Doctoral Dissertations


"The major cost drivers for composites are raw materials and manufacturing process. Automated manufacturing processes like pultrusion and low cost bio-based raw materials can significantly lower the cost of composites. Polyurethane (PU) resin systems are being introduced in the pultrusion industry as they have higher performance characteristics and manufacturing feasibility when compared to conventional resin systems such as polyester and vinyl ester. PU resin systems are generally characterized as aromatic and aliphatic. Aliphatic PU has lower mechanical properties than the aromatic resin system due to its chemical structure. Nano materials can be used to increase the mechanical properties of aliphatic PU resin. In Paper 1, glass fiber reinforced PU pultruded panels have been manufactured using the base PU and the soy-based PU resin systems. Soy-based PU resin systems showed comparable properties to that of the base PU resin system and is a viable alternative to the conventional petroleum based PU. In Paper 2, commercially available sodium montmorillonite (Na-MMT) clay was modified with methyl triethanolammonium salt using ion exchange process to make it compatible with the PU resin system. Nanocomposites were synthesized using the PU resin systems, Na-MMT and modified MMT clay. Modification ofNa-MMT was confirmed by Fourier transform infrared spectroscopy, Thermogravimetric analysis and X-ray photoelectron spectroscopy. Tensile testing of the nanocomposites showed improved mechanical properties when compared to the neat aliphatic resin system. Soy-based PU nanocomposites hold great promise as environmentally friendly and low cost materials for structural and automotive applications"--Abstract, page iv.


Chandrashekhara, K.
Schuman, Thomas P.

Committee Member(s)

Dharani, Lokeswarappa R.
Birman, V. (Victor)
Showalter, William E.


Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering


United Soybean Board
Missouri University of Science and Technology. Department of Mechanical and Aerospace Engineering
Missouri University of Science and Technology. National University Transportation Center


Missouri University of Science and Technology

Publication Date


Journal article titles appearing in thesis/dissertation

  • Manufacturing and impact characterization of soy-based polyurethane pultruded composites
  • Synthesis and performance evaluation of soy-based aliphatic polyurethane nanocomposites


ix, 59 pages

Note about bibliography

Includes bibliographical references.


© 2012 Rama Bhadra Raju Vuppalapati, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type




Subject Headings

Polymeric composites -- Industrial applications
Polymeric composites -- Mechanical properties
Soy oil -- Research

Thesis Number

T 10568

Print OCLC #


Electronic OCLC #


Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

Share My Dissertation If you are the author of this work and would like to grant permission to make it openly accessible to all, please click the button above.