131-20-4

Usage

Physical state

Clear, colorless, and odorless liquid

Solubility

Insoluble in water, soluble in most organic solvents

Molecular structure

Ester derived from 1,2-benzenedicarboxylic acid and 6-methylheptyl alcohol

Primary use

Plasticizer for polyvinyl chloride (PVC) products

Applications

Toys, food packaging, wire and cable insulation, flooring, and automotive parts

Properties

Low volatility, excellent resistance to oil and grease, improves flexibility and durability of PVC products

Regulatory status

Subject to scrutiny due to potential health risks, restricted in some countries for certain products, particularly those intended for children.

Upstream product

• 85-44-9 phthalic anhydride 
• 1653-40-3 6-methylheptanol 
• 95-47-6 o-xylene 

Relevant academic research and scientific papers

Dynamics of complex phthalate liquids. 2. Structural effects of side chains

In this paper, the second of a series of two presenting the structural effects on the dynamic properties of complex liquids, we discuss the effect of structural changes in the alkyl side chain on the macroscopic viscosity and microscopic motional behavior of phthalates. 13C NMR spin-lattice relaxation times and nuclear Overhauser enhancements of individual carbon nuclei of di-n-octyl phthalate (DNOP), di-n-hexyl phthalate (DHP), and bis(6-methylheptyl) phthalate (DIOP) have been measured as a function of temperature from -40 to 70 °C. Individual 13C peaks were unambiguously assigned by using 2D 1H-13C chemical shift correlation and specific relaxation of individual carbons in the alkyl chain of the molecule. In addition, the density and viscosity of these compounds as a function of temperature have been measured. The results were also compared with earlier experiments performed on bis(2-ethylhexyl) phthalate (DEHP). The optimized parameters of the Cole-Davidson distribution model obtained from the analysis of the 13C relaxation data provided the detailed information on the internal motions of the alkyl side chains. The NMR relaxation data and shear viscosity of the phthalate liquids were interpreted phenomenologically in terms of the alkyl side chain flexibility. The branching in the alkyl chain restricted the motional degree of freedom of the side chain, which made the molecule less flexible as a whole. The branching near the rigid part of the molecule was found to be more effective in restricting the internal motion of the alkyl chain.

A liquid phase oxidation of O-xylene with esterification coupling preparation of phthalic acid diester method

The invention relates to a method for preparation of diester phthalate by o-xylene liquid-phase oxidation and esterification coupling. In the presence of a catalyst, air or oxygen is used as an oxygen source for preparation of the diester phthalate by o-xylene liquid-phase oxidation and esterification coupling. The method has the advantages of mild reaction conditions, safe operation, low raw material and energy consumption, high conversion rate and high selectivity and the like.

Process for producing carboxylic acid esters and catalysts therefor

A process for producing carboxylic acid esters by the following steps: a) preparation of a reaction mixture containing an alcohol and a carboxylic acid and/or a carboxylic anhydride and/or a carboxylic acid ester and or a partially esterified carboxylic acid, b) heating of this mixture to the suitable reaction temperature in the presence of a solid polysiloxane insoluble in the reaction medium and having sulphonic acid groups with intensive thorough mixing accompanied by continuous separation of the reaction water which forms, wherein the polysiloxane used as the catalyst in modified by treatment with a soluble aluminum, titanium or zirconium compound, and the spherical particles thereof have a diameter of 0.01 to 3 mm, a specific surface of 0.1 to 1200 m2 /g, a specific pore volume of 0.01 to 6.0 ml/g and a bulk density of 50 to 1000 g/l.