A depolymerizer is formed by grafting thiol groups on parts of the double bonds of a polymer of linear conjugated diene monomer. The linear conjugated diene monomer can be 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 2,3-dimethyl-1,3-pentadiene, 2-phenyl-1,3-butadiene, or 4,5-diethyl-1,3-octadiene. The depolymerizer has a weight average molecular weight of 1000 to 400000.

Crumb rubber obtained from recycled tires is subjected to an interlinked substitution process. The process utilizes a reactive component that interferes with sulfur bonds. The resulting treated rubber exhibits properties similar to those of the virgin composite rubber structure prior to being granulated, and is suitable for use in fabricating new tires, engineered rubber articles, and asphalt rubber for use in waterproofing and paving applications.

Crumb rubber obtained from recycled tires is subjected to an interlinked substitution process. The process utilizes a reactive component that interferes with sulfur bonds. The resulting treated rubber exhibits properties similar to those of the virgin composite rubber structure prior to being granulated, and is suitable for use in fabricating new tires, engineered rubber articles, and asphalt rubber for use in waterproofing and paving applications.

A conjugated diene copolymer has a covalent bond reversibly dissociated and added by heat, and has at least two peaks in each of curves of molecular weight distributions measured at 40° C. and 60° C. by gel permeation chromatography, wherein a change rate of the proportion of the area of the peak having the lowest molecular weight in measurement at 60° C. to the proportion of the area of the peak having the lowest molecular weight in measurement at 40° C.

A sulfur-modified chloroprene polymer latex includes an emulsifier and a sulfur-modified chloroprene polymer obtained by modifying a chloroprene polymer (A) with sulfur (B), wherein the sulfur amount Y in the sulfur-modified chloroprene polymer and the z-average particle size X of the sulfur-modified chloroprene polymer satisfy formulae (1) to (3) (formula (1): 0.10<Y<0.60; formula (2): 120<X<320; and formula (3): Y<0.0025X−0.20), the total amount of a chloroprene monomer (A-1) and a monomer (A-2) copolymerizable with the chloroprene monomer which constitute the chloroprene polymer is 100 parts by mass, the amount of sulfur (B) contained in the sulfur-modified chloroprene polymer is Y parts by mass, and the z-average particle size of the sulfur-modified chloroprene polymer is X nm. The sulfur-modified chloroprene polymer latex composition can also include a metal oxide (C), a cross-linking accelerator (D), and an antioxidant (E).

A sulfur-modified chloroprene polymer latex includes an emulsifier and a sulfur-modified chloroprene polymer obtained by modifying a chloroprene polymer (A) with sulfur (B), wherein the sulfur amount Y in the sulfur-modified chloroprene polymer and the z-average particle size X of the sulfur-modified chloroprene polymer satisfy formulae (1) to (3) (formula (1): 0.10<Y<0.60; formula (2): 120<X<320; and formula (3): Y<0.0025X−0.20), the total amount of a chloroprene monomer (A-1) and a monomer (A-2) copolymerizable with the chloroprene monomer which constitute the chloroprene polymer is 100 parts by mass, the amount of sulfur (B) contained in the sulfur-modified chloroprene polymer is Y parts by mass, and the z-average particle size of the sulfur-modified chloroprene polymer is X nm. The sulfur-modified chloroprene polymer latex composition can also include a metal oxide (C), a cross-linking accelerator (D), and an antioxidant (E).

A polymer having a hydrophobic polymer chain derived from monomers of farnesene and other optional monomers, such as dienes and vinyl aromatics. The polymer also includes one or more terminal functional groups, such as an amino group, a glycidyl group, a carboxylic acid group, a (meth)acrylate group, a silane group, an isocyanate group, an acetoacetate group, a phenolic group, and a hydroxyl group. Functional groups, such as carboxylic acids, may also be grafted along the hydrophobic polymer chain. The polymer may be incorporated in curable compositions that optionally include one or more polymer resins having similar functional groups. Methods for preparing the curable polymer compositions are also provided. The curable or cured form of the polymer composition may be used in various products, such as a sealant, a coating, a caulk, an electric potting compound, a membrane, a sponge, a foam, an adhesive, or a propellant binder.

A polymer having a hydrophobic polymer chain derived from monomers of farnesene and other optional monomers, such as dienes and vinyl aromatics. The polymer also includes one or more terminal functional groups, such as an amino group, a glycidyl group, a carboxylic acid group, a (meth)acrylate group, a silane group, an isocyanate group, an acetoacetate group, a phenolic group, and a hydroxyl group. Functional groups, such as carboxylic acids, may also be grafted along the hydrophobic polymer chain. The polymer may be incorporated in curable compositions that optionally include one or more polymer resins having similar functional groups. Methods for preparing the curable polymer compositions are also provided. The curable or cured form of the polymer composition may be used in various products, such as a sealant, a coating, a caulk, an electric potting compound, a membrane, a sponge, a foam, an adhesive, or a propellant binder.

Modified silicas, having the following physicochemical parameters: a CTAB.sub.mod of <200 m.sup.2/g, a BET.sub.MP of 50-500 m.sup.2/g, a CTAB.sub.mod-BET.sub.MP of <0 m.sup.2/g, a carbon content of >0.5% by weight, a mode.sub.mod from CPS particle size determination of >50 nm, a d75.sub.mod from CPS particle size determination of 20-150 nm, a R.sub.min from Hg pore size determination, pressurized of <10 nm, and a sulfur content of ≤1.50% by weight.

A sulfur-crosslinkable rubber mixture comprising at least the following constituents: at least one diene rubber and at least one liquid, linear modified diene polymer A, modified with a functional group of formula I) at only one chain end, the number of functional groups per molecule being on average from 0.8 to 1
(R.sup.1R.sup.2R.sup.3)Si—X—NH—C(═O)—O—,  I)
where R.sup.1, R.sup.2 and R.sup.3 independently of one another are selected from methoxy groups, ethoxy groups, phenoxy groups, methyl groups, ethyl groups and phenyl groups, with in each case at least one of the groups R.sup.1, R.sup.2 and R.sup.3 being a methoxy group, an ethoxy group or a phenoxy group, and where X is a divalent alkyl group having 1 to 6 carbon atoms.