The present application relates to a method of performing living cationic polymerization of monomers by supermolecular anion-binding catalysis. It uses various simple Bronsted acids or adducts thereof with a monomer as the cationic initiator, and various hydrogen bond donors as the catalyst for binding and dissociating counter anions dynamically, to living and controlled polymerize one or more cationically polymerizable monomers to form a homopolymer or a copolymer. In the present application, the hydrogen-bond donor can exert non-covalent anion-binding interactions to dynamically and reversibly activate dormant covalent bond under mild conditions, in turn to precisely control the equilibrium between dormant covalent precursors and active cationic species, thereby achieving the precise control of the polymer's molecular weight, distribution and end group structure, and solving the environment-unfriendly relevant problems in traditional metal-based Lewis acid catalysis, which include extreme low polymerization temperature, restrict anhydrous requirement of the reaction, strict purification requirement of the monomer and catalysis-initiating system, metal residue in polymer or the like.

The present disclosure relates to tertiary amine co-initiators that demonstrate reduced leaching and which may be utilized in dental restoration and other biomedical applications. Embodiments of the present disclosure provide compounds and compositions for use in preparing polymers and light curable dental resin composites, as well as methods for preparing photocurable polymer-based dental restorative materials. In one or more disclosed embodiments, a co-initiator for use in preparing a polymer comprises a tertiary amine core and two or more pendant, terminal methacrylate groups. In some embodiments, the co-initiator may also act as a co-monomer in a co-polymerization reaction. ##STR00001##

The present disclosure relates to tertiary amine co-initiators that demonstrate reduced leaching and which may be utilized in dental restoration and other biomedical applications. Embodiments of the present disclosure provide compounds and compositions for use in preparing polymers and light curable dental resin composites, as well as methods for preparing photocurable polymer-based dental restorative materials. In one or more disclosed embodiments, a co-initiator for use in preparing a polymer comprises a tertiary amine core and two or more pendant, terminal methacrylate groups. In some embodiments, the co-initiator may also act as a co-monomer in a co-polymerization reaction. ##STR00001##

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.

Disclosed are catalyst compositions having an internal electron donor which includes a 3,6-di-substituted-1,2-phenylene aromatic diester. Ziegler-Natta catalyst compositions containing the present catalyst compositions exhibit very high hydrogen response, high activity, high selectivity and produce propylene-based olefins with high melt flow rate.

Disclosed are catalyst compositions having an internal electron donor which includes a 3,6-di-substituted-1,2-phenylene aromatic diester. Ziegler-Natta catalyst compositions containing the present catalyst compositions exhibit very high hydrogen response, high activity, high selectivity and produce propylene-based olefins with high melt flow rate.

Provided are a novel metallocene compound, a metallocene-supported catalyst, and a method of preparing a polyolefin using the same. The metallocene-supported catalyst according to the present disclosure exhibits a high polymerization activity even when the metallocene compound is supported on a support, thereby showing an excellent activity and preparing a polyolefin having a high molecular weight.

A system for precision polymerization is disclosed comprising at least one Michael-type monomer and a metal compound MR.sup.1R.sup.2R.sup.3 as sole catalyst and initiator, wherein M is aluminum, gallium or indium, each of R.sup.1, R.sup.2, and R.sup.3 independently is CI, F, I, Br, linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkenyl, linear, branched, or cyclic alkinyl, heterocycloalkinyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, nitro, nitroso, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkinyl or alkoxy group independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from the group consisting of O, S, and N, wherein each alkyl, alkenyl, alkinyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkinyl, aryl, heteroaryl, aryloxy group can be substituted by 1 up to the highest possible number of halogen atoms, or at least one electron-donating or electron-withdrawing group; with the proviso that not all three groups R.sup.1, R.sup.2, and R.sup.3 are halogen, hydroxy, or alkoxy or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic or heterocyclic group having 3 to 6 atoms, wherein a heterocyclic group has at least one hetero atom selected from the group consisting of O, S, and N; as well as processes for preparing polymers and the polymers obtained therewith.

The present invention involves a radical polymerization initiator comprising an organotellurium compound represented by a formula (1), wherein R.sup.1 represents an alkyl group or the like, each of R.sup.2 and R.sup.3 independently represents a hydrogen atom or the like, and each of R.sup.4, R.sup.5, and R.sup.6 independently represents a hydrogen atom or the like.

The present invention provides: a radical polymerization initiator that is useful for producing a polymer that includes a double bond at the molecular terminal; and a method for producing a polymer that utilizes the radical polymerization initiator.

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