摘要:
The synthesis and characterization of star copolymers by living carbocationic copolymerization of statistical polymers comprising monomers of isobutylene (IB) and another monomer selected from the group consisting of styrene, isoprene and living carbocationically copolymerizable derivatives thereof is described. The poly(isobutylene-co-styrene) arms emanate from a calix[n]arene core where n preferably equals 8, forming an multi(octa)-arm star. The arms are advantageously fitted with crosslinkable termini such as allyl or hydroxyl end groups. The hydroxyl-terminated arm star copolymers are particularly suitable for use in coatings when reacted with crosslinking agents such as isocyanates.
摘要:
A multipurpose hot melt adhesive comprising endblock resin in combination with a radial or linear SBS copolymer having a solution viscosity greater than 1000 cPs at 25% in toluene suitable for use as both a construction and elastic attachment adhesive in disposable products is disclosed.
摘要:
A polymerizable composition suitable for storage prior to polymerization is made by mixing a phthalonitrile monomer and a curing agent under non-reactive conditions below the melting temperatures of the phthalonitrile monomer and the curing agent and in the absence of a solvent to create a homogeneous, unreacted mixture.
摘要:
Composition of vinylarene/hydrogenated diene block copolymers, the latter being selected from ethylene-butene and ethylene-propylene, characterized in that it comprises: a) copolymers having linear structures from 30% to 60% by weight, preferably from 35% to 50%; b) copolymers having branched structures from 70% to 40% by weight, preferably from 65% to 50%; the sum of components (a) and (b) being equal to 100; the weight average molecular weight of the above composition ranging from 30,000 to 400,000, preferably from 50,000 to 200,000.
摘要:
Novel hot melt construction adhesives for disposable articles, such as diapers, sanitary napkins, medical gowns, surgical drapes, and the like, are described which offer superior properties versus currently available hot melt adhesives. These hot melt construction adhesive compositions comprise a blend of styrene-isoprene block copolymer containing at least about 25 weight percent styrene and styrene-butadiene block copolymer containing at least about 25 weight percent styrene, at least one compatible tackifying resin and at least one plasticizer. The hot melt construction adhesive possesses a viscosity no greater than about 25,000 mPa·s at about 140° C., a shear adhesion failure temperature of at least about 60° C., and a static shear time to failure of no less than about 25 hours at about 23°.
摘要:
An object of the present invention is to provide a block copolymer having the excellent improving characteristics. Specifically, the block copolymer is a hydrogenated block copolymer capable of obtaining a molded product, as a polyolefin based resin composition, having excellent physical property balance between impact resistance, in particular, low temperature impact resistance and rigidity, and molding processability, and further, capable of providing, as a viscous adhesive composition, a composition having an excellent balance between adhesion characteristics such as adhesive power and retentivity, and having excellent melt viscosity stability under heating at a high temperature. The block copolymer is a hydrogenation product of a block copolymer having at least one polymer block mainly comprising a vinyl aromatic hydrocarbon and at least one polymer block mainly comprising a conjugate diene compound, and having a vinyl bonding amount V (%) based on the conjugate diene compound of from not less than 37% to less than 70%, wherein (a) the total hydrogenation ratio H (%) of the unsaturated double bond based on the conjugate diene compound satisfies the following relational formulae: V
摘要:
A soft gelatinous elastomer composition and article useful as fishing bait formed from one or a mixture of two or more of a hydrogenated styrene isoprene/butadiene block copolymer(s) and one or more plasticizers being in sufficient amounts to achieve a gel rigidity of from about 20 gram Bloom to about 1,800 gram Bloom.
摘要:
There is provided a composition comprising a unique polymeric compound that provides a soft, flexible product. There is also provided a unique polymeric tampon applicator that is soft and flexible. When used as a tampon applicator barrel, the barrel is more comfortable and has improved ease of insertion. The polymeric compound primarily comprises a thermoplastic resin and a block copolymer that exhibit unique load, energy and modulus of elasticity properties. The polymeric compound should also include a plasticizer and a compatibilizer/flow modifier, and may include a slip/mold release agent, an antioxidant, and even a pigment. There is also provided a method for making the polymeric compound that will be formed into a product, such as an applicator or applicator barrel in which all of the above ingredients, except for the thermoplastic resin, are combined and formed into soft pellets. The soft resin pellets are then dry blended with pellets of the thermoplastic resin. The mixture of the thermoplastic resin pellets and the soft resin pellets are then melted and injection molded into the desired shape. There is thus provided a method of making a soft, polymeric tampon applicator or tampon applicator barrel.
摘要:
The present invention provides high mechanical strength amphiphilic polymeric networks and implantable biological devices made therefrom that are capable of encasing and, thus, immunoisolating biological material from an immunological response of a host individual. The present invention also provides methods for making the amphiphilic networks and implantable biological devices. The present invention also provides a method for the treatment of type I diabetes mellitus comprising the steps of encasing a sufficient amount of islet of Langerhans cells within said biological device, wherein said biological device is capable of immunoisolating said encased islet cells upon implantation into an individual; implanting said biological device into a diabetic host individual; allowing said implanted biological device to remain implanted in said diabetic individual for a time sufficient to normalize the blood glucose level in said diabetic individual.
摘要:
Compositions have been created comprising a blend of a polypropylene having less than 90 percent isotactic linkages and thermoplastic block copolymers. Specifically, the thermoplastic block copolymers comprise hard segments of polystyrene combined with soft segments comprising 2 to 8 carbon atoms. Some of the physical characteristics of materials made by these composition are more desirable than the same physical characteristics of materials made of the polypropylene having less than 90 percent isotactic linkages used to make the composition and of the same physical characteristics of materials made of the thermoplastic block copolymer used to make the composition.