Characterization of polybutene modified denture acrylics

Summary form only received as follows: The objective of this study was to evaluate the use of a polybutene additive to improve the flexure strength of cold cured acrylic systems. Three different number average molecular weight polybutenes were used including H100 (920 g/mole), L65 (610 g/mole) and L14 (320 g/mole) (Amoco Chemical Co.). The polybutenes were blended at 0, 1, 5 and 10 weight % with a cold cure acrylic system and compression molded into rectangular specimens 13 mm wide x 3 mm thick x 28 mm long. Ten specimens were prepared for each formulation and stored for seven days in distilled water at 37/spl deg/C before flexure testing. A three point flexure test was run using a span of 20 mm at a rate of 1 mm/minute. The results for the cold cure acrylic are given. The only polybutene formulation which improved the flexure strength was the 1% H100 composition. Although the 1% H100 formulations did improve the flexure strength of the acrylic, the change was not statistically significant when compared using a t-test (p <.05). Incorporation of polybutenes did not significantly improve the flexure strength of dental acrylics tested in this study.