Poly(propylene oxide) Modified Dimethacrylate Networks

ABSTRACT

A series of methacrylated poly(propylene oxide)/reduced styrene content/dimethacrylate resin systems have been prepared. These modified vinyl esters may be ideal for coatings, toughened matrix resins for fiber-reinforced composites, bridge deck wear surface resins, and structural adhesive applications. Network systems cured with room-temperature and elevated-temperature cure methods have been studied. The network morphologies were investigated by DMA and TEM analyses. The K_1c values of the adhesives increases when systems were cured with the room-temperature cure package. The lap-shear strength of these systems were investigated for structures including composite-to-composite, composite-to-steel, and composite-to-concrete following ASTM D1002. Lap-shear adhesive strengths of all of the adhesives, which had appropriate viscosities on composite substrates, were in the structural regime with values of ∼13.8 MPa. Room-temperature cure schedules (with and without a postcure) resulted in good adhesive strength on the composite and aluminum substrates, displaying values up to 15.2 MPa.

Keywords:

• Modified dimethacrylate resins
• Poly(propylene oxide)
• Reduced volatile content
• Free radically cured networks
• Fiber-reinforced polymer composite substrate
• Structural adhesive

ACKNOWLEDGMENTS

The authors thank the National Science Foundation Science under contract number DMR-9120004 and the Center for Adhesive and Sealant Science at Virginia Tech for funding, and Dow Chemical, Bayer Corporation, and Witco Corporation for donation of materials.