Abstract:
Embodiments of the polymerization process of the present invention are directed to polymerizing free radically polymerizable monomers in the presence of a polymerization medium initially comprising at least one transition metal catalyst and an atom transfer radical polymerization initiator. The polymerization medium may additionally comprise a reducing agent. The reducing agent may be added initially or during the polymerization process in a continuous or intermittent manner. The polymerization process may further comprise reacting the reducing agent with at least one of the transition metal catalyst in an oxidized state and a compound comprising a radically transferable atom or group to form a compound that does not participate significantly in control of the polymerization process. Embodiments of the present invention comprise reacting a reducing agent with at least one of catalyst in an oxidized state and a compound comprising a radically transferable atom or group to initiate and/or maintain catalytic activity throughout the polymerization process.
Abstract:
Embodiments of the polymerization process of the present invention are directed to polymerizing free radically polymerizable monomers in the presence of a polymerization medium initially comprising at least one transition metal catalyst and an atom transfer radical polymerization initiator. The polymerization medium may additionally comprise a reducing agent. The reducing agent may be added initially or during the polymerization process in a continuous or intermittent manner. The polymerization process may further comprise reacting the reducing agent with at least one of the transition metal catalyst in an oxidized state and a compound comprising a radically transferable atom or group to form a compound that does not participate significantly in control of the polymerization process. Embodiments of the present invention comprise reacting a reducing agent with at least one of catalyst in an oxidized state and a compound comprising a radically transferable atom or group to initiate and/or maintain catalytic activity throughout the polymerization process.
Abstract:
Polymers comprising a polymer backbone comprising one or more degradable units are described. The polymer may additionally comprise two or more polymer segments comprising radically (co)polymerizable vinyl monomer units. The degradable units may be independently selected from, but not limited to, at least one of hydrodegradable, photodegradable and biodegradable units between the polymer segments and dispersed along the polymer backbone. The degradable units may be derived from one or more monomers comprising a heterocyclic ring that is capable of undergoing radical ring opening polymerization, a coupling agent, or from a polymerization initiator, radically polymerizable monomers, as well as other reactive sources. Embodiments of the degradable polymer of claim are capable of degrading by at least one of a hydrodegradation, photodegradation or biodegradation mechanisms to form at least one of telechelic oligomer and telechelic polymeric fragments of the polymer. The degradable polymer may be able to degrade into polymer fragments having a molecular weight distribution of less than 5, or in certain applications it may be preferable for embodiments of the polymer to be capable of forming polymer fragments having a molecular weight distribution of the polymer fragments less than 3.0 or even less than 2.5. Embodiments of the present invention also include methods of producing degradable polymers.
Abstract:
Described herein are amide and/or imide containing polymers based on novel monomers that contain isoalkylidene bridges. These polymers have excellent toughness combined with high temperature stability, low water absorption, and good melt-fabricability.
Abstract:
A polymer composition comprising star macromolecules is provided. Each star macromolecule has a core and five or more arms, wherein the number of arms within a star macromolecule varies across the composition of star molecules. The arms on a star are covalently attached to the core of the star; each arm comprises one or more (co)polymer segments; and at least one arm and/or at least one segment exhibits a different solubility from at least one other arm or one other segment, respectively, in a reference liquid of interest.
Abstract:
Described herein are amide and/or imide containing polymers based on novel monomers that contain isoalkylidene bridges. These polymers have excellent toughness combined with high temperature stability, low water absorption, and good melt-fabricability.
Abstract:
Aryl arylate esters substituted with an acyl moiety on both the aryl and arylate groups of said esters which can be produced by the oxidation of alkyl substituted aryl arylate esters using a heavy metal/bromine catalyst.
Abstract:
Color stable compositions consisting of aromatic polyester and 0.01 to 0.5% by weight of the aromatic polyester of a stabilizer selected from the group consisting of phosphates, phosphonates and mixtures of either phosphates or phosphonates with epoxides having a boiling point of above about 250.degree. C. These compositions are useful in the manufacture of engineering plastics such as automobile headlights.
Abstract:
A fire retardant polymer which has a low halogen content is obtained by incorporating a vinyl aromatic containing a group reactive under Friedel-Crafts conditions and a Lewis acid or Lewis acid precursor within a thermoplastic composition.
Abstract:
Addition of very small amounts of bromine or bromine-containing compounds in the preparation of rubber-modified vinyl aromatic polymers increase their impact resistance.