Abstract: It is an object to provide a photoreactive hot-melt adhesive composition which exhibits high adhesive strength immediately after combination of adherends and excellent bond strength after completion of curing and provides a highly durable bonded laminate. A photoreactive hot-melt adhesive composition containing: (a) a bisphenol F epoxy resin that assumes a solid form at ordinary temperature; (b) at least one compound selected from the group consisting of a compound represented by the following formula (1), a copolymer of tetramethylene oxide and ethylene oxide and a copolymer of tetramethylene oxide and propylene oxide; and (c) a cationic photoinitiator; R1-(OR2)n—OR3??Formula (1) (In the formula, R1 and R3 independently represent any of a hydrogen atom, a glycidyl group, and a monofunctional substituted or unsubstituted hydrocarbon group having 1–8 carbon atoms; R2 represents a bifunctional, substituted or unsubstituted hydrocarbon group having 2–8 carbon atoms; and n is an integer of 2 or larger.

Abstract: A plastic is converted from an initial condition with a higher density into a foamed condition with a lower density using a blowing agent, wherein the plastic is cross-linked prior to foaming by means of a first cross-linking agent and during the foaming by means of at least one second cross-linking agent.

Abstract: A method for the production of a cross-linked support matrix that in form of a bed will permit liquid flow velocities above 5 cm/h, preferably above 50 cm/h, to pass through the bed. The method is characterized in that it comprises the steps: (a) providing a starting support matrix that has pendent unsaturated groups, and (b) subjecting said starting support matrix to electron beam or gamma-ray irradiation. The use of a cross-linked support matrix produced by a method comprising the steps of: (a) providing a starting support matrix that has pendent unsaturated groups, and (b) subjecting said starting support matrix to electron beam or gamma-ray irradiation as a support matrix in liquid chromatography, cell culturing, step-wise solid phase synthesis of organic compounds, running catalytic reactions by the use of a solid phase bound catalyst.

Abstract: A process for producing polypropylene having increased melt strength, the process comprising irradiating polypropylene which has been polymerised using a Ziegler-Natta catalyst with an electron beam having an energy of at least 5 MeV and a radiation dose of at least 10 kGray and mechanically processing the irradiated polypropylene to form long chain branches on the polypropylene molecules, whereby the polypropylene has a melt flow index (MFI) of at least 25 dg/min.

Abstract: UV curable adhesives are provided that comprise epoxidized monohydroxylated polydiene polymers, hydrogenated hydroxylated polydiene polymers, and selectively hydrogenated starblock copolymers. The adhesive formulations provide both excellent room temperature properties of tack and peel and excellent holding power at temperatures as high as 95° C.

Abstract: A golf ball having at least a core and a cover, wherein at least a portion of the ball is formed from a material resulting from the isomerization of an amount of polybutadiene in solution to create a resulting polybutadiene having an increased content of trans-polybutadiene, is disclosed. Isomerization can be accomplished by mixing a photo-sensitizer into the polybutadiene solution and exposing the resulting mixture to a radiation source such as ultraviolet radiation. Isomerization can also be accomplished thermally by mixing nitrogen dioxide into a sufficiently heated solution of polybutadiene and maintaining the mixture at an elevated temperature for a sufficient period of time to increase the trans-polybutadiene content of the polymer. The resulting polybutadiene is recovered, mixed with other additives as desired and formed into one or more portions of a golf ball.

Abstract: This invention relates to a process of preparation of components and articles of manufacture containing at least one of such components, such as tires, and the resulting prepared components and fabricated articles, by use of directed high frequency energy internally heated silica-rich rubber compositions which contain sulfur curative and a significant content of high softening point polymer, namely a polymer and/or elastomer having a melting point (Tm) and/or high glass transition temperature (Tg) above 0° C., and particularly above 30° C., and which contains a minimal, if any, carbon black reinforcement. Such directed high frequency energy heating is provided, individually, by directed radio frequency (electromagnetic) radiation and/or by directed microwave radiation.

Abstract: The objective of the present invention is to provide a production method by which a polymer of a functional group-terminated vinyl monomer can be easily and practically produced. Further, it is another object of the present invention to provide a functional group-terminated vinyl polymer which is useful as a material for the production of various functional products. The first aspect of the present invention is concerned with a production method of a functional group-terminated vinyl polymer comprising a step of synthesizing a halogen atom-terminated vinyl polymer by the radical polymerization reaction of a vinyl monomer in the presence of a halogen compound and a step of introducing a functional group to a terminus by substituting a functional group-containing group for the terminal halogen atom of said vinyl polymer.

