Abstract:
Polyoxymethylene compositions with polyoxymethylene polymers polymer/polyol additives having a core-link-arm structure. Upon molding, these compositions exhibit stable melt viscosity and simultaneous improvement in notched Izod impact strength and/or decreased relative apparent capillary melt viscosity, and/or increased elongation at break, relative to polyoxymethylene compositions lacking such core-link-arm structure additives.
Abstract:
Novel polyglycerol aldehyde polymers are described. The polymers comprise glycerol monomers connected by ether linkages and have 3 to about 170 aldehyde groups per molecule. The polyglycerol aldehydes may be reacted with various amine-containing polymers to form hydrogel tissue adhesives and sealants that may be useful for medical applications such as wound closure, supplementing or replacing sutures or staples in internal surgical procedures such as intestinal anastomosis and vascular anastomosis, tissue repair, preventing leakage of fluids such as blood, bile, gastrointestinal fluid and cerebrospinal fluid, ophthalmic procedures, drug delivery, and preventing post-surgical adhesions.
Abstract:
Processes for preparing crosslinked polymers using biomass derived materials, such as aldaric acids and derivatives, are provided. The polymers can be used as hydrogels.
Abstract:
An embodiment of the invention is a water soluble chain-extended polyamine product made by a process comprising reacting a multi-arm polyether amine with a bifunctional crosslinker of the formula: X1—R—X2. Another embodiment is a water soluble chain-extended polyamine product made by a process comprising reacting a multi-arm polyether having at least three arms and three electrophilic endgroups with a primary diamine crosslinker of the formula: NH2—R2—NH2, followed by treating of the chain-extended product so as to convert the remaining electrophilic endgroups to amine endgroups. Crosslinking of the chain-extended polyamine products with an oxidized polysaccharide provides useful tissue adhesives with modified elasticity, that provides greater compliance to underlying tissue, and improved stability in aqueous environments.
Abstract:
A tissue adhesives and sealant formed by reacting a polyglycerol aldehyde with a water-dispersible, multi-arm amine is described. The tissue adhesive and sealant may be useful for medical and veterinary applications, including, but not limited to, wound closure, supplementing or replacing sutures or staples in internal surgical procedures such as intestinal anastomosis and vascular anastomosis, tissue repair, preventing leakage of fluids such as blood, bile, gastrointestinal fluid and cerebrospinal fluid, ophthalmic procedures, drug delivery, and to prevent post-surgical adhesions.
Abstract:
A process is provided to improve the specific activity of an enzyme catalyst having nitrilase activity when converting glycolonitrile to glycolic acid under aqueous reaction conditions. Inclusion of an effective amount of at least one amine protectant improves the specific activity and catalytic productivity of the enzyme catalyst.
Abstract:
A process is provided to improve the specific activity of an enzyme catalyst having nitrilase activity when converting glycolonitrile to glycolic acid under aqueous reaction conditions. Inclusion of an effective amount of at least one amine protectant improves the specific activity and catalytic productivity of the enzyme catalyst.
Abstract:
Processes using alpha, omega-difunctional aldaramides as monomers and crosslinkers are disclosed. The processes can be used to form polymers, particularly crosslinked polymers.
Abstract:
Alpha, omega-difunctional aldaramides, in particular diaminoaldaramides, dihydroxyaldaramides, bis(alkoxycarbonylalkyl)aldaramides, and bis(carboxyalkyl)aldaramides, and processes for preparing the aldaramides are provided.
Abstract:
Polyoxymethylene compositions with polyoxymethylene polymers polymer/polyol additives having a core-link-arm structure. Upon molding, these compositions exhibit stable melt viscosity and simultaneous improvement in notched Izod impact strength and/or decreased relative apparent capillary melt viscosity, and/or increased elongation at break, relative to polyoxymethylene compositions lacking such core-link-arm structure additives.