Waxes in rubber
Dr. Holger Bartels; Avokal
Rubber is a material with so much dissimilar and often incompatible components like raw rubbers, fillers,
plasticizers, antioxidants, metal oxides, processing aids, curing agents and curing accelerators – and a number
of different waxes.
Waxes can be biogenic, from fossil sources or synthetic. Waxes of different sources have got different chemical
structures and different technical utilization. Biogenic waxes typically consist of esters of fatty and waxy acids
and alcohols. Waxes that are contained in crude oil are generally hydrocarbons. Synthetic waxes based on
biological material often still have got carboxylic groups. Synthetic waxes from ethylene and similar are
hydrocarbons differing in structure from those from crude oil. Waxes are used for a wide range of purposes, that
rubber technology is only one of.
To handle the broad variety of materials and compose the best products for each purpose – this is the profession
of wax compounders like company Tromm at Cologne, that is represented by company Heinrich Heller. Their
trade names Carnicotect, Polarwachs, Polarit and others are well known in rubber industry.
Waxes fulfil different tasks in a rubber compound. The best known is that of an antioxidant and anti-ozonant.
But there are others, too.
The different chemical structures are shown and the different usages explained.