Processing and Characterization of Bismaleimide Composites Modified with Core-Shell Siloxane (CSS)/Carbon Nanotubes (CNTs)

Graduate #109
Discipline: Technology and Engineering
Subcategory: Materials Science

Chukwuma Nweke - Tuskegee University

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In this work, an economical out-of-autoclave processing method was developed to prepare bismaleimide, BMI-1 composites. In addition, BMI-1 resin was modified with hydroxyl functionalized carbon nanotubes (CNTs) and core-shell siloxane to optimize the mechanical, viscoelastic and thermal properties. 3-point bend test, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) were conducted. The addition of CSS lead to decrease in flexural and viscoelastic properties in comparison to neat BMI-1 samples. However, the BMI-1/CNTs samples showed significant improvement in these properties with a optimum at 0.15wt. % loading. Further increase in CNT wt. % loading showed a declining trend in these properties which can be attributed to poor dispersion of CNTs. Scanning electron micrographs of fractured specimens showed rougher fracture surface in 0.15 wt. % CNT samples indicating the high resistance offered by the material prior to failure. In contrast, crack was found to initiate from a localized region in 0.5 wt. % CNTs samples which may be the remains of poorly dispersed CNTs. Agglomerated CNTs in polymers acts as precursor to crack formation causing premature failure. A smoother fracture surface was observed in both neat BMI-1 and BMI-1/CSS samples.

Not Submitted

Funder Acknowledgement(s): This research work is supported by the AFRL, NSF-EPSCoR.

Faculty Advisor: Shaik Zainuddin, szainuddin@mytu.tuskegee.edu