Specialty chemicals group LANXESS AG has developed a performance at comparable with natural rubber EPDM –Keltan 9565Q, and natural rubber than aging. Keltan 9565Q ultra-high molecular weight such that it has a similar natural rubber and high strength and elasticity. Moreover, as a saturated polymer, this new product retains the EPDM heat resistance, weather resistance and ozone resistance. Accordingly, Keltan 9565Q better than natural rubber in heat aging, particularly in high-dynamic applications.Furthermore, compared with natural rubber, Keltan 9565Q lower processing costs.
“Mechanical engineering and automotive industry customers demand more able to withstand high operating temperatures long rubber products,” Lanxess Performance Elastomers Business Unit synthetic rubber expert John Beelen explains. “Natural rubber With its high flexibility and tear resistance has been applied in the industrial field, but natural rubber is difficult to meet the increasing temperature requirements.”
Natural rubber has reached the limits of its performance
Despite the poor heat aging properties of natural rubber, but the rubber components subject to high stress (such as shock absorbing member), the natural rubber so far is still considered almost indispensable material. The reason for this dilemma is that the typical molecular structure of this historic material. Natural rubber is a highly ordered long chain molecular structure guarantees its excellent flexibility, but the unsaturated bonds of the polymer main chain to make it easier in case of ozone, oxygen decomposition, or a case of free radicals, ultraviolet light and heat gradually occurrence of secondary crosslinking reaction. This can lead to cracks in the vulcanized natural rubber is subjected to high temperatures and the mid-term brittle. The use of additives to slow the natural process is not a long-term solution.
Excellent test results
LANXESS chemists have developed Keltan 9565Q in a different, more sustainable way to meet the challenge: by improving the synthesis process, to further improve the molecular weight EPDM rubber products, natural rubber and then to achieve the same close dynamic performance – even after heat aging remains the same. “We can use a wide range of tests to prove it,” Beelen said. Lanxess in a lecture this year’s Nuremberg International Rubber Conference (IRC) in the audience during the show featured results. For its tandelta value – a measure of the dynamic performance of the sample reached –Keltan 9565Q and natural rubber similar to a low level. Aging at 100 ℃ and 120 ℃ 168 hours, Keltan 9565Q in tear resistance and elongation rate is achieved better results than natural rubber, which is due to the EPDM having a fully saturated molecular chains . Keltan 9565Q compressive deformation than the traditional natural rubber vulcanization system, and thermal stability at least natural rubber (effective curing system) par. In addition to strength, elasticity and resistance to aging, fatigue life is also very important. In a live demonstration of IRC research report, Keltan 9565Q pre-aged samples with natural rubber samples have considerable life. However, after a little recipe for Keltan 9565Q optimization, fatigue life will be greatly improved, reaching the thermal stability of natural rubber compound of the same level.
New areas of EPDM
“Until today, the high dynamic stress field are still using natural rubber this anti-aging properties of the rubber material is poor, Keltan9565Q EPDM opened up new applications in this field.” Beelen said.”Keltan9565Q can also help extend the maintenance cycle, the engine and components to run faster, more powerful: they can operate at higher temperatures, shock absorbing member will not be exposed to high temperatures and rapid aging.”
Benefits Processing
LANXESS new material and even the process has brought benefits. Compared with natural rubber, EPDM rubber due to molecular chain backbone does not contain a double bond and less prone to reversion. As explained above Beelen, “targets narrow the scope of this polymer, ease of processing, the process more repeatable and consistent.” Meanwhile, the synthetic rubber can be processed at higher temperatures – which can greatly improved productivity.
Translated by Google Translator from http://news.cria.org.cn/6/27837.html
