This technology is available from Temarex Corporation.
GRAFT COPOLYMERIZATION
Title: FLAME INITIATED GRAFT POLYMERIZATION
Inventor(s): S. Lee, R. Rengarajan
Disclosure 242 U.S. Patent 5,571,869
This invention relates to grafting polymer particles that are prepared by a free-radical addition polymerization mechanism using a flame produced by igniting a mixture of a combustible gas and an oxidant to heat at least a portion of the surface of a solid polymer particle to produce free-radicals thereon. At least one polymerizable ethylenically unsaturated monomer is contacted and reacted with the free-radicals formed on the surface of the polymer to form a graft thereon.
This technology overcomes the inherent drawbacks of some existing techniques for grafting monomers to polymers or polymer particles, such as degrading the polymer. This process imparts improved surface characteristics relating to compatibility or miscibility with other polymers, to form composites having enhanced mechanical properties.
The present invention relates to a solid-phase reaction, carried out either in a batch or continuous reactor, to form grafted chains substantially in the absence of both free-radical initiators and solvents, and without the need for irradiation equipment. Suitable solid polymers which can be used in the graft copolymerization process include any of various hydrocarbon based polymers which are amenable to free-radical generation by flame impingement such as PE, HDPE, PP, PS, PVC, PAN, PC, PI, PVAC, PVA, PU, polydienes, polyesters, and the like.
The advantages of this process are (1) energy efficient (i.e. low temperatures and low pressures), (2) that it does not require expensive or environmentally unfriendly (i.e. peroxide) free-radical initiators (FRI) or solvent recovery systems, and (3) operates in a dry, solvent-free phase.
Typical graft levels vary depending on the types of polymers and reactive monomers. The process is capable of producing various special purpose, reactive polymers that can be used in specialty plastics, engineering plastics, and as polymer compatibilizers. Also this process has excellent potential in the areas of hot melt super adhesives, for polymer blends and coatings.
The wide range of high-value added products make this a valued technology for those uses in which relatively high conversions rates can be achieved.
Title: POLYCARBONATE-G-POLYACRYLATE GRAFT COPOLYMERIZATION
Inventor(s): S. Lee, R. Sobocinski
Disclosure 197 U.S. Patent 5,510,429
This invention relates to a process for grafting an alkyl (alkyl)acrylate to a polycarbonate and the resulting polycarbonate-g-polyacrylate copolymer. The acrylate is grafted onto a polycarbonate, which is in the solid phase, at a carbon atom of the polycarbonate which before and after grafting has an sp3 electron configuration.
An important application for the graft copolymers is as compatibilizing agents for polymeric blends comprising a polycarbonate and a polyacrylate. The graft copolymerization process can be adapted to be carried out in either a batch, semi-batch or continuous mode.
An important advantage of this process is that the polycarbonate-g-polyacrylate is prepared in the solid phase, thus eliminating the need for solvents (i.e. the process is environmentally friendly) and for separation processes for removing the product copolymer from solvents. In addition, this technology results in lower mass transfer resistance and higher overall reaction rates.
This technology is ideally suitable for any application wherein conventional polycarbonate compositions are employed but wherein enhanced impact resistance, scratch resistance and/or UV resistance would be desirable such as appliance and power tool housings, automotive headlights and taillight lenses, aircraft parts, airport runway and highway markers, motorcycle helmets and face guards, windshields, and the like.
Title: GRAFT COPOLYMERIZATION IN SUPERCRITICAL MEDIA
Inventor(s): S. Lee, S. Kwak, F. Azzam
Disclosure 162 U.S. Patent 5,663,237
This invention provides a solution to the separation problems of solvents in a conventional grafting process by employing supercritical fluid (SCF) technology for graft copolymerization.
Conventional techniques for graft copolymerization use excessive amounts of toxic liquid solvents to dissolve the polymer, which in turn requires an expensive solvent recovery schemes in the process.
