摘要:
Polyetherimide resins which crystallize from the melt contain crystallizing repeating units based on biphenoldianhydride or hydroquinone dianhydride and a linear aromatic diamine. The melt crystalline polyetherimides exhibit improved solvent resistance. The melt crystalline polymers retain the advantageous properties associated with their known amorphous polyetherimide counterparts.
摘要:
A poly(arylene ether) copolymer is the product of oxidative copolymerization of monomers including a monohydric phenol and a dihydric phenol. It has an intrinsic viscosity of about 0.04 to about 0.15 deciliter per gram and, on average, about 1.8 to about 2 hydroxyl groups per molecule. The poly(arylene ether) copolymer is enriched in low molecular weight copolymer chains and copolymer chains that include a terminal unit derived from the dihydric phenol.
摘要:
Novel poly(imide-siloxane) block copolymers and a process for their preparation are disclosed. The process of this invention involves reacting a hydroxy-terminated polyimide oligomer with a siloxane oligomer, which has reactive end groups capable of displacement by reaction with the hydroxyl groups of the hydroxy-terminated polyimide oligomer.
摘要:
High molecular weight aromatic carbonate resin comprised of the polymerized reaction products of:(i) at least one dihydric phenol;(ii) a carbonate precursor; and(iii) an amount at least effective to improve the impact properties of said resin of at least one polymer selected from polymers represented by the formula ##STR1## thereof; wherein A is selected from the divalent residues of at least one polymerized and fully hydrogenated conjugated alkadiene and has a weight average molecular weight of at least about 600, and X is independently selected from halogen radicals.At lower amounts of (iii) these resins exhibit improved impact properties, while at higher amounts of (iii) the resins exhibit rubbery and elastomeric characteristics.
摘要:
Polyetherimide oligomers are end functionalized with aryl hydroxy groups by reacting mixtures of bisphenol-A dianhydride, arylene diamines and aryl aminoalcohols. The oligomers are reactive with other polymer precursors, such as bisphenol-A and phosgene to provide segmented block copolymers of improved toughness and compatibility with other resins.
摘要:
A thermoplastic composition includes compatible blends of a mixed polycarbonate comprising units derived from a first dihydric phenol, which is a bis(hydroxyaryl) sulfone, a second dihydric phenol; and one or more thermoplastic condensation polymers containing hetero groups.
摘要:
A method is disclosed for preparing carborane-siloxane polymers directly from carborane which comprises reacting and polymerizing a dilithio salt of a carborane with a bis-halo-ended siloxane. This novel method offers the advantage of eliminating the expensive and time-consuming preparation of certain monomer intermediates of carborane employed in the preparation of carborane-siloxane polymers.
摘要:
A composition includes at least 15 weight percent of a low intrinsic viscosity, bifunctional poly(arylene ether) and at least 20 weight percent of a nonhalogenated solvent. The bifunctional poly(arylene ether)s are substantially and unexpectedly more soluble than their monofunctional analogs. The compositions are useful as concentrates to add bifunctional poly(arylene ether)s to thermosets.
摘要:
A poly(arylene ether) may be fractionated into higher and lower molecular weight fractions by forming a mixture that includes a poly(arylene ether) starting material, a first solvent that is dichloromethane, bromochloromethane, dibromomethane, or a mixture thereof, and a second solvent different from the first solvent having a Hildebrand solubility parameter of about 16 to about 22 megapascal1/2. The mixture separates into fractions containing higher and lower molecular weight poly(arylene ether)s.
摘要:
A poly(arylene ether) copolymer is the product of oxidative copolymerization of monomers including a monohydric phenol and a dihydric phenol. It has an intrinsic viscosity of about 0.04 to about 0.15 deciliter per gram and, on average, about 1.8 to about 2 hydroxyl groups per molecule. The poly(arylene ether) copolymer is enriched in low molecular weight copolymer chains and copolymer chains that include a terminal unit derived from the dihydric phenol.