Protection against rubber aging

Rubber is everywhere. This sealing, damping, cushioning and insulating material is highly versatile but requires protection against aging that is tailored to the specific stresses encountered. With this in mind, the Advanced Industrial Intermediates (AII) business unit of specialty chemicals company LANXESS launched a raft of staining and non-staining antioxidants and antiozonants for the rubber industry. Depending on their chemical structure, antioxidants and antiozonants counteract one or more aging processes. 

 

Each antioxidant/antiozonant has a typical efficacy spectrum with regard to the various types of aging. As Dr. Jens-Hendrik Fischer, head of AII’s Antioxidants and Accelerators (AXX) unit, puts it: “We provide global support for the rubber processing industry with a wide-ranging selection of products and proven technical expertise. With decades of experience, we have the necessary know-how to recommend appropriate rubber chemicals for our customers’ processing operations.”

 

With its Vulkanox, Vulkacit, Vulkazon and Renacit brands, LANXESS is one of the few manufacturers to offer additive for every step in the rubber manufacturing process from a single source.

 

Vital to humans – harmful to rubber

Aging processes, which are primarily triggered by the effects of oxygen, ozone and heat, change the properties of vulcanizates and can lead to their partial or total destruction over time. The resistance of rubber items to oxygen, ozone and other reactive substances mainly depends on the elastomer on which the compound is based and on the chemicals added to retard the destructive process. 

 

NR (natural rubber), which is used to make items such as truck tires, absorbs far more oxygen than SBR (styrene-butadiene rubber), NBR (nitrile-butadiene rubber) or IIR (butyl rubber) over the same period. Unsaturated groups (such as carbon-carbon double bond content) in the rubber molecule react with oxygen and ozone. This can result in hardening, embrittlement, crazing effects and fatigue. The rubber article is ultimately destroyed.

 

As Melanie Wiedemeier-Jarad, Technical Service Manager in the AXX unit, explained that the company exhibited 14 high-performance rubber chemicals for the rubber processing industry at K 2016. For the most part, LANXESS offers these products in the form of granules for easy, safe and low-dust metering and incorporation. The most important thing, though, is that they can be combined to further enhance a particular additive’s specific efficacy spectrum. 

 

LANXESS’s Vulkanox antioxidants and Vulkazon antiozonants significantly extend the lifespan of elastomers. As a result, items such as truck tires, technical rubber goods and fire hoses can remain in use and retain the required properties for longer. 

 

 

AII has developed a highly effective peptizing agent in the form of wax granules called Renacit 11/WG that makes natural rubber easier to process by breaking down the molecular chains.

 

In addition to antidegradants, the Advanced Industrial Intermediates business unit also demonstrated its Vulkacit vulcanization accelerators, which help to optimally regulate the manufacture of rubber products. By interfering in the reaction between sulfur and the elastomer molecules that forms the basis of vulcanization, Vulkacit has a positive influence both on the speed of the crosslinking reaction and on the properties of the vulcanized products, which then combine outstanding tensile strength, elasticity, elongation at break and hardness with a longer service life.

 

The AII business unit is one of the world’s leading manufacturers of high-quality industrial chemicals for producing agrochemicals, polymers and surface coatings. Further important applications include cosmetics, flavorings, fragrances, fuel additives, lubricants and construction chemicals.