The University of Akron

Covestro LLC

Other

Robert A Weiss

Matthew L Becker

Karl W Haider

Don S Wardius

Zachary Kurtiss Zander

Bruce D Lawrey

Ying Shi

Mitra Yoonesi

In one or more embodiments, the present invention provides a novel approach to the addition of plasticizers for softening TPUs, i.e., lowering the durometer and the melt viscosity. This approach involves incorporating bonded sulfonate groups with quaternary ammonium counterions into the TPU. In one or more embodiments of the present invention, the softening of TPU is achieved by incorporating an ionic diol, such as N,N-bis (2-hydroxyethyl)-2-aminoethane-sulfonic acid (BES), coupled with various bulky alkyl ammonium cations, during the chain extension step of the TPU synthesis. It is believed that that steric hindrance of the bulky quaternary ammonium groups weakens the dipole-dipole interactions of the sulfonate groups and/or lowers the crystallinity of the hard block, thereby creating additional free volume that softens the polymer and lowers the melt viscosity.

Softening thermoplastic polyurethanes using ionomer technology

In one or more embodiments, the present invention provides a novel approach to the addition of plasticizers for softening TPUs, i.e., lowering the durometer and the melt viscosity. This approach involves incorporating bonded sulfonate groups with quaternary ammonium counterions into the TPU. In one or more embodiments of the present invention, the softening of TPU is achieved by incorporating an ionic diol, such as N,N-bis (2-hydoxyethyl)-2-aminoethane-sulfonic acid (BES), coupled with various bulky alkyl ammonium cations, during the chain extension step of the TPU synthesis. It is believed that that steric hindrance of the bulky quaternary ammonium groups weakens the dipole-dipole interactions of the sulfonate groups and/or lowers the crystallinity of the hard block, thereby creating additional free volume that softens the polymer and lowers the melt viscosity.

The present invention is directed to a covalently crosslinked hydrogel comprising the strain-promoted reaction product of an 8-member cycloalkyne functionalized polyalkylene glycol and a multi-arm glycerol exytholate triazide and methods for making them. Because the precursor materials can be manipulated without causing crosslinking, provided the strain threshold is not reached, these hydrogels permit mechanical control over when (and where) cross linking occurs and are easier to use than prior strain-activated or temperature-activated systems. These novel hydrogels do not require a catalyst to cross link, thus avoiding the biocompatibility problems common to many catalysts. Nor is the crosslinking process affected by the presence of catalysts or other substances, which have interfered with crosslinking in known strain induced hydrogels. Because of their crosslinking reaction kinetics, these novel hydrogels can encapsulate and transport highly sensitive cells and other biological additives and have no known toxic byproducts.

Strain-promoted crosslinking of PEG-based hydrogels via copper-free cycloaddition

A shape memory composition includes a high temperature ionomer having a glass transition temperature or a melting temperature of 100&#xb0; C. or greater and a modulus at room temperature of 1&#xd7;10Pa or greater, the high temperature ionomer including a polymer with ionic units either within the backbone of the polymer or pendant to the backbone or both. The shape memory composition includes crystalline or glassy domains of a low molecular weight non-polymeric compound dispersed in the high temperature ionomer and interacting the ionic units of the high temperature ionomer to form a secondary network characterized by being a reversible network in that it is compromised by the heating of the low molecular weight non-polymeric compound to change out of its crystalline or glassy phase.

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Akron, OH, United States of America

Robert A Weiss