Abstract: A process for producing polypropylene having increased melt strength, the process comprising (i) homopolymerising polypropylene or copolymerising propylene with one or more comonomers selected from ethylene and C4 to C101-olefins to produce a polypropylene homopolymer or copolymer respectively having a double bond concentration of at least 0.1 per 10,000 carbon atoms, (11) irradiating the polypropylene with an electron beam having an energy of at least 5 MeV and at radiation dose of at least 5 kGray, and (iii) melting and mechanically processing the melt of polypropylene to form long chain branches on the polypropylene molecules.

Abstract: This invention is a process for making UV curable adhesives, sealants, coatings, ink, flexible printing plates, laminating adhesives, fibers, gaskets, and related compositions, films, and thin parts, wherein an epoxidized monohydroxylated polydiene polymer comprised of at least two different diene monomers wherein at least one is a diene monomer which yields unsaturation suitable for epoxidation is used as the binder for the composition. The preferred epoxidized monohydroxylated polymers are block copolymers of isoprene and butadiene wherein a hydroxyl group is attached at one end of the polymer molecule. These polymers may be hydrogenated or unhydrogenated. The process involves mixing the above polymer or the polymer with one or more other formulating ingredients together with and insoluble photoinitiator which is preferably selected from the group consisting of triaryl sulfonium salts.

Abstract: A process for producing an epoxidized diene polymer includes: dispersing or suspending a diene polymer (C) having a ball-reduced particle size of 0.05-20 mm in a medium (A) in the presence of powder particles (B) insoluble in the medium (A), or in an aqueous medium in the presence of a phenol-based stabilizer and/or a phosphorus-based stabilizer; and epoxidizing the diene polymer (C) by an epoxidizing agent, therefore, problems associated with epoxidation performed by dissolving diene polymer in a solvent are eliminated; an economical method for epoxidizing, producing, and purifying a diene polymer (C) in a solid form is provided; and the epoxidized diene polymer having an excellent heat stability can be obtained.

Abstract: The invention includes an optical fiber coating that exhibits the characteristics of a pressure sensitive adhesive. A viscoelastic window for the coating will include at least one set of coordinates that is within Quadrants 2, 3, or 4 or the Transition Flow Region of the Chang viscoelastic of the rheological master curves or will not include at least one set of coordinates that is not within Quadrant 1 of the Chang viscoelastic of the rheological master curves.

Abstract: Irradiated, oxidized olefin polymer coupling agents for use in the manufacture of non-halogenated flame retardant-containing and filler-containing olefin polymer compositions and coupling agent-containing olefin polymer concentrates.

Abstract: The object of the invention is to provide a rubber composition or its crosslinked product used for a rubber stopper for a medicament or a rubber article for a medical treatment, suitable for radiation treatments to be carried out for the purpose of sterilizing. Accordingly, the present invention provides a rubber composition or its crosslinked product used for a rubber stopper for a medicament or a rubber article for a medical treatment, comprising an isobutylene copolymer, as a predominant component, with a density of at most 0.95, capable of being readily subjected to a radiation treatment.

Abstract: The present invention relates to a method for making a heat-resistant elastic article and a heat-resistant elastic article. The invention especially relates to a method of making elastic fibers and polymeric elastic fibers wherein the elastic fibers are capable of withstanding dyeing and heat-setting processes that typically are conducted at elevated temperatures (such as 110-230° C. and especially at greater than or equal to 130° C. for minutes). The inventive method comprises radiation crosslinking an article (or plurality of articles) under an inert or oxygen limited atmosphere (for example, in N2, argon, helium, carbon dioxide, xenon and/or a vacuum) wherein the article (or articles) comprises at least one amine stabilizer and preferably another optional stabilizer additive. More preferably, the radiation crosslinking is performed at a low temperature (−50 to 40° C.).

Abstract: Disclosed herein are radiation-curable polymers, a method of preparing radiation-curable polymers and compositions containing radiation-curable polymers. Radiation-curable polymers and compositions containing radiation-curable polymers are useful as coatings and adhesives.

