Dr. Trinh Van Dung at Ho Chi Minh City University of Technology has successfully researched and developed brake pads made from cashew nut shell oil, contributing to fuel savings and reducing environmental harm.
According to Vietnamese standards, brake pads have traditionally been produced from phenol-formaldehyde (PF) resin, chrysotile asbestos (comprising 30-70%), and other additives. Brake pads are a crucial component of the braking system in road vehicles but are often prone to damage and require replacement.
While PF resin brake pads meet high mechanical property requirements, they exhibit poor impact resistance, reduced wear, thermal conductivity, water resistance, flexibility, and low-temperature tolerance. Furthermore, in 1986, environmental protection agencies banned the use of chrysotile asbestos in brake pad production due to its harmful effects on health and its classification as a lung cancer agent.
Since December 2004, Dr. Trinh Van Dung from the Research Center for Refining and Petrochemicals at Ho Chi Minh City University of Technology has been pursuing a research project focused on the technology and equipment for producing friction powder from cashew nut shell oil to manufacture brake pads for road vehicles.
Through his research on the components of cashew nut shells, the author discovered that cashew nut shell oil is a mixture of natural alkyl phenols, characterized as viscous, reddish-brown liquid, which is slightly soluble in water but insoluble in alcohol and ether. The main chemical components of cashew nut shell oil include Cardanol, Cardol, 2-Methyl Cardol, and their polymers, giving it properties similar to both phenol and that of a drying oil or mixture.
Building on these findings, Dr. Trinh Van Dung utilized the physicochemical properties of cashew nut shell oil to create a thermosetting resin and friction material for brake pads. Notably, he developed a mixing device with two counter-rotating horizontal screws, suitable for producing friction components. This device performs both mixing and grinding functions, preventing the mixture from clumping together and effectively breaking down the outer layers of solid particles, facilitating a quicker and more thorough reaction.
By April 2006, the author had produced the first sample products, which were presented at the scientific council of the Ho Chi Minh City Department of Science and Technology. Dr. Phan Minh Tan, Deputy Director of the Department, remarked: “This research project focuses on utilizing domestic materials, making it a very appropriate direction in line with current trends.“
