Abstract
In this work, the effect of curing agent, curing conditions and the incorporation of small amounts of organoclay on the thermal properties of DGEBA (diglycidyl ether of bisphenol A) epoxy resin was evaluated in order to develop an epoxy system for application as the matrix in active composites whose dispersed phase consists of shape memory alloy wires. The DGEBA resin was prepared using three amine derivatives as hardeners (triethylenetetramine - TETA, diethylenetriamine - DETA and diaminodiphenylsulfone - DDS) under varied curing conditions, in the absence and presence of organoclay. Epoxy systems were characterized by dynamic mechanical analysis (DMA), optical microscopy and X-ray diffraction. According to the obtained results, the cured DETA and DDS epoxy systems at elevated temperatures, above 180°C, showed a higher glass transition temperature (Tg) and thermal stability values than the system cured at low temperature (TETA). In addition, when the post-cure treatment was used, an improvement of the thermal stability was verified. When 1 phr (parts hundred resin) of organoclay was incorporated in DETA and DDS cured epoxy systems and post-cured, either the increase in the Tg and thermal stability values were more significant, especially for the system cured with DDS. Hence, the epoxy/DDS/organoclay system (exfoliated nanocomposite) is the most appropriate to be used as the matrix in the preparation of active composites since this matrix is thermally stable in the Ni-Ti shape memory alloy working range whose phase transformation occurs between 70 and 80 °C.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
