The Uses of Benzenedicarboxylic Acid

Three structural forms of benzenedicarboxylic acid exist. Although they basically consist of the same chemical, the structure of each type causes it react differently. Phthalic acid (1.2-benzenedicarboxylic) comes in the form of colorless crystals that are soluble in alcohol and slightly soluble in water and ether. Isophthalic acid (1.3-benzenedicarboxylic acid) forms white crystals that are slightly soluble in water, alcohol and acetic acid. Terephthalic acid (1.4-benzenedicarboxylic) is a white powder soluble in water, alcohol and ether.

Uses of Phthalic acid (1.2-Benzenedicarboxylic Acid)

• Phthalic acid, used to a much lesser extent than the other benzenedicarboxylic acids, primarily serves as a component in making some resins, dyes and pigments. The acid had previously been added to plastics due to its ability to increase desirable enhancements, such as flexibility, transparency and durability. The use of phthalic acid has faded out due to health risks contributed to the acid as well as its ability to leach into groundwater and topsoil. As of April 2011, the federal government is in the process of banning phthalic acid.

Uses of Isophthalic acid (1.3-Benzenedicarboxylic Acid)

• Isophthalic acid has many uses in the manufacturing of plastics. Often used to produce gel coats and other coatings that benefit from its hardness, corrosion and stain resistance as well as its resistance to heat, this acid plays a role in the manufacturing of polyesters for marine and automotive tanks and corrosion-resistant pipes. It's also an ingredient in coatings for home appliances, automobiles, aluminum siding and metal office furniture. As of April 2011, recent research has tested the use of 1.3-benzenedicarboxylic acid as a potential active ingredient in new antibacterial drugs as well as new drugs to fight leukemia.

Uses of Terephthalic acid (1.4-Benzenedicarboxylic Acid)

• Terephthalic acid (1,4-benzenedicarboxylic acid) is primarily used as a raw material for polyester fibers. The other major use for the terephthalic acid is to produce polyethylene terephthalate (PET) --- the material of most plastic containers used in the food industry, including beverage bottles. Terephthalic acid is also used in the production of dyes, synthetic perfumes, medicines, poultry feed additives and some pesticides. In research laboratories, Terephthalic acid plays a role in the development of metal-organic frameworks --- a mixture of metal ions and organic chemicals to produce porous materials that can contain gases as well as filter gases. It plays a role in the containment of hydrogen and carbon dioxide gases.

Harmful Effects of Benzenedicarboxylic Acid

• Although benzenecarboxylic acid has proven useful, the acid can cause extreme damage to animal and plant life, including humans. Exposure to benzenecarboxylic acid, whether through food, water or vapors given off by products made with it, can cause disruptions in the human endocrine system, which controls the release of hormones in the body. In wildlife, exposure to benzenecarboxylic acid may have caused the feminization of male animals. In people, the major concern holds that exposure may cause both obesity and type II diabetes by disrupting the normal production of hormones. The acid and its compounds have carcinogenic qualities. Benzenedicarboxylic acid has become so prevalent in our lives that nearly every human urine test will detect a small level of the acid.