Abstract: Polypropylene having improved long chain branching increased melt strength obtained by irradiating polypropylene with an electron beam having an energy of at least 5 MeV and with a radiation dose of from 5 to 100 kGray in the presence of a grafting agent, the branching index of the obtained polypropylene being lower than 0.7.

Abstract: The objective of the present invention is to provide a production method by which a polymer of a functional group-terminated vinyl monomer can be easily and practically produced. Further, it is another object of the present invention to provide a functional group-terminated vinyl polymer which is useful as a material for the production of various functional products. The first aspect of the present invention is concerned with a production method of a functional group-terminated vinyl polymer comprising a step of synthesizing a halogen atom-terminated vinyl polymer by the radical polymerization reaction of a vinyl monomer in the presence of a halogen compound and a step of introducing a functional group to a terminus by substituting a functional group-containing group for the terminal halogen atom of said vinyl polymer.

Abstract: Photoinitiators of formula (Ia) or (Ib) having chain transfer groups, wherein n is 1 or 2; PI is for example a group of formula (IIa); PI′ inter alia is a group of formula (IIIa); Ar is for example phenyl; Ar2 is inter alia phenylene; R1 and R2 are for example C1-C8alkyl, or R1 and R2 together C2-C9alkylene; M1 inter alia is —NR3R4 or —OH; M1′ is for example a group (c); R3′ is a direct bond, C1-C12alkylene, or phenylene; R3 is for example hydrogen, or C1-C12alkyl; R4 is e.g. C1-C12alkyl; A1 and A2 are for example a direct bond; CT is a chain transfer group; are useful for the preparation of macrophotoinitiators which can be employed for preparing block copolymers.

Abstract: The present invention relates to elastic articles comprising a crosslinked or crosslinkable ethylene polymer and a method for making the same. In particular, the invention relates to a shaped article (e.g. film or fiber) characterized by improved elasticity at elevated temperatures and comprising a substantially cured, irradiated, or crosslinked (or curable, irradiated or crosslinkable) homogeneously branched ethylene polymer. The improved elastic article of the present invention is particularly suitable for use in applications where good elasticity must be maintained at elevated temperatures such as, for example, personal hygiene items and disposable infection-control garments at body temperatures of about 100° F. (38° C.).

Abstract: The present invention relates to a sulfonated polymer membrane and to a process for the preparation thereof. According to the process, a polymer film is irradiated, and the irradiated polymer film is sulfonated in order to link sulfonic acid groups thereto. According to the invention, the sulfonation is continued until the total concentration of sulfonic acid groups in the membrane is 0.4-3.0 meq/g and they are homogeneously distributed in the membrane material in such a manner that their concentration in the middle of the membrane is at minimum 0.2 meq/g. With the help of the invention, it is possible by a rapid and simple process to prepare membranes the chemical and mechanical properties of which can be regulated by means of the selection of the initial film, by irradiation and by the sulfonation process.

Abstract: The present invention relates to shape deformable materials, which are capable of (1) being deformed, (2) storing an amount of shape deformation, and (3) recovering at least a portion of the shape deformation when exposed to a humid environment. The shape deformable materials can advantageously be in the form of films, fibers, filaments, strands, nonwovens, and pre-molded elements. The shape deformable materials of the present invention may be used to form products, which are both disposable and reusable. More specifically, the shape deformable materials of the present invention may be used to produce products such as disposable diapers, training pants, incontinence products, and feminine care products.

Abstract: In one aspect the invention provides an energy efficient polymerization method comprising irradiating a polymerizable composition and a photoinitiator with a source of essentially monochromatic radiation where the photoinitiator and the wavelength of the radiation source are selected such that the extinction coefficient of the photoinitiator at the peak wavelength of the source is greater than about 1000 M−1 cm−1 and such that the photoinitiator absorbs at least two percent of the actinic radiation incident on the coating. In another aspect the invention provides energy efficient methods of polymerizing polymerizable compositions and crosslinking crosslinkable compositions by irradiating the respective compositions with a low power source of essentially monochromatic radiation. The low power energy sources have an input power of less than about 10 W/cm.

Abstract: Graft copolymers with low molecular weight side chains are prepared by (1) irradiating a propylene polymer material in the absence of oxygen, (2) adding a controlled amount of oxygen to the irradiated polymer material so that the polymer is exposed to an amount of oxygen greater than 0.004% but less than 15% by volume at a temperature of 40° C. to 140° C., to produce an oxidized propylene polymer material containing greater than 1 mmol total peroxide per kilogram of propylene polymer material, (3) optionally, heating the oxidized propylene polymer material in a non-oxidizing atmosphere to a temperature of at least 80° C.

