On this day in science – the rubber fire hose was patented

In 1821, a fire hose of cotton web lined with rubber was patented by James Boyd of Boston, Mass. He invented it to replace riveted leather hose. Leather hose had many drawbacks, including drying out, cracking and bursting from excessive pressure. The introduction of rivets (1807), to replace stitching, had allowed higher pressures and greater delivery of water on the fireground. The improved hose now was 40 to 50 feet in length and weighed more than 85 pounds with the couplings. Hose oilers were developed to keep the leather supple and pliable. Various types of oils and other substances were used to keep the hose in shape. By 1871, the Cincinnati Fire Department was using the B.F. Goodrich Company's new rubber hose reinforced with cotton ply.

Indoor fire hose with a fire extinguisher, by Raysonho @ Open Grid Scheduler / Grid Engine (Own work) [CC0], via Wikimedia Commons

Modern fire hoses use a variety of natural and synthetic fabrics and elastomers in their construction. These materials allow the hoses to be stored wet without rotting and to resist the damaging effects of exposure to sunlight and chemicals. Modern hoses are also lighter weight than older designs, and this has helped reduce the physical strain on firefighters. Various devices are becoming more prevalent that remove the air from the interior of fire hose, commonly referred to as fire hose vacuums. This process makes hoses smaller and somewhat rigid, thus allowing more fire hose to be packed or loaded into the same compartment on a fire fighting apparatus.

There are several types of hose designed specifically for the fire service. Those designed to operate under positive pressure are called discharge hoses. They include attack hose, supply hose, relay hose, forestry hose, and booster hose. Those designed to operate under negative pressure are called suction hoses.

For more information visit:-

https://todayinsci.com/5/5_30.htm

https://en.wikipedia.org/wiki/Fire_hose

http://www.prlabs.co.uk/lab-supplies.php?N=balls-rubber-20mm-&Id=46943

On this day in science history: the first rubberised asphalt road surface was applied

In 1948, the first rubberised asphalt road surface in the U.S. was applied to 6,217-ft of Exchange Street in Akron, Ohio, a city that was home to a large rubber industry. The paving mixture contained 7 to 11 pounds of crumbled synthetic rubber per ton of asphalt. This full-scale use followed a test made on a small section resurfaced in 1947. Goodyear President Paul W. Litchfield proposed the paving material - and donated the rubber - to the city after he had seen its use in Holland, where it had been used since the 1930s and was claimed to be more durable, waterproof and safer in extremes of weather. However, by 1959, wear was judged to be no better than less expensive asphalt alone, and rubber additive is no longer used.

A synthetic rubber is any artificial elastomer. These are mainly polymers synthesised from petroleum by products. About 15 billion kilograms (5.3×1011 oz) of rubbers are produced annually, and of that amount two thirds are synthetic. Global revenues generated with synthetic rubbers are likely to rise to approximately US$56 billion in 2020. Synthetic rubber, like natural rubber, has uses in the automotive industry for tires, door and window profiles, hoses, belts, matting, and flooring.

Chemical structure of cis-polyisoprene, the main constituent of natural rubber.By Smokefoot (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Natural rubber, coming from latex of Hevea brasiliensis, is mainly poly-cis-isoprene containing traces of impurities like protein, dirt etc. Although it exhibits many excellent properties in terms of mechanical performance, natural rubber is often inferior to certain synthetic rubbers, especially with respect to its thermal stability and its compatibility with petroleum products.

Synthetic rubber is made by the polymerization of a variety of petroleum-based precursors called monomers. The most prevalent synthetic rubbers are styrene-butadiene rubbers (SBR) derived from the copolymerization of styrene and 1,3-butadiene. Other synthetic rubbers are prepared from isoprene (2-methyl-1,3-butadiene), chloroprene (2-chloro-1,3-butadiene), and isobutylene (methylpropene) with a small percentage of isoprene for cross-linking. These and other monomers can be mixed in various proportions to be copolymerized to produce products with a range of physical, mechanical, and chemical properties. The monomers can be produced pure and the addition of impurities or additives can be controlled by design to give optimal properties. Polymerization of pure monomers can be better controlled to give a desired proportion of cis and trans double bonds.

For more information visit: 

http://www.todayinsci.com/9/9_07.htm

https://en.wikipedia.org/wiki/Synthetic_rubber

http://www.prlabs.co.uk/lab-supplies.php?N=mat-rubber-61x91cm&Id=66895