Effects of Graphene on Mechanical Behavior of Polymers Reinforced with Flax Fibers Effected by Environmental Conditioning

Open Access
Author:
Cook, Tyler Jonathan
Area of Honors:
Mechanical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Richard Christopher Ciocci, Thesis Supervisor
  • Ronald Walker, Honors Advisor
  • Amit Banerjee, Faculty Reader
Keywords:
  • graphene
  • long-term mechanical properties
  • flax reinforced composites
  • environmental conditioning
Abstract:
Fiber reinforced composites (FRCs) are important materials in industries where weight plays a limiting factor because FRCs have high strength to weight ratios. Graphene is a relatively new material which has been studied for its promising effects on the mechanical properties of reinforced composites. Additionally, flax fibers are of interest in the composite industry for their sustainability and bio-renewability. This paper examines the effects of graphene additives at 0.125 wt. % of polymer and polymer-flax composites and how graphene alters the long-term mechanical properties of samples exposed to environmental conditioning. Samples include polymer, polymer-graphene, polymer-flax, and polymer-flax-graphene. Specimens were conditioned in water at 22 and 60 °C for 3 and 6 weeks. The samples, including control, were then subject to a postconditioning oven dry for 24 h at 60 °C. Graphene introduction appears to have reduced water absorption with respect to change in mass before and after environmental conditioning. Based on tensile data of ultimate tensile strength and Young’s modulus, graphene was not evenly dispersed throughout the epoxy matrix as evident by a decrease in tensile properties of control samples including graphene vs. those control samples without. Some of the results were promising; however, to limit graphene agglomeration, further steps need to be taken including the use of surfactants, selecting a different polymer matrix, and/or using an ultrasonic mixing technique.