Abstract: The present invention relates to a method for making a heat-resistant elastic article and a heat-resistant elastic article. The invention especially relates to a method of making elastic fibers and polymeric elastic fibers wherein the elastic fibers are capable of withstanding dyeing and heat-setting processes that typically are conducted at elevated temperatures (such as 110-230° C. and especially at greater than or equal to 130° C. for minutes). The inventive method comprises radiation crosslinking an article (or plurality of articles) under an inert or oxygen limited atmosphere (for example, in N2, argon, helium, carbon dioxide, xenon and/or a vacuum) wherein the article (or articles) comprises at least one amine stabilizer and preferably another optional stabilizer additive. More preferably, the radiation crosslinking is performed at a low temperature (−50 to 40° C.).

Abstract: The present invention provides a fully vulcanized powdery rubber having a particle size of from 20 to 2000 nm, its preparation and use. The vulcanized powdery rubber is obtained by irradiating a rubber latex having a particle size of from 20 to 2000 nm with a high-energy irradiation. The vulcanized powdery rubber is very easily to be dispersed into various plastics, and thus can be mixed with various plastics to prepare toughened plastics and fully valcanized thermoplastic elastomers.

Abstract: A method of preparing a conjugated polymer which includes: determining a first intermolecular repeat distance and a first tilt angle relative to the translation axis for a guest molecule having a first atom and a second atom; selecting a host molecule having a second intermolecular repeat distance and a second tilt angle relative to the translation axis; synthesizing the host molecule and the guest molecule to form a co-crystal, wherein the first and the second repeat distances and the first and the second tilt angles are about equal so that when said host molecule and said guest molecule are synthesized the first atom and the second atom of adjacent guest molecules are in near van der Waals contact; and polymerizing the co-crystals to form the conjugated polymer. In a preferred embodiment, the guest molecule is a polytriacetylene and the host molecule has an intermolecular repeat distance of from about 6.0 Å to about 8.

Abstract: A process and resulting product is provided in which a vulcanized solid particulate, such as vulcanized crumb rubber, has select chemical bonds altered by biotreatment with thermophillic microorganisms selected from natural isolates from hot sulfur springs. Following the biotreatment, microwave radiation is used to further treat the surface and to treat the bulk interior of the crumb rubber. The resulting combined treatments render the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels and sizes of the treated crumb rubber can be used in new rubber mixtures and good properties obtained from the new recycled products.

Abstract: This invention relates to rubber polymers based on polymerizable monomers and having an elevated gel content together with an elevated degree of swelling, to the production of the stated rubber polymers and to the use thereof for the production of moldings of all kinds.

Abstract: The present invention relates to radiation curable compositions comprising at least one metallocene polyolefin. The radiation curable compositions are useful for a variety of applications, particularly as coatings and adhesives. The radiation curable composition may comprise a single metallocene polyolefin, or blend thereof. The ultraviolet curable compositions further comprise at least one photoinitiator and/or at least one photoinduced coupling agent. For pressure sensitive adhesive applications, the radiation curable composition also preferably comprises other ingredients such as a tackifying resins and plasticizers.

Abstract: A method and apparatus for selectively curing a sheet of ethylene-propylene diene termonomer (EPDM) material to form a roofing membrane for installation on a roof deck. The method includes the steps of providing a sheet formed of ethylene-propylene diene termonomer, the sheet having a field and longitudinal edge areas bordering the field; and then simultaneously shielding at least one edge area of the EPDM sheet and exposing at least the field to a source of radiation to cure at least the field of the EPDM sheet and provide a selectively cured EPDM roofing membrane. Also disclosed is the product formed by the method of the present invention.

Abstract: Wear resistance and oxidation resistance of polymer material or a polymer component for bioimplantation are improved by packaging a polymer object in a sealed gas impermeable package substantially free of oxygen, irradiating the package with penetrating radiation to an extent sufficient to effect a desired substantial level of cross-linking within the polymer, and warming the packaged object while maintaining an elevated hydrostatic pressure to cause gases released during irradiation to recombine, stabilizing the material against subsequent oxidative change. The pressure stabilization terminates active sites, substantially eliminating free radicals. When applied to finished parts, the process simultaneously hardens and sterilizes the parts without degrading mechanical properties or dimensions. When applied to bulk material or unfinished parts, the part may be subsequent machined or otherwise finished, and sterilized by any conventional means.

