Phthalates, or phthalate esters and phthalic acid. They are mainly used as plasticizers, that are, substances added to plastics to increase flexibility, transparency, durability and longevity. They are primarily used to soften polyvinyl chloride (PVC).

Low molecular weight phthalates from C3-C6 alcohols are gradually replaced by many products related to health problems in the United States, Canada and the European Union. They are replaced by high molecular weight phthalates (those with more carbon than 6 in their backbone, which are more stable and enduring). The industrial market was still dominated by high phthalate plasticizers; However, due to legal provisions and increased environmental awareness and perceptions, manufacturers are increasingly forced to use phthalate-free plasticizers.

Prevalence and human exposure

Because most of the softened plastics contain phthalates, most people are exposed to some phthalates. For example, in the tests carried out by the Turks, metabolites of the human body possessed phthalate esters in their urine samples. It has been shown that rodents exposed to certain phthalates change their high levels of hormonal levels and cause birth defects.

Phthalate Uses

PVC is widely used in the sewer pipe due to its low cost, chemical resistance and ease of bonding. Phthalate softeners are essential for the use of PVC, which is generally very fragile.

Phthalates are used in a wide variety of products, from enteric drug pills and nutritional supplements to viscosity control agents, gelling agents, film-forming agents, stabilizers, dispersants, lubricants, binders, emulsifying agents and suspending agents. Recent applications can be found in adhesives and adhesives, agricultural additives, building materials, personal care products, medical devices, detergents and surfactants, packaging, children's toys, modeling clay, candles, paints, leather belts, shoes and textiles.

Printing inks and coatings, pharmaceuticals, food products and textile products. Phthalates are also frequently used in soft plastic fishing lures, caulk, paint pigments and sex toys called "jelly rubber". Phthalates are used in various household applications such as shower curtains, vinyl floors, adhesives, floor tiles, food containers and packaging materials and cleaning materials. Personal care products containing phthalate include perfume, eye shadow, moisturizer, nail polish, liquid soap and hair spray.

Phthalates are also found in medical applications such as modern electronics and catheters and blood transfusions. The most commonly used phthalates are di (2-ethylhexyl) phthalate (DEHP), diisodecyl phthalate (DIDP) and diisononyl phthalate (DINP). DEHP is the dominant plasticizer used globally in PVC due to its low cost. Benzylbutylphthalate (BBP) is used in the production of foamed PVC, which is often used as a flooring material, although its use in Western countries has declined rapidly. Perfumes and pesticides in solvents used as phthalates with small groups R and R '.

Approximately 8,4 million tons of plasticizers are produced annually in the world, resulting in products produced in Europe at around 1,5 million mt. Approximately% 70 of these sums is phthalate and is recently around 88. The remaining 30 is alternative chemistry. The plasticizers contribute to the 10-60 of the total weight of the plasticized products. More recently in Europe and the US, regulatory developments have led to a change in phthalate consumption, with higher phthalates (DINP and DIDP) changing DEHP to general purpose plasticizers because DIDP and DINP are not classified as hazardous. All of these phthalates are now regulated and limited in many products. Although DEHP has been shown to not pose a risk when assessing practices using risk assessment methods, Category 1B is classified as reprotoxin and is now included in the Annex XIV of the European Union. The REACH legislation and DEHP have been revoked in Europe under REACH and may only be used in certain cases with certain limitations. The European Commission, after receiving the opinion of the European Chemicals Agency (ECHA), the Risk Assessment Committee (RAC) and the Socio-economic Analysis Committee (SEAC), is given by the European Commission on a limited basis.

History of Phthalate

The development of cellulose nitrate plastic in 1846 was produced with the castor oil patent for use as the first plasticizer in 1856. In 1870, camphor was the more preferred plasticizer for cellulose nitrate. Phthalates were first introduced in 1920s and quickly replaced the volatile and odorous camphor. In 1931, the commercial presence of polyvinyl chloride and the development of di (2-ethylhexyl) phthalate led to the plasticizer's explosion of the PVC industry.

Phthalate Properties

Phthalate esters are dialkyl or alkyl aryl esters of phthalic acid (also called 1,2-benzenedicarboxylic acid, which should not be structurally mixed with isomeric terephthalic or isophthalic acids); The term "phthalate" is derived from phthalic acid derived from the word & quot; naphthalene & quot ;. When added to plastics, the phthalates allow long polyvinyl molecules to slide against each other. Phthalates have an open syrup liquid consistency and show low water solubility, high oil solubility and low volatility. Polar carboxyl R and R 'contribute little to the physical properties of phthalates, except when they are too small (eg, ethyl or methyl groups). Phthalates are odorless liquids produced by reacting colorless, phthalic anhydride with a suitable alcohol (usually 6-13 carbon).

The mechanism by which phthalates and related compounds affect plasticization to polar polymer has been a subject of intensive study since 1960s. The mechanism is one of polar interactions between the polar centers of the phthalate molecule (C = O functionality) and the positively charged areas of the vinyl chain, typically located on the carbon atom of the carbon-chlorine bond. For this, the polymer should first be heated in the presence of plasticizer on the Tg polymer and then to a melting state. This allows the formation of a close mixture of the polymer and the plasticizer and the realization of these interactions. When cooled, these interactions remain and the network of PVC chains cannot reform (as in non-plasticized PVC or PVC-U). The alkyl chains of phthalate then separate the PVC chains. They are mixed in the plastic ware as a result of the production process.

Since they are generally not chemically bound to plastics, the phthalates are released from the plastic material by relatively soft means. For example, they can be removed by heating or by extraction with organic solvents.

Alternatives to Phthalate

There are many biological alternatives in the market. The problem is that it is typically expensive and not compatible as the primary plasticizer. However, Dioctyl terephthalate (a terephthalate isomeric with DEHP) and 1,2-Cyclohexane dicarboxylic acid diisononyl ester (a hydrogenated version of DINP) are available in cost-competitive pricing and good plasticization properties.

A vegetable oil-based plasticizer has been developed which uses a single reactor synthesis and is compatible as the primary plasticizer. Dioctyl is a readily available for phthalate. And many other bio-based plasticizers are being developed and expanded as an alternative to phthalates.

Phthalate Table (Used)

Tests and analyzes of phthalate and phthalate esters as well as FTALAT FREE certification (phthalate-free) can be contacted by TÜRCERT.