Plasticizers play an important role in biopolymer production

Plasticizers play an important role in biopolymer production. They improve film handling and flexibility, prevent pores and cracks and allow for easy blending with other raw materials.

There is an increasing interest in natural-based plasticizers that are derived from renewable raw materials. These include epoxidized triglyceride vegetable oils from soybean oil, linseed oil and castor oil, and fatty acid esters.

Phthalic Anhydride

Phthalic anhydride is used in the manufacture of phthalate plasticizers and unsaturated polyester resins. It is also employed in the production of alkyd resins for surface coatings. It is a white to slightly gray, glossy solid with a faintly pronounced odor. It has a melting point of 64°F and a flash point of 305°F. It is produced by the air oxidation of naphthalene or o-xylene and in fluidized bed oxidation processes using petroleum or coal tar naphthalene.

It is soluble in alcohol and some organic solvents. It has moderate toxicity by inhalation and is irritating to the skin. It is stored in safety cylinders and transported by truck or tank car. It can be handled under dry, chemical-resistant gloves but must be kept away from acids, strong oxidizing agents, amines, and bases. It reacts exothermically with water and can be explosive. It reacts with the anhydride form of copper oxide at elevated temperatures to produce mixtures of phthaloyl nitrates and nitrites.

Poly Vinyl Chloride Phthalate

Phthalate plasticizers are used to soften polyvinyl chloride (PVC) so it can be shaped, molded and fabricated into products. These odorless, low-volatile liquids or solids, like the cartilage in your knee, work by inserting themselves between segments of the PVC molecules. This enables it to bend and flex as needed, just as the knee bends and moves.

They are also needed to keep flexible PVC from degrading in harsh weather conditions such as freezing temperatures, so it can be used for things like swimming pool liners and garden hoses. They are also found in footwear and rain gear.

Exposure to phthalates is of concern from both public health and environmental perspectives. The phthalates DEHP, DBP, BBP and DIBP are classified as toxic to reproduction in the European Union (EU) and the use of these phthalates is restricted for children’s toys and childcare articles. The bio-based plasticizers Grindsted SoftnSafe (made by Eastman Chemical) and Hexamoll DINCH (made by BASF) perform better than the petroleum-based phthalates on most health and environmental hazard endpoints but still have a moderate risk of endocrine disruption.

Phthalic Acid

Phthalic acid, also called phthalate, is an aromatic dicarboxylic acid with an ortho disposition. It is a toxic white crystalline compound. It is a key raw material in the manufacture of phthalates and other plasticizers and used in paints, coatings and insecticides. Phthalic anhydride is presently produced by catalytic air oxidation of o-xylene and/or naphthalene.

It reacts readily with alcohols to form the half-esters, or alkyl hydrogen phthalates (XII), which upon further esterification with sulphuric acid give rise to the dialkyl phthalates (XIII). Phthalic anhydride is moderately flammable and is a white solid when dry, but becomes a clear colorless liquid when molten. It has a characteristic pungent, suffocating odor and is moisture sensitive.

TCC’s phthalic anhydride is utilized as a chemical intermediate for the production of phthalate esters, which act as plasticizers, in polyvinyl chloride and other surface coatings. This product has witnessed a slump in demand during the COVID-19 pandemic outbreak due to suspension of building and construction activities, alongwith halt of automotive production.

Octanol

Octanol is a colorless liquid that has been used for many purposes, including as a plasticizer raw material. It is a very versatile substance that can be combined with a variety of other chemicals to produce plasticizers, extractants, and stabilizers as well as being an intermediate for solvents and fragrances.

In addition, octanol can be esterified with phthalic acid to form a number of polyvinyl chloride (PVC) plasticizers, such as the diesters bis (2-ethylhexyl) phthalate (DOP, DEHP) and triester tris (2-ethylhexyl) trimellitate (TOTM). Its low volatility also makes it useful as an ingredient in lubricants.

When octanol is added to water, the compound partitions between the two phases, and the concentration of the analyte can be determined using HPLC, chemiluminescent nitrogen detector or liquid chromatography-mass spectrometry (LC/MS). 1H NMR can also be used to determine this concentration, but has limited sensitivity due to the unsubdued water signal intensity. Therefore, careful manual phase correction of the 1H spectrum is required.