摘要:
Polyurethane/urea elastomer compositions which retain their dimensions at elevated temperatures. These polyurethane/urea elastomers surprisingly have improved green strength or dimensional stability upon demolding at typical mold temperatures of 80 to 130 C and remain dimensionally stable throughout the post cure process which is typically overnight at about 100 C. They are useful in indirect food contact or dry food contact applications since the compositions use trimethylene glycol di(p-aminobenzoate) as a chain extender or curative. The polyurethane/urea elastomers may be prepared by reacting toluene diisocyanate prepolymers with trimethylene glycol di(p-aminobenzoate). The toluene diisocyanate prepolymers are reaction products of toluene diisocyanate containing at least 25% by weight of the 2,6-isomer, preferentially at least 35%, more preferentially at least 45%, and most preferentially 60% with polyols such as polyoxyalkylene polyether polyols like polytetramethylene glycol, polypropylene glycol and polyethylene glycol, polyester polyols, polycaprolactone polyols, polycarbonate polyols, polybutadiene polyols or mixtures thereof.
摘要:
Polyurethanes having improved properties are obtained from polyester-polyether co-prepolymers. These co-prepolymers are homogeneous, clear liquids of varying viscosity and can be reacted with curing agents to yield clear homogeneous elastomers of various hardness. Cast elastomers prepared from such co-prepolymers have physical properties at least as good as premium polyester urethanes currently available, and have hydrolytic stability and low temperature properties better than such premium polyester urethanes and comparable to premium polyether urethanes, with the cost being comparable to the lower cost of the conventional polyester systems.
摘要:
This invention comprises the novel composition formed by mixing (A) a chromium tris-diorgano-orthophosphate of the general formula Cr[OP(O) (OR).sub.2 ].sub.3 wherein R can be an alkyl, alkoxyalkyl or cycloalkyl group of one to about eight carbon atoms and the chlorinated and brominated derivatives thereof, (B) an alkyl aluminum compound of the general formula R'.sub.2 R"Al in which each R' and R" can be an alkyl group of 1 to 6 carbon atoms and each R" can also be a hydrogen atom, and (C) a halogenated olefin of four to about eight carbon atoms containing at least four halogen atoms at least two of which are attached to doubly bonded carbon atoms.This invention also comprises the use of this novel combination as a catalyst for the polymerization of ethylene alone or with propylene and other olefins. This invention also comprises the polymer products prepared by said method.
摘要:
The reaction product of a chromium tris-diorgano-orthophosphate and an alkyl aluminum halide is a catalyst for olefin polymerization and for alkylation of aromatic hydrocarbons with olefins.
摘要:
Borates, compositions comprising chiral (cyclic and acyclic) and achiral (cyclic and acyclic) borates; chiral (cyclic and acyclic) and achiral (cyclic and acyclic) biborates; and methods for their synthesis. Additionally, a significantly improved synthetic protocol for the synthesis of wide range of boronates starting from borates or biborates and Grignard or organolithium reagents that can be used for kilo lab and commercial scale production.
摘要:
Ranges of glycidyl methacrylate containing acrylic resin monomer compositions and polymer properties which are suitable to be used in chain extension processes for Poly(lactic acid) or Polylactide (PLA). The selection of monomer compositions and molecular weight ranges of the acrylic chain extender resins, and the examples of chain extension reaction between the acrylic chain extender and PLA are also provided.
摘要:
This invention comprises novel organic-solvent-soluble nickel bis-diorgano-orthophosphates and their preparation by the reaction of certain simple salts or esters of divalent nickel with certain non-aromatic triorgano orthophosphates free of aliphatic unsaturation and separation of the novel compounds. The simple salts or esters include preferably the halides, nitrates and acetates of divalent nickel.This invention further comprises the use of these novel compounds, preferably in solution, as catalysts. When used in conjunction with alkyl aluminum halides, controlled oligomerization of ethylene, propylene and other olefins is achieved with the formation of polymers with low degrees of polymerization, e.g. 2 to 10, preferably no more than about 6 mers. When certain vanadium catalysts are added to these combined catalysts, high polymers of such monomers are achieved with significant residual aliphatic unsaturation.
摘要:
The reaction product of a chromium tris-diorganoorthophosphate and an alkyl aluminum halide is a catalyst for olefin polymerization and for alkylation of aromatic hydrocarbons with olefins.
摘要:
Improved curing agents having long pot life for use with urethane elastomers are prepared by reacting orthochloroaniline, an ester of anthranilic acid, and formaldehyde in selected molar ratios in an acid medium.
摘要:
Novel organic-solvent-soluble nickel bis-diorgano-orthophosphates are prepared by the reaction of certain simple salts or esters of divalent nickel with certain non-aromatic triorgano orthophosphates free of aliphatic unsaturation. The simple salts or esters include preferably the halides, nitrates and acetates of divalent nickel.These novel compounds, preferably in solution, are used as catalysts. When used in conjunction with alkyl aluminum halides, controlled oligomerization of ethylene, propylene and other olefins is achieved with the formation of polymers with low degrees of polymerization, e.g. 2 to 10, preferably no more than about 6 mers. When certain vanadium catalysts are added to these combined catalysts, high polymers of such monomers are achieved with significant residual aliphatic unsaturation.