Polymeric glasses mechanical properties

A sample of polymer B prepared by using sodium methoxlde as an additive had a nsp of 0.5 and a of 46,000 (9). The glass transition temperature was between 4 and 10°C and the crystalline melting point was between 140 and 160°C. The specific gravities of monomer II and polymer B are respectively 1.528 and 1.483 this would indicate an expansion upon polymerization. The mechanical properties of this sample of polymer B are shown in Table II (16). 

Linear polyethylene (hdpe), which has a repeating unit of 4-CHr CH24 , is a typical thermoplastic with a glass transition temperature Tt below room temperature. Its mechanical properties permit its use as both a plastic and a fiber. From a structural viewpoint, this polymeric hydrocarbon is the least complex of all polymers. 

The step 1 product combined with ophthalmic agents and 2,2 -azobis(2-methylpropio-nitrile) was clamped between two silanized glass plates and polymerized by heating to 100°C for 2 hours. The film was isolated and hydrated in deionized water for at least 4 hours and then autoclaved for 30 minutes at 121°C. The cooled films were analyzed for mechanical properties according to ASTM D-1708a and oxygen permeability. 

Foams with polymeric microspheres have poor mechanical properties because the filler and binder have similar elasticities. Consequently the binder s strength is not reflected as clearly as it is when glass spheres are used. 

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