Abstract: The present invention relates to pressure-sensitive adhesive compositions. The compositions comprise a poly(1-alkene) pressure-sensitive adhesive component, a non-pressure-sensitive adhesive component, and a radiation-activatable curing agent. The invention further provides pressure-sensitive adhesive tapes and methods for making the compositions and tapes.

Abstract: Optical fiber primary coating systems are disclosed having excellent ribbon stripping and adhesion behavior. The coatings are radiation-curable. The excellent stripping and adhesion behavior can be inner primary coating composition having a slip enhancing component and a high modulus outer primary coating composition. Combination of means can be employed. Stripping behavior can be measured by crack propagation and fiber friction measurements.

Abstract: A process for decomposing a polymer which is capable of undergoing thermal depolymerization to its monomer or monomers, such as for example poly(methylmethacrylate), and for the recovery of at least one of the monomers, includes the steps of subjecting the polymer in solid, gel, partially molten or molten form to microwave heating for a time and at a temperature sufficient to decompose the polymer to produce the monomer or monomers in gaseous, liquid or solid form, without substantial decomposition of the monomer or monomers, and recovering at least one of the monomer or monomers. The monomer or monomers may then be reused for plymerisation.

Abstract: The present invention generally relates to polymeric compositions capable of providing enhanced crosslinking efficiency, to single and multilayer films having the subject composition contained within at least one layer of said film, to a method of treating said film to provide enhanced crosslink within said at least one layer of the film and to the resultant cross-linked film product as well as articles made from said cross-linked film product.

Abstract: The subject invention provides a thermoset elastomer comprising a crosslinked pseudorandom or substantially random interpolymer of: (a) from 15 to 70 weight percent of at least one .alpha.-olefin, (b) from 30 to 70 weight percent of at least one vinylidene aromatic compound, and (c) from 0 to 15 weight percent of at least one diene. The subject invention further provides a thermoplastic vulcanizate comprising the thermoset elastomers of the invention as provided in a thermoplastic polyolefin matrix. The subject invention further provides processes for preparing the inventive thermoset elastomers and thermoplastic vulcanizates, as well as parts fabricated therefrom. The inventive materials have a superior balance of properties, as compared to EPM and EPDM based materials. The subject invention also pertains to foams and methods for their preparation.

Abstract: A method for irradiating and modifying high molecular weight organic polymers with high energy radiation so that the radiation impinges only in a distinct pattern which is less than the width of the polymer so as to cause controlled chain scission and continuity in molecular weight distribution. The method improves the flow rate and millability of the polymers.

Abstract: Polypropylene mixtures of increased stress-crack resistance and melt strength can be produced by irradiating polypropylene powders with low average particle diameters by low energy electron-beam accelerators with energies of 150 to 300 keV. The polypropylene mixtures produced are suitable particularly for producing films, sheets, panels, coatings, pipes, hollow objects and foamed materials.

Abstract: A plate-shaped rubber member consists of at least one rubber mixture. The rubber member has a surface with markings and includes a pre-crosslinked layer directly below the surface at least in the area of the markings. The pre-crosslinked layer is generated by exposure of the surface of the rubber member to electromagnetic radiation or electron beam radiation.

Abstract: A graft copolymer of a propylene polymer material is prepared by (1) making an oxidized propylene polymer material by (a) irradiating a porous particulate propylene polymer material in the substantial absence of oxygen, (b) exposing the irradiated propylene polymer material to a controlled amount of oxygen of greater than 0.004% but less than 15% by volume at a temperature of 40.degree. C. to 110.degree. C., and (c) heating the irradiated polymer material to a temperature of at least 110.degree. C. in the presence of a controlled amount of oxygen within the same range as is used in the previous step, (2) dispersing the resulting oxidized propylene polymer material in water in the presence of a surfactant at a temperature of 30.degree. C.-90.degree. C., (3) adding (a) a primary reducing agent, (b) a chelating agent, and (c) a secondary reducing agent, (4) adding at least one vinyl monomer, and (5) recovering the graft copolymer from the reaction mixture.

