VESTENAMER®
THE WORLD'S MOST VERSATILE RUBBER ADDITIVE
VESTENAMER® has been used as an additive in the rubber industry for years. By virtue of its properties, the versatile polyoctenamer can solve a variety of problems in the compounding and processing of rubber. It can also improve the dynamic properties of the vulcanized material and as well be used to recycle waste rubber.
VESTENAMER® is a semicrystalline polyolefine additive that is also described as a transoctenamer rubber (TOR) since it is based on cyclooctene and shows a high proportion on trans-double bonds. As a polymeric processing aid, it acts as a plasticizer of rubber compounds in the mixing and manufacturing process. Due to the presence of double bonds, VESTENAMER® takes part in the vulcanization process and is incorporated into the rubber matrix. Therefore, one can consider VESTENAMER as a reactive plasticizer.
THE PROPERTIES OF VESTENAMER®:
- low melting point - low viscosity in the melt (Mooney <10)
- high crystallinity, fast recrystallization rate
- high percentage of macrocycles (>30 %)
- a double bond every eighth carbon Atom
- high proportion of trans-configured double bonds
LOW VISCOSITY ABOVE THE MELTING POINT
VESTENAMER® has a high macrocycle content that significantly reduces its molecular weight. Unlike linear macromolecules, macrocycles can crosslink to a completely three-dimensional network, even at low molecular weight. Combined with a broad molecular weight distribution, its low molecular weight is also responsible for its unusually low viscosity at temperatures above the melting range. At 100 °C VESTENAMER® shows a Mooney viscosity ofless than 10 units.
APPLICATIONS
ROAD CONSTRUCTION
VESTENAMER® FOR ROAD CONSTRUCTION - INNOVATION FOR POLYMER-MODIFIED ASPHALT
The quality and durability of roads is an increasingly important issue for policymakers. The public is becoming increasingly aware of the need for high-performance construction materials for roads to prevent ruts and cracks—and, therefore, save on maintenance costs. At the same time, raw material costs for asphalt, especially for asphalt modifiers, increased and stand in stark contrast to the intended objective of cost-effective road construction. Evonik’s patented process for mixing VESTENAMER® polyoctenamer with crumb rubber, or ground tire rubber (GTR), and the addition of this compound to road bitumen or road asphalt can help solve these problems and thereby improve the condition of roads.
VESTENAMER® SOLVES THE PROBLEMS OF MIXING AND APPLYING ROAD PAVEMENT
The use of ground tire rubber (GTR) to enhance the durability and performance of asphalt concrete pavements is well recognized. At the same time, conventional, sticky GTR/asphalt compounds cause problems in processing. A small addition of VESTENAMER® pellets dramatically overcomes these problems, leading to an easier-to-process mix.
- The VESTENAMER®/GTR mix makes roads more resilient to heavy traffic loads.
- The VESTENAMER®/GTR mix is particularly suitable for use with open-pored asphalts (OPA) and stone mastic asphalt(SMA). It can help reduce ice formation, noise level, embrittlement and cracking.
- Thinner coats are often sufficient for preventive maintenance.
- Scrap tires can be used to the advantage of the environment.
RUBBER GOODS
VESTENAMER® FOR MECHANICAL RUBBER GOODS
VESTENAMER® is used as a processing aid for the rubber industry. In the production of masterbatches, to increase the compatibility of rubber blends, and to simplify rubber recycling.
VESTENAMER® FOR PROFILE EXTRUSION
In many areas of profile extrusion, the use of VESTENAMER® as an additive has become state-of-the-art.
PROFILE EXTRUSION
Extruders are already taking advantage of its ability to:
- Increase the stability of the raw Profile
- Improve flowability
- Improve surface smoothness
- Increase dimensional stability
- savings in specific energy consumption,
- low extrudate swell
Use in extremely hard profiles (e.g. profile mounts for angle profiles) is a particularly time-tested application. Here, VESTENAMER® results not only in increased vulcanization strength but significantly improved processability.
THE ADVANTAGES OF VESTENAMER® IN PROFILE EXTRUSION APPLICATIONS
With extremely low screw speeds, length and melt output as well as melt pressure in front of the nozzle is the same, while the extrudate swell and the specific energy consumption for compounds that contain VESTENAMER® are lower. As screw speeds increase, the length and melt output of such compounds increase quite sharply, as is the case with pure EPDM compounds.
Conversely, the melt pressure in front of the nozzle and the specific energy consumption behave just the opposite: the higher the screw speed, the more significant the difference between compounds with and without VESTENAMER®. For the former, the values are consistently lower.
The advantages of VESTENAMER® are particularly clear at higher screw speeds, whereby increased length and melt throughputs in the double-digit percentage range are obtained
- at lower values for specific energy consumption,
- melt pressure, and
- extrudate swell.
VESTENAMER® FOR HOSE EXTRUSION
In many areas of hose extrusion, the use of VESTENAMER® as an additive has become state-of-the-art.
HOSE EXTRUSION
Because compounds that contain VESTENAMER® 8012 have significantly reduced viscosity and improved flowability, the production of hoses such as brake hoses is fully controllable.
Improved flowability at increased temperatures results in improved layer adhesion and increased penetration of the fabric used for reinforcement.
Because of its crystallinity, VESTENAMER® results in a noticeable increase in hardness and green strength of the unvulcanized inner hoses already at ambient temperature—an effect that continues during cooling. In many cases, therefore, the use of an energy-intensive cooling process at sub-zero temperatures to increase hardness and green strength can be significantly reduced or even completely avoided.
Adding small amounts of polyoctenamer improves the homogeneity of rubber compounds—that is, the distribution of fillers and additives. Initially, this causes no appreciable reduction in viscosity but rather a slight increase in some cases. By adding higher amounts, however, the viscosity-lowering effect of VESTENAMER® prevails. The opportunity to reduce the mixing viscosity and therefore increase the flowability of the compound by exchanging some of the basic polymers for TOR plays an important role in making difficult compounds (those with little or no plasticizer content) controllable and improving fabric penetration.
VESTENAMER® FOR CABLE EXTRUSION
In many areas of cable extrusion, the use of VESTENAMER® as an additive has become state-of-the-art.
CABLE EXTRUSION
In cable extrusion, as in hose extrusion, VESTENAMER® reduces mixing energy in the inner mixer during compounding. Because of the lower output temperature of the compound in cable extrusion, mixing steps are reduced.
VESTENAMER® also significantly improves the extrudate surface without impairing the physical and electrical properties of the vulcanizate. The double-bond content of the polyoctenamer may result in a marginal increase in the compression-set values, which can point to a lower polymerization density.
VESTENAMER® is compatible with all rubber types with saturated or unsaturated hydrocarbon chains.