m-Xylene is an aromatic hydrocarbon

Hydrocarbon

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

, based on benzene

Benzene

Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....

 with two methyl substituent

Substituent

In organic chemistry and biochemistry, a substituent is an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon...

s.

It is an isomer of o-xylene

O-Xylene

o-Xylene is an aromatic hydrocarbon, based on benzene with two methyl substituents bonded to adjacent carbon atoms in the aromatic ring .It is a constitutional isomer of m-xylene and p-xylene....

 and p-xylene

P-Xylene

p-Xylene is an aromatic hydrocarbon, based on benzene with two methyl substituents. The “p” stands for para, identifying the location of the methyl groups as across from one another....

. The m stands for meta

Meta- (chemistry)

In chemistry, meta is a prefix, used for systematic names in IUPAC nomenclature. It has several meanings. *In organic chemistry, meta indicates the positions of substituents in aromatic cyclic compounds...

, meaning the two methyl substituents are at locant

Locant

In organic chemistry, a locant is a figure to indicate the position of a functional group within a molecule .- Example :There are at least two isomers of the linear form of pentanone, a ketone that contains a chain of exactly five carbon atoms...

s 1 and 3 on the aromatic ring.

The major chemical use of metaxylene is in the manufacture of isophthalic acid

Isophthalic acid

Isophthalic acid is an organic compound with the formula C6H42. This colourless solid is an isomer of phthalic acid and terephthalic acid. These aromatic dicarboxylic acids are used as precursors to commercially important polymers, e.g. the fire-resistant material Nomex...

, which is used as a copolymer to alter the properties of polyethylene terephthalate

Polyethylene terephthalate

Polyethylene terephthalate , commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination...

(PET) making PET more suitable for the manufacture of soft drinks bottles. It is also used as a raw material in the manufacture of 2,4- and 2,6-xylidine as well as a range of smaller-volume chemicals.