Development of vibration damping materials based on butyl rubber: A study of the phase equilibrium, rheological, and dynamic properties of compositions

A detailed study of butyl rubber-based vibration damping formulations linking their composition, morphology, phase structure, viscosity, mechanical loss factor, and other characteristics is presented for the first time. High performance of the compositions including aromatic petroleum oil is explained by limited solubility of the plasticizer that leads to the formation of a highly-viscous emulsion (eta(20 degrees C) approximate to 1000 Pa center dot s) consisting of a swollen butyl rubber matrix and dispersed oil droplets in the broad composition range. Chalk is found to be the best inorganic filler as its spherical particles provide strong adhesion to the reinforcing layer of aluminum foil. Aiming to eliminate ecologically unfriendly aromatic compounds, a new low-cost binding agent formulation based on butyl rubber mixed with polyisobutylene and highly refined mineral oil is suggested. Being environmentally safe, it possesses high viscosity of 1000-3000 Pa center dot s, cohesion strength of 3.5-5.0 N/cm, penetration of 4.5-6.0 mm, and mechanical loss factor up to 0.34 at room temperature, which are as good as, or even better than, the properties of currently produced vibration damping materials containing aromatic compounds. New materials can be used in car and aircraft parts for effective vibration isolation.

Automated summary

A detailed study of butyl rubber-based vibration damping formulations reveals high performance achieved through limited solubility of the plasticizer. Chalk is identified as the best inorganic filler for strong adhesion. A new environmentally friendly and cost-effective binding agent formulation is proposed as a replacement for materials containing aromatic compounds, offering comparable or superior properties.