The instant invention concerns a process for fragmenting a polymer chain, comprising an oxidative degradation step wherein the polymer chain is contacted with a reduced form of a metal M and an oxidant such as dioxygen, and wherein the polymer carries covalently bound chemical groups acting as a ligand of said reduced form of the metal M.

The invention also relates to methods making use of this fragmentation process as a first step of a degradation process of the polymer especially useful for avoiding the negative impact of a polymer to the environment. In this connection, the invention relates to the use of polymers carrying chemical groups acting as a ligand for a reduced form of a metal M, as a polymer biodegradable in an environment wherein the reduced form of a metal M is present.

The instant invention concerns a process for fragmenting a polymer chain, comprising an oxidative degradation step wherein the polymer chain is contacted with a reduced form of a metal M and an oxidant such as dioxygen, and wherein the polymer carries covalently bound chemical groups acting as a ligand of said reduced form of the metal M.

The invention also relates to methods making use of this fragmentation process as a first step of a degradation process of the polymer especially useful for avoiding the negative impact of a polymer to the environment. In this connection, the invention relates to the use of polymers carrying chemical groups acting as a ligand for a reduced form of a metal M, as a polymer biodegradable in an environment wherein the reduced form of a metal M is present.

The present invention relates to filtration media made from melt-blown fibers having improved barrier properties. The melt-blown fibers in the filtration media of the invention are made of a visbroken metallocene-catalyzed propylene homopolymer composition with specified melting temperature Tm and molecular weight distribution (MWD).

The present invention relates to filtration media made from melt-blown fibers having improved barrier properties. The melt-blown fibers in the filtration media of the invention are made of a visbroken metallocene-catalyzed propylene homopolymer composition with specified melting temperature Tm and molecular weight distribution (MWD).

The present invention relates to melt-blown webs having no shots and improved barrier properties, whereby the melt-blown webs are made of a visbroken metallocene-catalyzed propylene homopolymer composition with specified melting temperature T.sub.m, content of 2,1 erythro regiodefects and molecular weight distribution (MWD).

The present invention relates to melt-blown webs having no shots and improved barrier properties, whereby the melt-blown webs are made of a visbroken metallocene-catalyzed propylene homopolymer composition with specified melting temperature T.sub.m, content of 2,1 erythro regiodefects and molecular weight distribution (MWD).

A method for producing low molecular weight polytetrafluoroethylene which includes: (1) feeding into an airtight container in the absence of oxygen: high molecular weight polytetrafluoroethylene: and a halogenated polymer having a halogen atom other than a fluorine atom; and (2) irradiating the high molecular weight polytetrafluoroethylene to provide low molecular weight polytetrafluoroethylene having a melt viscosity at 380° C. of 1.0×10.sup.2 to 7.0×10.sup.5 Pa.Math.s.

A method for producing low molecular weight polytetrafluoroethylene which includes: (1) feeding into an airtight container in the absence of oxygen: high molecular weight polytetrafluoroethylene: and a halogenated polymer having a halogen atom other than a fluorine atom; and (2) irradiating the high molecular weight polytetrafluoroethylene to provide low molecular weight polytetrafluoroethylene having a melt viscosity at 380° C. of 1.0×10.sup.2 to 7.0×10.sup.5 Pa.Math.s.

A fluorine-containing resin particle contains 0 or more and 30 or less carboxyl groups per 10.sup.6 carbon atoms and 0 ppm or more and 3 ppm or less of a basic compound.

A fluorine-containing resin particle contains 0 or more and 30 or less carboxyl groups per 10.sup.6 carbon atoms and 0 ppm or more and 3 ppm or less of a basic compound.