Discipline: Technology and Engineering
Subcategory: Materials Science
Shatori Meadows - Tuskegee University
Co-Author(s): Mahesh Hosur and Shaik Jeelani, Tuskegee University, Tuskegee, AL
Cure kinetics is appropriate for determining the cure conditions as a result of temperature and time in thermoset resins. This theory is especially significant in manufacturing processes such as pultrusion, where the current process mainly uses unsaturated polyester resins. These unsaturated polyester resins offer certain advantages compared to other thermosetting matrices that include low cost, good mechanical and chemical properties, and good weather resistance. However, many unsaturated polyester resins are produced from petroleum based by-products, as synthetic polymers. Moving away from these synthetic resins that affect the earth’s atmosphere is a demanding change necessary in today’s society. Hence, effects of five different peroxide initiators on the cure behavior and thermal properties of recycled unsaturated polyester resins was studied using Envirez™ 50380 resin provided by Ashland Incorporated. The peroxide initiators used in the study were Benzoyl peroxide (BPO), Methyl Ethyl Ketone Peroxide (MEKP), Tert-butylperoxy benzoate (TBPB), Luperox® CU80 and Luperox® IS-300 measured at one part per hundred for initiation of polymerization process during curing. This research emphasizes the importance of controlling the cure reaction kinetics for potential use in various fabrication processes. Controlling the initiated system would aid in energy savings, lightweight materials, improve mechanical properties, and consequently cost savings that provide societal benefit. Reaction kinetics was studied using differential scanning calorimetry (DSC) under dynamic and isothermal regimens and analyzed using Kissinger, Friedman, and Kamal models of kinetic analysis. Kinetic parameters such as activation energy, reaction rate constants and orders were determined from the results and used in selecting the most suitable controlled initiator for each resin. Results from this study indicated lower activation energy for MEKP and BPO compared to the other initiators when using Kissinger, Friedman, and Kamal models. TBPB showed one of the highest activation energy with a narrow exothermic peak. The narrow peak in TBPB is an indication of fast reaction kinetics, confirmed by reaction rate constants. On the other hand, broad peak for MEKP indicates a more controlled rate of curing for possible use in other fabrication processes. Future work would involve determining the gel-time and minimum viscosity of each initiated system to aid in further processing conditions.Shatori Meadows ERN Abstract -2016.docx
Funder Acknowledgement(s): NSF-EPSCoR; NSF-CREST; Alabama Commission of Higher Education (ACHE).
Faculty Advisor: Mahesh Hosur, firstname.lastname@example.org