A composition containing polytetrafluoroethylene and substantially free from a compound represented by Formula (3):

(H(CF.sub.2).sub.8SO.sub.3).sub.qM.sup.2

wherein M.sup.2 is H, a metal atom, NR.sup.5.sub.4 (where R.sup.5s may be the same as or different from each other and are each H or an organic group having 1 to 10 carbon atoms), an imidazolium optionally having a substituent, a pyridinium optionally having a substituent, or a phosphonium optionally having a substituent, and q is 1 or 2. Also disclosed is a molded boy including the composition.

A composition containing polytetrafluoroethylene and substantially free from a compound represented by Formula (3):

(H(CF.sub.2).sub.8SO.sub.3).sub.qM.sup.2

wherein M.sup.2 is H, a metal atom, NR.sup.5.sub.4 (where R.sup.5s may be the same as or different from each other and are each H or an organic group having 1 to 10 carbon atoms), an imidazolium optionally having a substituent, a pyridinium optionally having a substituent, or a phosphonium optionally having a substituent, and q is 1 or 2. Also disclosed is a molded boy including the composition.

The present invention is directed to a process for separating an olefm copolymer from volatile gases using a flash separator. The flash separator can be used with a solution or high pressure process. The mass transport of volatile gases from the viscous polymer melt is increased.

A belt drier arrangement for drying an aqueous polymer gel and for comminuting the dried polymer gel to give dried polymer particles, having: a belt drier having a drier setup and a conveyor belt for receiving and for drying the aqueous polymer gel to give a dry cake or fragments on a receiving surface of the conveyor belt, and a comminution arrangement, disposed downstream of the drier setup in product flow direction, for comminution of the dried polymer gel of the dry cake or fragments to give dried comminuted polymer particles. The comminution arrangement has a comminutor in the form of a milling drum which is disposed with an upper working line of a working edge of the milling drum at the level of or above a receiving surface of a conveyor belt, for mill processing of the dry cake or of the fragments, where the milling drum is designed to eject comminuted dried polymer particles of the dry cake or of the fragments in the downward direction.

A belt drier arrangement for drying an aqueous polymer gel and for comminuting the dried polymer gel to give dried polymer particles, having: a belt drier having a drier setup and a conveyor belt for receiving and for drying the aqueous polymer gel to give a dry cake or fragments on a receiving surface of the conveyor belt, and a comminution arrangement, disposed downstream of the drier setup in product flow direction, for comminution of the dried polymer gel of the dry cake or fragments to give dried comminuted polymer particles. The comminution arrangement has a comminutor in the form of a milling drum which is disposed with an upper working line of a working edge of the milling drum at the level of or above a receiving surface of a conveyor belt, for mill processing of the dry cake or of the fragments, where the milling drum is designed to eject comminuted dried polymer particles of the dry cake or of the fragments in the downward direction.

A process for producing a modified polyphenylene ether resin having a purity of more than 99.4%, comprising steps of graft modification, water rinse, and extraction as well as phase splitting, is disclosed that step of separating out powder during purification is no needed, and the solvent for use in performing dissolving of or/and extraction of polyphenylene ether resin can be recycled for future use, so that the manufacturing process is simple and uses less solvent as compared to the prior art, and further helps to conserve resources and is environmentally friendly.

A process for producing a modified polyphenylene ether resin having a purity of more than 99.4%, comprising steps of graft modification, water rinse, and extraction as well as phase splitting, is disclosed that step of separating out powder during purification is no needed, and the solvent for use in performing dissolving of or/and extraction of polyphenylene ether resin can be recycled for future use, so that the manufacturing process is simple and uses less solvent as compared to the prior art, and further helps to conserve resources and is environmentally friendly.

A method for preparing an aqueous polyacrylamide solution is disclosed. The method comprises:hydrating acrylonitrile in water in presence of a biocatalyst capable of converting acrylonitrile to acrylamide so as to obtain an acrylamide solution,directly polymerizing the acrylamide solution so as to obtain a polyacrylamide gel, anddirectly dissolving the polyacrylamide gel by addition of water so as to obtain an aqueous polyacrylamide solution.

A method for preparing an aqueous polyacrylamide solution is disclosed. The method comprises:hydrating acrylonitrile in water in presence of a biocatalyst capable of converting acrylonitrile to acrylamide so as to obtain an acrylamide solution,directly polymerizing the acrylamide solution so as to obtain a polyacrylamide gel, anddirectly dissolving the polyacrylamide gel by addition of water so as to obtain an aqueous polyacrylamide solution.

The present invention relates to a process for the production of copolymers comprising: (i) forming a reaction mixture comprising an elastomer and a vinyl aromatic compound; (ii) introducing the reaction mixture to a reaction vessel; and (iii) performing a polymerisation reaction wherein steps (i)-(iii) are performed in that order to obtain a copolymer comprising: (a) a phase comprising a reaction product of the elastomer with the vinyl aromatic compound; and (b) a phase comprising a reaction product of the vinyl aromatic compound wherein a sample of the reactor contents is obtained during step (iii) to determine of the formed copolymer: the content of phase (b); and/or.circle-solid.the molecular weight of phase (b) wherein the determination of the content of phase (b) in the formed copolymer and the molecular weight of phase (b) is performed by a method comprising isolation of phase (b) from the sample of the formed copolymer and subjecting the obtained phase (b) to molecular analysis. Such process allows for the determination of the content N of the phase (b) and of the molecular weight thereof in a quick and efficient manner, allowing for adjustment of process parameters such that the production of products that not correspond to the desired product quality is minimised.