Propylene motor polymer

The polymerization process is exothermic. The average heat of reaction when motor polymer is made from propylene is 670 B.t.u./lb. In contrast, the average heat of reaction of butylenes to motor polymer is only 400 B.t.u./lb. It is easier, therefore, to control the temperature of a butylene polymerization unit than to control propylene polymerization. 

Propylene-Butylene Motor Polymer This product is the most predominant of those made by polymerization of the olefins from cracked gases. It is a clean-burning fuel having a... 

Some propylene polymerization units are operating for production of motor polymer only. This now is becoming uncommon because many refiners have changed their operations to make tetramer, and others fractionate some tetramer, trimer, or dimer out of the polymer leaving very little, if any, motor gasoline. 

Propellants cast into rockets are commonly case-bonded to the motors to achieve maximum volumetric loading density. The interior of the motor is thoroughly cleaned, coated using an insulating material, and then lined with a composition to which the propellant binder adheres under the environmental stresses of the system. The insulation material is generally a mbber-type composition, filled with siUca, titanium dioxide, or potassium titanate. SiUca-filled nitrate mbber and vulcanizable ethylene—propylene mbber have been used. The liner generally consists of the same base polymer as is used in the propellant. It is usually appHed in a thin layer, and may be partially or fully cured before the propellant is poured into the rocket. 

Propjiene [115-07-17, CH2CH=CH2, is perhaps the oldest petrochemical feedstock and is one of the principal light olefins (1) (see Feedstocks). It is used widely as an alkylation (qv) or polymer—ga soline feedstock for octane improvement (see Gasoline and other motor fuels). In addition, large quantities of propylene are used ia plastics as polypropylene, and ia chemicals, eg, acrylonitrile (qv), propylene oxide (qv), 2-propanol, and cumene (qv) (see Olefin POLYMERS,polypropylene Propyl ALCOHOLS). Propylene is produced primarily as a by-product of petroleum (qv) refining and of ethylene (qv) production by steam pyrolysis. 

Most of the propylene polymerized by this process is used in motor gasoline ("Polymer Gasoline"). However, an appreciable portion of the C7, C, and C,2 olefins find use as feedstocks for production of Oxo alcohols. 

FIGURE 7.9 Polymer composition along a single pol5mier chain for the ethylene-propylene copol5mier employed in most motor oils as the viscosity modifier. 

Steam cracking of various petroleum fractions is gaining widespread use for the production of olefins. These olefins are produced essentially for use as feed stock for numerous petrochemical processes, but the by-product butylenes and propylenes are sometimes used as feed stock for aviation and motor alkylation units. Ethylene is the most important of the olefins produced from this type of cracking, and propylene is second in importance. These two olefins are normally charged to either alkylation or polymerization units for the production of petrochemicals or petrochemical intermediates. Polyethylene and propylene dimers, trimers, tetramers, and penta-mers are some of the more important polymers produced, while ethybenzene, dodecylbenzene, cumene, diisopropylbenzene, and alkylated... 

Another interesting development in the field of crystalline polymer blends was initiated by the Toyota Motor Corporation, which recently introduced a super-olefin polymer. This material was designed on a lamellar level (on a nanometer scale), and it has been speculated that this material is a blend of low-molecular-weight poly (propylene)(PP) with a new olefinic copolymer. This material, which has excellent hardness and toughness, as well as good flow properties, was designed to replace the expensive reaction injection molding (RIM) polyurethane [3]. 

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