer having at least two end blocks A and at least one midblock B, wherein the A blocks comprise monoalkenyl arene blocks and the B blocks comprise substantially completely hydrogenated conjugated diene polymer blocks.