In July 2023 we focused on sulphur silanes. This month our focus will be on vinyl silanes. We did cover the introductory part in that article. However, at the risk of being repetitious, but for a stand-alone reader, we will repeat it here…
Silanes have been known for about 50 years. They were originally used in an industrial scale for adhesives and coatings. In the 70s silanes found their way into the rubber industry as coupling agents for while filler.
There seems to be no end in sight, at least in the immediate future for an end of the Russia-Ukraine conflict. Reports on the conflict that once dominated headlines, now finds a small mention on page six or seven of newspaper.
Last month we brought to you Why one should use Dispergum Zinc soaps as a processing aid. As a follow on to that this month we address the all-important question: How do you know your processing aid is working. What follows are various testing methods, for both NBR and CR, for the processes used for conversion to finished rubber products.
In this two-part article, we bring to you why one should use processing aids like Dispergum zinc soaps for NBR and CR and in the next month, the all-important question: How do you know your processing aid is working – this alongside tests to show the efficacy of these processing aids.
The permissible standard for Calcium Oxide is 5 milligrams of CaO per cubic meter of air averaged over an eight-hour work shift. Some countries have recommended 2 milligrams per cubic meter. CaO has been linked to many health hazards like irritation of the eyes, nose, throat and skin. Severe burns may result from contact with this chemical. It may also cause bronchitis and pneumonia. Long term exposure is said to cause skin ulceration and perforation of the nasal septum.
Ethylene-α-olefin elastomers, particularly ethylene-propylene-diene (EPDM) rubbers, are excellent all-purpose rubbers. Environmental factors such as oxygen, heat UV and ozone tend to degrade the rubbers. These factors cause free radicals to form which attach to the polymer chain and make the rubber harder.
Curing in EPDM (Ethylene propylene diene) rubbers is much slower compared to curing in conventional diene rubbers. Therefore, it usually requires a high concentration of highly active curing accelerators. This, though, has its own issues as there is a limit to using high amounts of accelerators, as their activity tends to level off with increased concentration and BLOOMING problems start.
Static electricity has its uses, no doubt. Think laser printers, photocopiers and flash bulbs for photography. Why do we call this static electricity? Static electricity is a kind of electric charge that stays in one place, as in it is really is static. On the other hand, current electricity or electric current), is electricity that moves from one place to another along a definite path called a circuit.
Insoluble sulphur is an important rubber additive. The reason the focus in on the use of INSOLUBLE sulphur is because common soluble sulphur tends to bloom i.e., deposition of sulphur inside or at the surface of the rubber. Insoluble sulphur improves product quality, wearability and resistance to both fatigue and ageing.