Supercritical processing can exploit non-toxic, non-flammable, and inexpensive solvents such as carbon dioxide, ethane, ethylene, propane, propylene, nitrous oxide, water and ammonia.
An advantage of this innovation is that the solvent can be completely recovered from the product (i.e. grafted copolymer) by simply depressurizing the system. Another advantage of this innovation is that one can graft copolymerize other reactive monomers to commodity polymers such as polyethylene, polypropylene, and polystyrene.
Graft polymer systems experimented with include poly(vinyl chloride)-g-poly(vinyl acetate), PVC-g-PVAc,; polypropylene-g-polystyrene, PP-g-PS; and polypropylene-g-poly(acrylic acid), PP-g-PAAc.
Potential non-limiting exemplary additional candidate graft polymer systems would include the following amorphous and crystalline polymers and monomers:
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polyethylene |
styrene, methacrylic acid, acrylamide | ||
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polystyrene |
acrylic acid, maleic anhydride, methyl acrylate | ||
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poly(methyl methacrylate) |
vinyl acetate, acrylic acid | ||
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polycarbonate |
butyl acrylate, styrene | ||
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polypropylene
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acrylonitrile, methyl methacrylate, maleic anhydride, methacrylic acid | ||
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poly(vinyl chloride) |
methyl methacrylate, acrylonitrile |
Polymer and polymer additives that are found in food, textiles, surfactants, cosmetics and the petroleum industries are all areas where supercritical fluid technology are finding widespread acceptance and use.
Title: POLYMERIZATION PROCESS AND THE POLYMERS THEREOF
Inventor(s): S. Lee, R. Rengarajan
Disclosure 110 U.S. Patent 5,079,302
A new process for making graft copolymers that can be used to impart specialty properties - including high impact strength, thermal stability, anti-static characteristics and biogradability. This process does not require use of environmentally hazardous solvents, thus eliminating the need for expensive solvent recovery.
A catalytic process for free radically induced polymerization and graft copolymerization of a free radically polymerizable monomer onto a compound in the presence of a free radical initiator and an organic catalyst and also in the presence or absence of an organic diluent where the organic catalyst is an alkenyl substituted cyanurate or isocyanurate and composition thereof.
This invention accomplishes the free radical polymerization of free radically polymerizable monomers or the free radical graft copolymerization of polyolefins and other high molecular weight polymers including elastomers, thermoplastics, thermoplastic elastomers, high performance polymers or combinations thereof with free radically polymerizable monomers and/or free radically grafted monomers.
The process can be carried out in a highly efficient catalytic process either in batch or continuous reactors (i.e. extruders, moving bed reactors, continuously stirred tank reactors, stirred tank reactors or the like).
Many of the graft copolymers of the present invention are novel and are ideally suited as compatabilizing agent for compatabilizing incompatible polymer blends giving rise to new polymer alloys.
New copolymers can be used to prepare polyolefin-polyaromatic olefin alloys such as polypropylene-polystyrene alloys. Other compatabilizing graft copolymers, but not restricted to, styrene grafted polyethylene, alkylated styrene grafted polyethylene, halogenated styrene grafted polyethylene, alkylated styrene grafted polypropylene, halogenated styrene grafted polypropylene, and the like.
The oligomers, cooligomers, polymers and copolymers useful for the polymerization/graft copolymerization process can be selected from the representative group consisting of: PE, PP, PB, PIB, PS, poly a-methylstyrene, PAN, polyisoprene, polybutadine, EPDM, polyvinylether, PVA\PVAL, polyacrylates, substituted polyacrylates, other polyolefins and polydienes and combinations and copolymers of any of these polymers.
The polymers derived from the unique process of this invention are useful in paints, adhesives, compatibilizers, composites, bulk polymers, bulk plastics, bulk elastomers, fabrics, fibers, fillers for sterilizable packaging, metal coatings, solidified radioactive wastes, microbial resistant copolymers, improved dyable fibers, paper reinforcing agents, and printable polymer films.