Typical hydro gels lack the required mechanical properties to be useful as articulating and weight bearing materials.  Therefore, new hydro gels were developed which incorporated both a hydrophilic and a hydrophobic segment.  These new hydro gels behave like semi-crystalline polymers utilizing both crystalline regions and amorphous regions.  The hydrophilic segments (amorphous regions) provide the water absorption, fluid flow, and lubricious properties.  The hydrophobic segments (crystalline regions) provide the strength, tear, and shear resistance.  Properties can be varied based off of the ratio of hydrophobic to hydrophilic composition. 
     The focus of this study was to develop a hydro gel material with higher strength as compared to standard hydro gels and allowed for ease of processing.  Initial efforts focused on utilizing polymer blends with cross-over into reactive compounding.  The blended materials were initially based on vinyl alcohol as the hydrophilic segment and ethylene, styrene, or poly(hexamethylene phthalate) as the hydrophobic segment.  To create a melt processable miscible blend, the polymers were processed in dimethyl sulfoxide/water (80%/20%) mixture between 80-160°C to form a lyogel.  Blend ratios above 30% were processed in either a sigma mixer or a twin screw extruder.  The materials showed a uniform glass transition temperature and no crystalline domains.  Materials were pellettized after processing and injection molded as the lyogel. After processing, materials were exchanged in alcohol for a minimum of 20 minutes followed by immersion in water.  During the exchange process, the materials turned from a transparent to an opaque, flexible hydro gel as the crystal domains formed.  The phase separated hydro gels showed increases in tensile/tear strength, young’s modulus, and percent elongation at break as compared to PVA homopolymers