Study on the improvement of self-adhesion of brominated butyl rubber

Abstract

In the field of hydraulic construction, expansion joints are often provided to deal with the thermal expansion and cold contraction of concrete. The water-stop material in the joint not only needs to have good air tightness and adhesion but also needs to have high plasticity. The arrangement of methyl groups in the side groups of the molecular chain of butyl rubber is very close, limiting the movement of macromolecules and chain segments, so it has a very low air permeability and excellent airtightness and is often used as a water-stop material. However, butyl rubber itself has poor self-adhesion and mutual adhesion and needs to be reinforced with the help of adhesion promoters. Although the viscosity of brominated butyl rubber has been improved, its properties still cannot meet the requirements of use. Therefore, brominated butyl rubber with better viscosity was used as the substrate, reinforcing materials, tackifiers and plasticizers were preferably selected, and tackifiers were used as the variable evaluation indexes to study the properties of different kinds of tackifiers and brominated butyl rubber blended with different dosages, and to explore the possibility of its self-vulcanization. The result showed that when the rosin system was selected, carbon black was 50 phr, naphthenic oil was 50 phr, and the rosin portion was 70 phr, the peel strength was up to 41.77 N/25 mm, which means that the tackifying effect was better.

Keywords

brominated butyl rubber / tackifying resin / peel strength / tackifying effect