Development of eco-friendly brake friction composites containing flax fibers

Abstract

Eco-friendly brake friction composites with good friction performance were developed. The raw materials utilized were selected according to eco-friendly criterion that natural products should be preferably chosen. The formulations are composed of plant flax fiber, mineral basalt fiber, and wollastonite as reinforcements, natural graphite as solid lubricant, zircon as abrasive, vermiculite and baryte as functional and space fillers, and cardanol-based benzoxazine-toughened phenolic resin as binder. To isolate the flax fibers, chemical and physical methods including drying, room temperature alkaline solution, and acid steam treatment were performed and fibers with micro-fibrillated structure on the surface were formed. A new cardanol-based benzoxazine synthesized by the reactions among cardanol, aniline, and formaldehyde was used as toughening for phenolic resin. The effects of both the content of treated flax fibers and friction temperature on friction performance, friction coefficient and specific wear rate, of the friction composites were evaluated by the extension evaluation method.

Overview of disc brakes and related phenomena - a review

“…Asbestos fibres were widely used as reinforcing material but has been replaced with other materials due to environmental problems connected to asbestos [41]. Other materials used as reinforcing fibres include glass, aramid, ceramic and various metals e.g.…”

Wear behavior of asbestos-free eco-friendly composites for automobile brake materials

“…Asbestos fiber reinforced polymeric composites are used in brake pads, brake linings and brake couplings; however, asbestos has been found to be hazardous to the environment and to human health [1]. Therefore, in recent years, non-asbestos reinforcements like Kevlar (aramid fiber), glass fiber, graphite, and natural fibers have been used as replacements for asbestos [2].…”

“…Chemically treated flax fibers have been used in eco-friendly brake friction composites to replace aramid pulp in non-asbestos organic friction materials and to replace steel wool in semi-metallic friction composites [1]. Furthermore, basalt fiber is an inorganic fiber with an extremely good modulus, high strength, enhanced strain to failure, high-temperature resistance, excellent stability, good chemical resistance, and good processability [5].…”

Graphene/cardanol modified phenolic resin for the development of carbon fiber paper-based composites

“…With the increase of cardanol content, the number of functional groups involved in the reaction increases, promotes the uniform distribution of pores and facilitates the molding process. [15][16][17] Furthermore, it prevents the particles from agglomerating, effectively relieves the stress, and blocks the crack propagation, thus increasing the tensile strength of the material. However, although cardanol with exible long chains can improve the toughness of the material, too much cardanol content will result in steric hindrance and poor dispersion, which lead to the crack growth and expansion inside composite materials, generating a rapid growth of stress and fracture of bers, resulting in decreased strength.…”