Manipulation of the thermal/mechanical properties of the fiber/polymer interface in PA6/epoxy composite via uniform/un-uniform colloidal stamping of silica/hollow graphene oxide nanoparticles

• Published in: Colloid and polymer science Vol. 300; no. 12; pp. 1389 - 1404
• Main Authors: Rashidi, Omid, Sharifzadeh, Esmail
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2022; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Coated fibers; Colloiding; Complex Fluids and Microfluidics; Dynamic mechanical analysis; Epoxy resins; Food Science; Graphene; Mechanical properties; Nanoparticles; Nanotechnology and Microengineering; Original Contribution; Physical Chemistry; Polymer Sciences; Polymers; Silicon dioxide; Soft and Granular Matter; Stamping; Polymer composites; Interphase; Interface; Stamping process; Thermal/mechanical analysis
• ISSN: 0303-402X; 1435-1536
• DOI: 10.1007/s00396-022-05030-9

In this study, the effect of randomly oriented high modulus PA6 fibers on the thermal/mechanical properties of epoxy resin was investigated based on the characteristics of the polymer/fiber interface. Accordingly, it was tried to use a novel colloidal stamping process to manipulate the characteristics of the interface using silica and hollow graphene (HO) nanoparticles. The process was conducted based on two different strategies: (i) uniform (simple) and (ii) un-uniform (Janus) stamping processes. In the first strategy, the stamping process on the upper and lower side of the fibers was performed using only one type of nanoparticles, while the second method involved stamping different nanoparticles on different sides of the fibers. The prepared coated fibers (1–3 wt.%) were then added to the epoxy matrix, and the samples were subjected to the dynamic mechanical analysis (DMTA), thermal conduction, FE-SEM, and light-microscopy tests. Moreover, other samples containing uncoated PA6 fibers and/or silica/HO nanoparticles were prepared and evaluated using the aforementioned tests to provide a better insight into the effect of each component. A new thermal/mechanical model was also proposed to interpret the characteristics of the polymer/fiber interface using DMTA and thermal conduction test results. Accordingly, it was found that a neat PA6/epoxy interface negatively affected the thermal/mechanical properties of the system while adding up to 3 wt.% of each uniformly or un-uniformly coated PA6 fiber substantially increased the final modulus and thermal conduction coefficient of the system.