A block comprised of a copolymer is obtained by ring-opening polymerization of a cyclic polyarylene sulfide, so that a block copolymer is produced to have a maximum peak molecular weight measured by size exclusion chromatography (SEC) in a range of not less than 2,000 and less than 2,000,000 and have a unimodal molecular weight distribution in this range.

A block comprised of a copolymer is obtained by ring-opening polymerization of a cyclic polyarylene sulfide, so that a block copolymer is produced to have a maximum peak molecular weight measured by size exclusion chromatography (SEC) in a range of not less than 2,000 and less than 2,000,000 and have a unimodal molecular weight distribution in this range.

Process for the production of a mercapto-terminated liquid polymer with the formula HS—R—(Sy —R)t —SH, wherein each R is independently selected from branched alkanediyl or branched arenediyi groups and groups with the structure —(CH2)p—O—(CH2)q—O—(CH2)r- and wherein 0-20% of the number of R-groups in the polymer are branched alkanediyl or branched arenediyl groups and 80-100% of the number of R-groups in the polymer have the structure —(CH2)p—O—(CH2)r—, wherein t has a value in the range 1-60, y is an average value in the range 1.0-1.5, q is an integer the range 1 to 8, and p and r are integers the range 1-10. The resulting polymer has an improved ability of recovering its original shape after release from deforming compression forces and improved tendency to recover during the application of those forces.

Process for the production of a mercapto-terminated liquid polymer with the formula HS—R—(Sy —R)t —SH, wherein each R is independently selected from branched alkanediyl or branched arenediyi groups and groups with the structure —(CH2)p—O—(CH2)q—O—(CH2)r- and wherein 0-20% of the number of R-groups in the polymer are branched alkanediyl or branched arenediyl groups and 80-100% of the number of R-groups in the polymer have the structure —(CH2)p—O—(CH2)r—, wherein t has a value in the range 1-60, y is an average value in the range 1.0-1.5, q is an integer the range 1 to 8, and p and r are integers the range 1-10. The resulting polymer has an improved ability of recovering its original shape after release from deforming compression forces and improved tendency to recover during the application of those forces.

A method for forming a high melt viscosity polyarylene sulfide is provided. The method comprises reacting a sulfur source with a dihaloaromatic compound during a first stage to form an arylene sulfide prepolymer having halogen end groups; and thereafter, reacting the arylene sulfide prepolymer with a secondary sulfur source during a second stage to form the polyarylene sulfide.

A method for forming a high melt viscosity polyarylene sulfide is provided. The method comprises reacting a sulfur source with a dihaloaromatic compound during a first stage to form an arylene sulfide prepolymer having halogen end groups; and thereafter, reacting the arylene sulfide prepolymer with a secondary sulfur source during a second stage to form the polyarylene sulfide.

Provided are a continuous production method and a continuous production apparatus utilizing the solution polycondensation for aromatic cyclic oligomers, which achieve a good space-time yield and are inexpensive and simple. The continuous production method includes: (a) supplying a polymerization solvent and a reaction raw material to a continuous production apparatus; (b) performing a polymerization reaction in the reaction vessels to form a reaction mixture; (c) removing water in gas phase parts of the reaction vessels from the reaction vessels; and (d) successively moving the reaction mixture to each of the reaction vessels; the steps (a), (b), (c), and (d) being performed in parallel; wherein an amount of the polymerization solvent in the reaction vessel positioned furthest downstream in a movement direction of the reaction mixture is not less than 1 L and not greater than 50 L per 1 mol of arylene units in the reaction raw material.

Provided are a continuous production method and a continuous production apparatus utilizing the solution polycondensation for aromatic cyclic oligomers, which achieve a good space-time yield and are inexpensive and simple. The continuous production method includes: (a) supplying a polymerization solvent and a reaction raw material to a continuous production apparatus; (b) performing a polymerization reaction in the reaction vessels to form a reaction mixture; (c) removing water in gas phase parts of the reaction vessels from the reaction vessels; and (d) successively moving the reaction mixture to each of the reaction vessels; the steps (a), (b), (c), and (d) being performed in parallel; wherein an amount of the polymerization solvent in the reaction vessel positioned furthest downstream in a movement direction of the reaction mixture is not less than 1 L and not greater than 50 L per 1 mol of arylene units in the reaction raw material.

A seawall comprising a base with a top, a plurality of extensions on the top of the base, and an adhesive or sealant securing the extensions to the base. Each extension comprises a plurality of spaced apart rubber poles extending generally in a direction horizontal to the sea floor, and an outer rubber covering surrounding the poles. A method of increasing the height of a seawall comprising the steps of placing a plurality of the extensions on top of the seawall with the poles extending substantially parallel to the sea floor, and securing the extensions to the top of the seawall.

Elastomeric copolymer with a high sulfur content, comprising sulfur in a quantity higher than or equal to 40% by weight, preferably ranging from 55% by weight to 90% by weight, with respect to the total weight of said elastomeric copolymer, and at least one monomer having general formula (I): CH.sub.2═CH—(CH.sub.2).sub.y-(X).sub.n-(X).sub.m-(CH.sub.2).sub.x—CH═CH.sub.2 (I) wherein: X represents a sulfur atom, a selenium atom, a tellurium atom, preferably a sulfur atom, a selenium atom; y and x, equal to or different from one another, are a whole number ranging from 0 to 4; n and m, equal to or different from one another, are a whole number ranging from 0 to 3, at least one of n and m being equal to 1; said monomer being present in a quantity lower than or equal to 60% by weight, preferably ranging from 10% by weight to 45% by weight, with respect to the total weight of said elastomeric copolymer; provided that, in the case wherein in said general formula (I) X is sulfur, y and x are 1, at least one of n and m must be different from 1 and the sum of n+m must be different from 1. Said elastomeric copolymer with a high sulfur content can be advantageously used in a great many applications such as, for example, thermal insulation, conveyor