Morphological and mechanical behavior of polyurethane/epoxy interpenetrating polymers and its flax fiber‐reinforced composites

Abstract

The application of plant fiber-reinforced epoxy plastic is severely limited by its relatively low mechanical properties, especially for its brittleness and weak interlaminar properties. The physical and mechanical properties in both nanoand macro-scales of polyurethane/epoxy interpenetration networks were deeply investigated through dynamic mechanical analysis, atomic force microscope and the tensile tests. The atomic force microscope analysis shows that proper amount of polyurethane and evenly distribution could improve the mechanical properties of the resin cast due to the polyurethane/epoxy interpenetrating networks fix the phase zone and increases the strength and stiffness of the system and this was proven with macroscale tensile tests. Moreover, it is impressive to notice that with addition of 15 wt% of polyurethane into epoxy, the initial fracture toughness of its corresponding composite exhibits 48% enhancement. The results in this study indicate that polyurethane/epoxy interpenetration networks show positive effect on improving the interfacial and interlaminar properties of plant fiber reinforced composites. K E Y W O R D S dynamic mechanical properties, interlaminar fracture toughness, interpenetrating polymer network, nanomechanical properties, plant fiber-reinforced plastic

The synergistic impacts of hybrid nanofillers of graphene nanoplatelets/carbon nanotubes on curing behavior of an epoxy‐vinyl ester interpenetrating polymer network nanocomposite coating

“…[1][2][3][4][5] Interpenetrating polymer networks (IPNs), among the different types of polymeric mixtures, are a specific group of hybrid polymer materials comprising two thermosetting resins in which the polymer networks are physically and permanently linked together via chain entanglements, as well as chemically a few bond formations between two resins. [6][7][8][9][10][11][12] Thermosetting resins similar to vinyl ester, polyester, and especially epoxy are generally applied as coating binders. 13,14 The epoxy-vinyl ester blend can form IPNs consisting of two cured resins, the interlaced networks forming one homogeneous system on a molecular scale.…”

“…The mechanical and chemical combination techniques and features of multiple polymers are of great industrial and academic significance for coating performances because they provide a useful method for modifying properties to achieve the specified application 1–5 . Interpenetrating polymer networks (IPNs), among the different types of polymeric mixtures, are a specific group of hybrid polymer materials comprising two thermosetting resins in which the polymer networks are physically and permanently linked together via chain entanglements, as well as chemically a few bond formations between two resins 6–12 . Thermosetting resins similar to vinyl ester, polyester, and especially epoxy are generally applied as coating binders 13,14 .…”

Glycidyl Carbamate Resins Synthesized through a Nonphosgene Route by Amidine-Based Superbases Using Recycled Polycarbonate

“…In addition, only limited amounts can be added, because of their poor dispersion in the epoxy resin matrix. An alternative solution is to copolymerize epoxy resins through the incorporation of flexible polymers, such as acrylic melamine, polyaniline, and PU , to enhance the toughness and mechanical durability of the cured epoxy resins. In one example, GC resins are the glycidyl carbamate functional resins that consist of an epoxide adjacent to a carbamate functional group .…”

Study on Axial Compression Behavior of Concrete Short Columns Confined by Flax/Glass Fiber Hybrid-Reinforced Epoxy Resin Composites

“…In recent years, composite materials consisting of natural plant fibers, such as flax, jute, ramie, hemp, etc., have attracted the attention of researchers in various fields. They have the advantages of being lightweight, high-strength, degradable, economic, practical, and providing environmental protection, and they meet the needs of the current international development trend [ 14 , 15 , 16 ]. Among these composites, the tensile strength and stiffness of flax fiber can be up to 1500 MPa and 90 GPa, respectively, with low density (1.5 g/cm 3 ) and good low-cost characteristics [ 17 , 18 , 19 ].…”