Methods for screening molecules or moieties for their ability to crosslink are disclosed. An aromatic carbonate, aromatic ester, or aliphatic ester group is attached to the molecule to mimic the presence of a polymer. A solution of the modified molecule is irradiated, and the first-order kinetic rate constant is measured. If the rate constant is high enough or a threshold amount of the molecule is consumed, a polymer is synthesized using the molecule/moiety as an endcap or co-monomer. The polymer is irradiated, and the increase in crosslink density and the gel formation percentage are determined. These parameters, if high enough, indicate the suitability of the molecule/moiety to act as a crosslinking agent, particularly for polycarbonates. Alternatively, the molecule/moiety may be identified as suitable solely by its first-order kinetic rate constant.

The invention relates to an efficient continuous method for producing polycarbonates according to the phase interface method.

The invention relates to an efficient continuous method for producing polycarbonates according to the phase interface method.

Provided is a branched polycarbonate resin, including a constituent unit represented by the general formula (I′).

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A copolycarbonate included 2-95 mole percent of high heat carbonate units derived from a high heat aromatic dihydroxy monomer, wherein a polycarbonate homopolymer derived from the high heat aromatic dihydroxy monomer has a glass transition temperature of 175-330 C determined by differential scanning calorimetry as per ASTM D3418 with a 20 C/min heating rate, and 5-98 mole percent of a low heat carbonate units derived from a low heat aromatic monomer, wherein a polycarbonate homopolymer derived from the low heat aromatic monomer has a glass transition temperature of less than 170 C determined by differential scanning calorimetry as per ASTM D3418 with a 20 C/min heating rate, each based on the sum of the moles of the carbonate units; and a sulfur-containing stabilizer compound, wherein the sulfur-containing stabilizer compound is a thioether carboxy compound, a thioether dicarboxy compound, a thioether ester compound, or a combination thereof, wherein the sulfur-containing stabilizer compound is present in an amount effective to provide 5-50 parts per million by weight of added sulfur, based on the total parts by weight of the copolycarbonate, wherein a source of the added sulfur is the sulfur-containing stabilizer.

A copolycarbonate included 2-95 mole percent of high heat carbonate units derived from a high heat aromatic dihydroxy monomer, wherein a polycarbonate homopolymer derived from the high heat aromatic dihydroxy monomer has a glass transition temperature of 175-330 C determined by differential scanning calorimetry as per ASTM D3418 with a 20 C/min heating rate, and 5-98 mole percent of a low heat carbonate units derived from a low heat aromatic monomer, wherein a polycarbonate homopolymer derived from the low heat aromatic monomer has a glass transition temperature of less than 170 C determined by differential scanning calorimetry as per ASTM D3418 with a 20 C/min heating rate, each based on the sum of the moles of the carbonate units; and a sulfur-containing stabilizer compound, wherein the sulfur-containing stabilizer compound is a thioether carboxy compound, a thioether dicarboxy compound, a thioether ester compound, or a combination thereof, wherein the sulfur-containing stabilizer compound is present in an amount effective to provide 5-50 parts per million by weight of added sulfur, based on the total parts by weight of the copolycarbonate, wherein a source of the added sulfur is the sulfur-containing stabilizer.

A process for preparing polycarbonate by the phase interface process in the presence of at least one catalyst, wherein immediately after the optionally first addition of the at least one catalyst, from 0.01 to 20 J/kg of mixing energy is introduced into the system comprising the at least one catalyst within a time of from 2 to 1200 s. A mixture, an organic phase, and a process for distributing at least one catalyst in a system comprising an organic phase and an aqueous phase are also disclosed herein.

A process for preparing polycarbonate by the phase interface process in the presence of at least one catalyst, wherein immediately after the optionally first addition of the at least one catalyst, from 0.01 to 20 J/kg of mixing energy is introduced into the system comprising the at least one catalyst within a time of from 2 to 1200 s. A mixture, an organic phase, and a process for distributing at least one catalyst in a system comprising an organic phase and an aqueous phase are also disclosed herein.

A polycarbonate resin composition, a molded article, a polycarbonate resin, and an end-capping agent for polycarbonate resins are provided. The polycarbonate resin composition contains: a polycarbonate resin having a terminal structure represented by Formula (A) and having a viscosity average molecular weight from 1×10.sup.4 to 5×10.sup.4, and a stabilizer. In Formula (A), R.sup.1 is selected from the group consisting of a hydrogen atom, halogen atoms, linear alkyl groups having from 1 to 9 carbons, branched alkyl groups having from 3 to 9 carbons, linear alkenyl groups having from 2 to 9 carbons, branched alkenyl groups having from 3 to 9 carbons, and aryl groups having from 6 to 12 carbons; and R.sup.2 to R.sup.7 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having from 1 to 9 carbons, and alkoxy groups having from 1 to 9 carbons. ##STR00001##

A sheet formed from carbon fiber reinforced thermoplastic resin with high moldability, and a production method of said resin is provided. This sheet is formed from a carbon fiber reinforced thermoplastic resin that contains carbon fibers, dichloromethane, and a thermoplastic resin containing at least one of a polycarbonate resin and a polyarylate resin. The aforementioned at least one of a polycarbonate resin and a polyarylate resin has a terminal structure derived from a monohydric phenol represented by formula (1) and a constituent unit derived from a dihydric phenol, and the content of the dichloromethane contained in the sheet is 10-10,000 ppm by mass. (In formula (1), R.sub.1 represents an alkyl group with 8-36 carbons, or an alkenyl group with 8-36 carbons, and R.sub.2-R.sub.5 independently represent a hydrogen, a halogen, an alkyl group with 1-20 carbons optionally having a substituent, or an aryl group with 6-12 carbons optionally having a substituent.) ##STR00001##