IT'S A LATEX SUBSTITUTE, ONLY BETTER

Nitrile gloves are made from a synthetic polymer exhibiting rubber-like characteristics when vulcanized.  The polymer is manufactured as solids and emulsion, and can be processed like natural rubber latex.

IT'S A DESIGNER POLYMER

Compared to natural rubber, softness, feel, modulus, solvent resistance, and tensile and tear-strengths are designed easily in nitrile production.  Unlike natural rubber, which is polyisoprene, nitrile polymers consist of three monomers: acrylonitrile, butadiene, and any one of many carboxylic acids.  Performance features of the finished glove are controlled through the use of these monomers and their associated formulation ingredients, such as zinc oxide, sulfur, and process accelerators.

Here is what each of the monomers contributes to the finished glove:

• Nitrile's namesake monomer is acrylonitrile.  Due to its polar molecular structure, acrylonitrile generally provides permeation to a variety of solvents and other chemicals.  Within nitrile polymers, acrylonitrile contributes resistance to hydrocarbon oils, fats, and solvents.  In contrast, natural rubber has very poor resistance to these chemicals.
• Along with sulfur and chemical accelerators used in the vulcanization process, butadiene enhances elasticity.  In the finished glove, this polymer contributes softness, flexibility, and rubber-like feel.
• Interacting with zinc oxide to create ionic bonds during compound formulation, carboxylic acids contribute tensile strength and abrasion- and tear resistance in the finished glove.  They also enhance solvent resistance, a characteristic absent in natural rubber because it lacks any carboxyl functionality.

IT'S EASIER TO PRODUCE

Nitrile has production process advantages over natural rubber, too.  Natural rubber is linear polymer which must be precured to strengthen it before dipping.  In comparison, nitrile polymers are inherently crosslinked so that little or no precuring is necessary to enhance their strength.  The degree of crosslinking is altered through process conditions and the addition of chemical chain modifiers.

PROTEIN FREE, ALLERGY FREE

Another important difference between the two materials is the fact that natural rubber contains proteins, which act as stabilizers.  Proteins remain in the finished glove, and thus, cause allergic reactions in sensitive glove users.  Contrast this to nitrile, which contains no proteins because it is stabilized with anionic surfactants.

ADVANTAGES FOR THE SEMICONDUCTOR INDUSTRY

A valuable feature to the semiconductor industry is the ability of nitrile gloves to more effectively dissipate electrostatic charges.  Plus, due to their better abrasion resistance, they slough off significantly fewer particles, which contaminate critical manufacturing environments.