Synergetic behavior of low T_g polybutadiene polymers and polysiloxanes as components for glass fiber sizing in composite materials

Abstract

The effect of low T g polybutadiene (PBD) rubbery polymer as a part of polysiloxane/PBD E-glass fibers sizing on mechanical properties of a corresponding epoxy composite material has been evaluated by the punch shear test technique. The results show that the use of hydroxyl terminated PBD led to significant increase in interface shear strength, energy absorption, as well as dynamic modulus and T g in a corresponding composite material. The sizing composition and fiber morphology were characterized by FTIR spectroscopy and AFM microscopy, respectively. Possible rational for such sizing composition/material property relationship is discussed.

Affecting glass fibre surfaces and composite properties by two stage sizing application

“…As there is a steadily increasing interest in the use of thermoplastic composites in different fields, such as construction, automotive industries and aeronautic industries, in the field of GF reinforced thermoplastic composites various strategies have been developed in order to tailor the interphase characteristics, which mainly focused on the modification of GF surface or matrix, aiming at enhancing the GF-matrix adhesion strength, such as by enhancing GF-matrix compatibility, mechanical interlocking, and acid-base interaction [1][2][3][12][13][14]. From the viewpoint of production, on-line surface modification of the as-spun GF with an appro-priate sizing (generally a mixture of silane coupling agent, polymeric film former and additives) is a straightforward strategy for tailoring the interphase properties to give cost-effective composite materials [14][15][16][17][18][19][20][21][22][23][24][25]. Thus, great attentions have been paid on the sizing structure or radial chemical composition to deepen the understanding of the correlation between the mechanical properties of composites and both the sizing and sizing technology.…”

Improvement in interfacial shear strength and fracture toughness for carbon fiber reinforced epoxy composite by fiber sizing

“…Several methods have been studied to improve the fracture toughness of composites, such as modifying thermosets with ductile thermoplastics and rubber, incorporating different fibers in a matrix material to form a hybrid fiber composite, using of large diameter fibers, coating fibers intermittently with an appropriate fluid before the fibers incorporate into the matrix, interleaving a tough strip between plies of laminated composites, reduction of matrix shrinkage stress, and coating fibers with an appropriate polymer . Because of the simplicity in application to practical composites and feasibility of direct comparison of fracture behavior between composites with uncoated and coated fibers, fiber coating techniques have received most attention from researchers amongst the various toughening methods . The principal effect of altering interfacial bond strength by fiber coating is to modify the mode of failure and thus the potential energy absorbing capacity which in turn determines the fracture toughness of a composite.…”