A procedure for improved temperature control in controlled radical polymerization processes is disclosed. The procedure is directed at controlling the concentration of the persistent radical in ATRP and NMP polymerizations procedures and the concentration of radicals in a RAFT polymerization process by feeding a reducing agent or radical precursor continuously or intermittently to the reaction medium through one of more ports.

A procedure for improved temperature control in controlled radical polymerization processes is disclosed. The procedure is directed at controlling the concentration of the persistent radical in ATRP and NMP polymerizations procedures and the concentration of radicals in a RAFT polymerization process by feeding a reducing agent or radical precursor continuously or intermittently to the reaction medium through one of more ports.

The present invention concerns type II photoinitiators for the free-radical crosslinking of silicone compositions, in particular acrylic silicone compositions. The present invention concerns a silicone composition C1 that can be crosslinked by exposure to radiation with a wavelength of between 300 and 450 nm, comprising: —at least one organopolysiloxane A comprising at least one methacrylate group bonded to a silicon atom, at least one organohydrogenopolysiloxane H comprising at least two, and preferably at least three hydrogen atoms each bonded to different silicon atoms, and —at least one free-radical photoinitiator P. The present invention also concerns the provision of a silicone composition that can be polymerized or crosslinked by free-radical process comprising a type II photoinitiator system suitable for crosslinking silicone compositions, in particular by exposure to radiation, and absorbing light radiation with a wavelength greater than 300 nm.

This invention relates to a non-phthalate catalyst system for olefin polymerization. The non-phthalate catalyst system comprises (a) a solid Ziegler-Natta catalyst composition comprising a transition metal, a Group 2 metal, and one or more halogens; and one or more internal electron donor compounds; and (b) one or more external electron donor compounds.

Acrylic copolymers that include the controlled placement of functional groups within the polymer structure are provided. The copolymers contain a reactive segment and a non-reactive segment and are manufactured via a controlled radical polymerization process. The copolymers are useful in the manufacture of adhesives and elastomers.

Acrylic copolymers that include the controlled placement of functional groups within the polymer structure are provided. The copolymers contain a reactive segment and a non-reactive segment and are manufactured via a controlled radical polymerization process. The copolymers are useful in the manufacture of adhesives and elastomers.

The invention provides a process for the preparation of a multimodal high density polyethylene (HDPE) having a melt flow rate (MFR.sub.2) of 0.1 to 4.0 g/10 min, said process comprising: (i) polymerising ethylene in a first polymerisation stage in the presence of a Ziegler-Natta catalyst to prepare a first ethylene homopolymer having a MFR.sub.2 from 10 to 500 g/10 min; (ii) polymerising ethylene in a second polymerisation stage in the presence of said catalyst and said first ethylene homopolymer to prepare an ethylene homopolymer mixture comprising said first ethylene homopolymer and a second ethylene homopolymer, said mixture having a MFR.sub.2 from 50 to 1000 g/10 min; and (iii) polymerising ethylene and at least one alpha-olefin comonomer in a third polymerisation stage in the presence of said catalyst and said ethylene homopolymer mixture to prepare said multimodal HDPE.

The present disclosure provides an elastomer composition, comprising, based on the total weight 100 wt. % of the elastomer composition: 1-50 wt. % of a modified ethylene propylene copolymer; 5-60 wt. % of a first silicone resin, the first silicone resin comprising at least one selected from the group consisting of the following: a hydroxyl-terminated silicone resin and an alkoxy-terminated silicone resin; 0.1-15 wt. % of a first crosslinking agent; 0.1-15 wt. % of a catalyst; and 10-85 wt. % of a filler. The elastomer composition provided by the present disclosure at least can be co-crosslinked in low temperature (approximately −20° C. to 60° C.) conditions. An elastomer prepared from the elastomer composition provided by the present disclosure has good mechanical properties and electrical insulation properties.

The present disclosure provides an elastomer composition, comprising, based on the total weight 100 wt. % of the elastomer composition: 1-50 wt. % of a modified ethylene propylene copolymer; 5-60 wt. % of a first silicone resin, the first silicone resin comprising at least one selected from the group consisting of the following: a hydroxyl-terminated silicone resin and an alkoxy-terminated silicone resin; 0.1-15 wt. % of a first crosslinking agent; 0.1-15 wt. % of a catalyst; and 10-85 wt. % of a filler. The elastomer composition provided by the present disclosure at least can be co-crosslinked in low temperature (approximately −20° C. to 60° C.) conditions. An elastomer prepared from the elastomer composition provided by the present disclosure has good mechanical properties and electrical insulation properties.

A new class of alkoxyamines, exhibiting improved stability on storage, especially in the presence of monomers and/or of solvent is described, particularly where the alkoxylamines are a new class of oligomeric alkoxyamines, which are obtained by addition of one or more monomeric entities to an alkoxyamine.