Automobiles materials

Odor compounds may also be released from the plastic materials used in cars. The variety of plastics and possible chemical compounds is broad, which makes the identification of odor causing compounds an extremely comphcated task. An effective and rapid screening of VOCs and semi-VOCs from materials used in automobiles was developed by utihzing the SPME technique [28]. The low molecular weight compoimds extracted from five different automobile materials included different benzene derivatives, aldehydes, esters, biphenyls, phthalates, butylated hydroxytoluene, phenols, alcohols, styrene, triethylene-diamine, carboxylic acids and ketones. A considerable munber of VOCs and semi-VOCs were detected, indicating that more attention should be paid to the selection of materials and additives for automotive parts. 

Automobiles—Materials. 2. Chemistry, Technical. 3. Automobiles—Design and construction. I. Title. 

Key Laboratory of Automobile Materials (Jilin University), Ministry of Edueation, and School of Materials Science and Engineering, Jilin University, Changehun 130025, China. 

Catalytic converters for automobiles (Materials of Importance box. Chapter 4)... 

ETHYLENE We discussed ethylene production in an earlier boxed essay (Section 5 1) where it was pointed out that the output of the U S petrochemi cal industry exceeds 5 x 10 ° Ib/year Approximately 90% of this material is used for the preparation of four compounds (polyethylene ethylene oxide vinyl chloride and styrene) with polymerization to poly ethylene accounting for half the total Both vinyl chloride and styrene are polymerized to give poly(vinyl chloride) and polystyrene respectively (see Table 6 5) Ethylene oxide is a starting material for the preparation of ethylene glycol for use as an an tifreeze in automobile radiators and in the produc tion of polyester fibers (see the boxed essay Condensation Polymers Polyamides and Polyesters in Chapter 20)... 

Polypropylene fibers for use in car pets and automobile tires consum er Items (luggage appliances etc) packaging material... 

Some commercially important cross-linked polymers go virtually without names. These are heavily and randomly cross-linked polymers which are insoluble and infusible and therefore widely used in the manufacture of such molded items as automobile and household appliance parts. These materials are called resins and, at best, are named by specifying the monomers which go into their production. Often even this information is sketchy. Examples of this situation are provided by phenol-formaldehyde and urea-formaldehyde resins, for which typical structures are given by structures [IV] and [V], respectively ... 

Long-chain esters of pentaerythritol have been used as pour-point depressants for lubricant products, ranging from fuel oils or diesel fuels to the high performance lubricating oils requited for demanding outiets such as aviation, power turbines, and automobiles. These materials requite superior temperature, viscosity, and aging resistance, and must be compatible with the wide variety of metallic surfaces commonly used in the outiets (79—81). 

Specific Tests. Federal (United States) Motor Vehicle Safety Standard (MVSS) 302 is used to measure the burning behavior of materials used in automobile interiors. A specimen is mounted horizontally and ignited for 15 seconds. The burning rate should be below 10 cm /min. The test specimen is 35.5 X 10.1 cm by the actual thickness (up to 1.3 cm). Automakers typically impose more severe criteria than the 10 cm /min in the standard. 

The constmction of vinyl-coated fabrics varies according to its appHcation. A vinyl-coated fabric used for automobile seat covers is shown in Figure 3 a woven fabric is the substrate. The material is durable but stiff and heavy. Incorporating an expanded foam stmcture into the coating layer reduces the weight (Fig. 4), and replacing the woven substrate fabric with a soft knit fabric improves fiexibihty. 

The market for lighter weight P/M materials such as aluminum and titanium aluminides is expected to grow, especially for uses in automobiles. 

Flexible foams are resiUent open-ceU stmctures with densities varying from 25—650 kg/m, depending on the choice of the raw materials. Most flexible foams are produced in the form of a slab or bun in a contiauous process in widths up to 2.4 m and thicknesses up to 1.2 m. A Hquid foamable mixture is pumped onto a conveyor, which moves through a tunnel where reaction and foaming occur (101). Similar mixtures can be placed in a mold and allowed to foam. This process is used in the manufacture of automobile seats (see Foamed plastics). 

These new synthetic mbbers were accessible from potentially low cost raw materials and generated considerable woddwide interest. For a time, it was hoped that the polysulftde mbbers could substitute for natural mbber in automobile tires. Unfortunately, these original polymers were difficult to process, evolved irritating fumes during compounding, and properties such as compression set, extension, and abrasion characteristics were not suitable for this apphcation. 

Alkylated phenol derivatives are used as raw materials for the production of resins, novolaks (alcohol-soluble resins of the phenol—formaldehyde type), herbicides, insecticides, antioxidants, and other chemicals. The synthesis of 2,6-xylenol [576-26-1] h.a.s become commercially important since PPO resin, poly(2,6-dimethyl phenylene oxide), an engineering thermoplastic, was developed (114,115). The demand for (9-cresol and 2,6-xylenol (2,6-dimethylphenol) increased further in the 1980s along with the growing use of epoxy cresol novolak (ECN) in the electronics industries and poly(phenylene ether) resin in the automobile industries. The ECN is derived from o-cresol, and poly(phenylene ether) resin is derived from 2,6-xylenol. 

Some amino resins are used as additives to modify the properties of other materials. For example, a small amount of amino resin added to textile fabric imparts the familiar wash-and-wear quaUties to shirts and dresses. Automobile tires are strengthened by amino resins which improve the adhesion of mbber to tire cord (qv). A racing sailboat may have a better chance to win because the sails of Dacron polyester have been treated with an amino resin (1). Amino resins can improve the strength of paper even when it is wet. Molding compounds based on amino resins are used for parts of electrical devices, botde and jar caps, molded plastic dinnerware, and buttons. 

Polypropylene is used in battery cases and in the replacement of metal parts in automobiles. It is also widely used in consumer products, eg, kitchen wares, trays, toys, and packaging materials. Its future appHcations are expected to include an increased portion of the fibers and filaments markets, especially for continued growth in carpet backing and carpet face yams. Film, both oriented and unoriented, is also expected to be a significant growth market for polypropylene. 

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