Reduce tire weight

Research with tires continues to be active with the end goals of reducing tire weight and increasing tire lifetime. For example, truck tires are now capable of running 750,000 miles with the carcass married to four tire threads. The truck tire liners weigh about 9 lb. 

The tires account for two-thirds by mass of the elastomer used in an automobile [1]. However, the usage of lightweight steel cord and technical improvements in elastomeric materials have reduced their weight by -20% and this in turn has led to an overall reduction in vehicle weight, concomitant fuel savings, and better road holding property. 

A product of this type will have over 50% of its weight derived from maleic anliydride. This veiy high content of reactive double bonds will lead to a very brittle solid when it is cross-linked witli styrene. Witliout furtlier modification, this solid material will have veiy high tensile moduli, probably over 600 kpsi, but a very low tensile elongation, way below 1 %. Such a brittle material obviously has only very limited applications. Thus, for most general-puipose applications, it is necessary to incoiporate some chemically inert components to soften tire polymer backbone. This will reduce tire cross-linking density and improve the physical properties of tire cured solid. 

Now dynamically vulcanized rubber-plastic blends are poised to enter the realm of automobile tires. A TPV comprising a PA thermoplastic phase with isobutylene-co-p-methylstyrene (BIMSM) rubber can be used as an innerliner, outperforming either historical butyl rubber or the more classical halobutyl and its blend with natural rubber. These and future developments are targeting down-gauging of the barrier film thickness to simultaneously reduce both tire weight and reduced air permeation. A five-to-tenfold reduction in the latter is claimed to be feasible along with improved tire performance (Tsou 2007). 

Figure C2.1.5. Reduced osmotic pressure FT / (RTc as a function of the weight concentration c of polystyrene (M = 130 000 g mor ) in cyclohexane at different temperatures. At 7"= 35 °C and ambient pressure, tire solution is at tire 0 conditions. (Figure from 1741, reprinted by pennission of EDP Sciences.)...

This dissipative force is proportional to the relative velocity of the two beads and acts so as tc reduce their relative momentum, v is tire difference between the two velocities (Vy = v, — v ) and vP rjj) is a weight function that depends upon the distemce and disappears for interbead distances greater than unity (i.e. r ). 

This gain has not come entirely at the expense of fuel economy, however. Over that same twenty-year span, the fuel economy of the average new U.S. car increased by 80 percent. These advances are attributable to lower vehicle weight, improved tires, reduced aerodynamic drag, improved transrnissious, and gains in engine efficiency. 

Advances in materials science have been a leading factor contributing to improvements in vehicle fuel economy and performance since the 1973 oil embargo. Better tire materials have reduced rolling resistance, better materials for moving parts have reduced friction, and most importantly lighter body parts have reduced the overall weight of vehicles. 

The low condensation of diacyl chloride and bis-orf/zo-aminophenol gave a polyhydroxy amide that was submitted to a thermal dehydration.185 187 The two functions of an aminophenol could be acylated, and the question of chemose-lective acylation has been discussed.188 The problem is not O-acylation versus N-acylation because the N-acylated product is tire more stable isomer, but the question is how to control N-monoacylation versus diacylation that could reduce the molecular weight. It has been shown that the condensation in the presence of inorganic salt (LiCl) in NMP gives selectively the N-monoacylated... 

Lower-aspect ratio for automobile tires, higher load-carrying capacity, and reduced size for tmck tires would be key sectors for development. Farm and off-road tire will face demand for higher speeds, more ride comfort, and enhanced traction. Development of advanced higher-strength reinforcement will lead to lower weight and reduced thickness for the tire. 

Large frontal areas create air turbulence and drag. Bodies derived from wind tunnel testing can provide a more smooth air flow around the vehicle. Details such as mirrors, rain gutters, trim, wheel wells and covers can also be more appropriate for air flow. Radial tires can reduce fuel consumption as much as 3%. Puncture-proof tires of plastic could save even more and eliminate the cost and weight of a spare tire and wheel. 

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