Abstract: This invention provides novel methods for the formation of biocompatible membranes around biological materials using photopolymerization of water soluble molecules. The membranes can be used as a covering to encapsulate biological materials or biomedical devices, as a "glue" to cause more than one biological substance to adhere together, or as carriers for biologically active species. Several methods for forming these membranes are provided. Each of these methods utilizes a polymerization system containing water-soluble macromers, species which are at once polymers and macromolecules capable of further polymerization. The macromers are polymerized using a photoinitiator (such as a dye), optionally a cocatalyst, optionally an accelerator, and radiation in the form of visible or long wavelength UV light. The reaction occurs either by suspension polymerization or by interfacial polymerization.

Abstract: A method of improving heat-seals for polyolefin polymers which are coated onto a paperboard substrate. The method obviates the need for use of a curable bonding agent. The materials are exposed to high energy radiation prior to formation of the heat seal to induce crosslinking of the poller and thereby increase the average molecular weight of same.

Abstract: Only an outer surface of an unvulcanized rubber sheet is preliminarily crosslinked by irradiating an infrared ray or a far infrared ray to the unvulcanized rubber sheet prior to subsequent final vulcanization, whereby the occurrence of rubber spew and rubber flash is considerably suppressed at the vulcanization step.

Abstract: Diene modified polymers are provided as well as methods for preparing the same. The polymers have from 3-8 carbon atoms, from about 0.00005 to about 5 mole percent diene based on the total weight of the polymer. The polymers are essentially gel-free and exhibit enhanced melt strength and shear thinning behavior.

Abstract: Disclosed are graft copolymers of polyolefins and a method of preparing the graft copolymers. The method includes irradiating a mass of olefin polymer particles and thereafter treating the mass of particles with a vinyl monomer in liquid form. A nonoxidizing environment is maintained throughout the process while free radicals produced in the olefin polymer by the irradiation are present, thereby preventing degradation of the polymer. In a final step, residual free radicals are deactivated, and any unreacted monomer is removed.

Abstract: A laminating adhesive comprising an adhesive composition which comprises(a) An epoxidized block copolymer of the formula(A--B--A.sub.p).sub.n --Y.sub.r --(A.sub.q --B).sub.mwherein Y is a coupling agent or coupling monomers, andwherein A and B are polymer blocks which may be homopolymer blocks of conjugated diolefin monomers, copolymer blocks of conjugated diolefin monomers or copolymer blocks of conjugated diolefin monomers and monoalkenyl aromatic hydrocarbon monomers, andwherein the A blocks have a higher number of aliphatic double bonds between a tertiary carbon atom and either a primary, secondary, or tertiary carbon atom per unit of block mass than do the B blocks, andwherein the A blocks have a molecular weight from about 100 to about 3000 and the B blocks have a molecular weight from about 1000 to about 15,000, andwherein p and q are 0 or 1 and n>0, r is 0 or 1, m.gtoreq.

Abstract: A high molecular weight compound having a number average molecular weight of 5,000 to 30,000 formed from a styrenic or acrylic monomer chain and a rubber chain which are attached as block or graft polymers. A photopolymerizable resin composition includes a copolymer having a number average molecular weight of 5,000 to 30,000. The copolymer has a styrenic or acrylic monomer chain and a rubber chain attached in block or graft form.

Abstract: Disclosed is a normally solid, high molecular weight, non-linear, substantially gel-free, propylene polymer material characterized by high melt strength due to strain hardening which is believed to be caused by free-end long chain branches of the molecular chains forming the polymer.Also disclosed is a process for making the polymer by high energy radiation of a normally solid, high molecular weight, linear, propylene polymer in a reduced active oxygen environment, maintaining the irradiated material in such environment for a specific period of time, and then deactivating free radicals in the material.Further disclosed is the use of the strain hardening polymer in extensional flow operations such as, for example, extrusion coating, film production, foaming and thermoforming.

Abstract: An epoxidized diene block polymer comprising at least interior and exterior diene blocks wherein the exterior diene blocks contain a greater concentration of di-, tri- and tetrasubstituted olefinic epoxides than the interior blocks and wherein the exterior blocks contain from 0.2 to 10 Meq of olefinic epoxides per gram of exterior blocks and the molecular weights of the exterior blocks are from 3000 to 50,000 and the molecular weights of the interior blocks are from 15,000 to 200,000.