With global annual production of silicone expected to grow to 2.9 million tons by 2025, it is increasingly important to have an environmentally-friendly end-of-life option for silicone products. The current solution for discarding silicone scrap is to either landfill or incinerate it. Both of these are detrimental choices for the environment.
Read MoreSilicones or polysiloxanes belong to a class of elastomers and are often referred to as silicone rubber. The prevailing type of polysiloxanes is polydimethylsiloxane (PDMS). Development began in 1940 when Eugene G. Rochow and Richard Müller independently developed the synthesis of methylchlorosilanes directly from elemental silicon. This discovery marked the beginning of a series of important findings on a new class of materials, namely silicone elastomers. The first silicone based product was a coating for the airplane industry, presented in 1942 by Dow. Presently, silicones are used in thousands of applications. Worldwide, the market for silicone consumption shows steady growth year after year
Read MoreRecent developments in stimuli-responsive or “smart” materials offer the opportunity for major advances in material design that could impact markets for latexes. One of the lesser known, but simpler technologies includes polymers and latexes whose properties can be dramatically, and reversibly, switched simply by adding or removing CO2. The processes used offer advantages in sustainability without requiring expensive materials or catalysts, and are based on currently used materials and production methods. This article will give a general overview of three examples relevant to latexes and coatings
Read MoreDow announced the general availability of its first low density LSR for injection molding as part of its Silastic line, and the LSR is initially available to brand owners and formulators in Europe and North America. The material’s properties make it a favorable option, particularly for food dosing valves, closures, dispensers, seals, gaskets and other food contact applications
Read MoreAn extrusion die is a purpose built tool designed by cutting shapes in plates to reflect an intended extruded rubber product. In advance of an extrusion project, a process engineer designs the die according to specifications of the project and those of the customer, and installs it on an extruder. Often, an extrusion die is made from hard metal, like steel, polished and with sharp edges. Once all plates of the mold or die are created, rubber is forced through them under high pressure in a high temperature zone
Read MoreIt has long been established that unvulcanized solid elastomer compounds can be expanded to sponge forms by the incorporation into the formulation of thermally activated gas releasing chemicals known as blowing agents. During controlled heating of the compound, there is molecular dissociation of these blowing agents, and this is often designed to occur in conjunction with the onset of vulcanization of the compound, enabling the production of a range of sponge structures.
Read MoreRoyalene EPDM, a terpolymer of ethylene, propylene and a
non-conjugated diene, is one of the most versatile specialty
elastomers in commercial use today. The main attributes of
EPDM are its outstanding resistance to oxidation, ozone and
the effects of weathering. It is also highly extendable, allowing
high levels of fillers and plasticizers to be added, while still
maintaining good physical properties
many EPDM grades are still produced using conventional Ziegler-Natta catalysts, molecular catalysts for EPDM production have been adopted readily and have grown rapidly. Dow has introduced its Advanced Molecular Catalyst (AMC) technology as a new benchmark in the EPDM industry by enabling even higher process sustainability and catalyst efficiency
Read MoreHNBR is rated for continuous use at temperatures from125°C to 150°C, depending on several compounding factors, with the choice of cure system being one of the most critical. While a sulfur cure can provide flex fatigue and high tensile properties, it does not have high temperature stability. Peroxide cured HNBR is the only suitable cure system for long term, 150°C temperature resistance. Peroxide cured HNBR also provides high modulus and low compression set, making it an ideal material for sealing applications. HNBR is the sealing material of choice in many automotive and oil well applications where high mechanical strength is needed, in addition to high temperature and chemical resistance
Read MoreLiquid poly(butadiene) resins can be defined as oligomers with a degree of polymerization (Dp) of 100 and molecular weights below the critical molecular weight. These materials have rheology defined as viscous flow at temperatures of less than 60°C. In this regime, properties such as glass transition temperature and viscosity are determined by both microstructure and macrostructure. In applications such as adhesives, thermoplastic modification or tire compounding, liquid poly(butadienes) are often used as high value additives, imparting specific performance enhancement
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