Resin film infusion: Toward structural composites with nanofillers

Abstract

Resin Film Infusion (RFI) has been used to fabricate composites with continuous unidirectional E-glass and epoxy with low weight fractions of carbon nanotubes (CNTs) in matrix. An ultrasound-assisted dissolution-evaporation method with thermoplastics or block copolymers as dispersing agents for nanoparticles enabled uniform dispersion of CNTs in the resin. Rheological characterization of CNT-filled epoxy revealed that viscosity, and hence processing of the resin remains unaffected as compared to pristine resin at elevated temperatures of subsequent composite manufacturing. Local flow of the modified resin through the sandwiched fabric plies in RFI process as against the global flow in traditional liquid composite molding processes, made sure that uniform distribution of nanoparticles is accomplished throughout the composite. Compressive properties of hybrid composites improved considerably with CNTs at loading fractions as low as 0.2 wt %.

Experimental study of the rheological, mechanical, and dielectric properties of MgO/LDPE nanocomposites

“…Viscosity, representing the flow ability of a viscous liquid, was emphasized for the rheological study of MgO/LDPE PNCs melts. In common sense, the immiscibility between the matrix and the nano‐inclusions usually causes the so‐called rheological degradation, i.e., dramatically increasing the viscosity . For seeking the viscosity percolation threshold, special attention was given to those MgO/LDPE PNCs with low amount of MgO‐NPs.…”

“…Viscosity reduction, however, was also reported in Jain's work when a very small amount of silica‐NPs were introduced into polypropylene matrix. NPs with higher aspect ratio and larger surface area as well as good compatibility with matrix resulted in higher interfacial strength and better mechanical performance, but higher melt viscosity was also revealed …”

Mechanical properties of hybrid structural composites reinforced with nanosilica

“…Curing takes place with subsequent heating to 120°C and soaking for 60 min. After completing the heating cycle, oven is switched off and the job is allowed to cool slowly to room temperature before demolding . Schematic of the RFI process is shown in Fig.…”

“…None of these methods are compatible to be processed with polymer resins, which are premodified with nanoparticles. Although properly dispersed nanofillers in polymer matrices have been demonstrated as an extremely effective method for improving the performance of polymer composites, resin film infusion (RFI) is the only viable method favoring an alteration of rheological aspects of the matrix polymer toward realizing hybrid fiber reinforced composites . With a unique recipe of diglycidyl ether of bisphenol A (DGEBA) based epoxies developed in‐house, which apparently maintains a semisolid consistency at ambient and flows at elevated temperatures, this technique offers an excellent alternative for the above‐mentioned conventional fabrication methods.…”

Improvement of the Impact Properties of Composite Laminates by Means of Nano-Modification of the Matrix—A Review

“…In this method, the nanofibers were firstly electrospun on dry glass fibers, then cast resin film was transferred to them. The method is called RFI and more details about it can be found in [31]. They conducted impact and CAI tests, but only the results of the second test were reported.…”