Tribological Performance and Thermal Stability of Nanorubber-Modified Polybenzoxazine Composites for Non-Asbestos Friction Materials.

Chanchira Jubsilp,Jakkrit Jantaramaha,Sarawut Rimdusit,Phattarin Mora

doi:10.3390/polym13152435

Chanchira Jubsilp, Jakkrit Jantaramaha + Show 2 more

Open Access

https://doi.org/10.3390/polym13152435

Copy DOI

Journal: Polymers	Publication Date: Jul 23, 2021
Citations: 14	License type: CC BY 4.0

Affiliation: Srinakharinwirot University, Chulalongkorn University

Abstract

Asbestos-free friction composite based on ultrafine full-vulcanized acrylonitrile butadiene rubber particles (UFNBRPs)-modified polybenzoxazine was successfully developed. The UFNBRPs-modified polybenzoxazine friction composite was characterized for chemical, tribological, and mechanical properties as well as thermal stability. The UFNBRPs not only act as a filler to reduce noise in the friction composites due to their suitable viscoelastic behaviors but also play a key role in friction modifiers to enhance friction coefficient and wear resistance in the polybenzoxazine composites. The chemical bonding formation between UFNBRPs and polybenzoxazine can significantly improve friction, mechanical, and thermal properties of the friction composite. The outstanding tribological performance of the friction composite under 100–350 °C, i.e., friction coefficients and wear rates in a range of 0.36–0.43 and 0.13 × 10−4–0.29 × 10−4 mm3/Nm, respectively, was achieved. The high flexural strength and modulus of the friction composite, i.e., 61 MPa and 6.4 GPa, respectively, were obtained. The friction composite also showed high thermal stability, such as 410 °C for degradation temperature and 215 °C for glass transition temperature. The results indicated that the obtained UFNBRPs-modified polybenzoxazine friction composite meets the industrial standard of brake linings and pads for automobiles; therefore, the UFNBRPs-modified polybenzoxazine friction composite can effectively be used as a replacement for asbestos-based friction materials.

Highlights

Polymer composite materials composed of different reinforcements and fillers into several engineering polymers to replace metallic and ceramics are currently used in structural applications such as automotive, construction, spacecraft, marine, etc. [1,2,3]
Asbestos as a reinforcement for brake pads has been the most widely used in all kinds of vehicles due to its excellent thermal stability, tribological properties, and low cost
Polymer friction materials currently used as brake pads can contain more than 10 different ingredients, which are often categorized into four classes of ingredients, including binder, i.e., phenolic and epoxy resins (10–30 wt%), reinforcing fibers, i.e., glass fiber, aramid fiber, and metallic fiber (5–40 wt%), friction modifiers, i.e., graphite, alumina powder and metal oxides (5–35 wt%), and fillers, i.e., barium sulfate, calcium carbonate, cashew dust, and rubber dust (40–80 wt%) [3,4]

Summary

Introduction

Polymer composite materials composed of different reinforcements and fillers into several engineering polymers to replace metallic and ceramics are currently used in structural applications such as automotive, construction, spacecraft, marine, etc. Polymer friction materials currently used as brake pads can contain more than 10 different ingredients, which are often categorized into four classes of ingredients, including binder, i.e., phenolic and epoxy resins (10–30 wt%), reinforcing fibers, i.e., glass fiber, aramid fiber, and metallic fiber (5–40 wt%), friction modifiers, i.e., graphite (synthetic and natural graphite), alumina powder and metal oxides (5–35 wt%), and fillers, i.e., barium sulfate, calcium carbonate, cashew dust, and rubber dust (40–80 wt%) [3,4]

Methods

Results

Conclusion