Nitrile gloves are made from a synthetic polymer that exhibits rubber like characteristics when vulcanised. The polymer is made in the form of a latex or emulsion and can be used or processed very much like natural rubber latex.

There are some differences, which make this polymer unique. Unlike natural rubber, which is polyisoprene, Nitrile butadiene rubber(NBR) is copolymers of acrylonitrile and butadiene monomers.

The properties of this polymer or large molecule is thus dependent on its composition and the way in which its’ individual units or monomers are joined together. Each monomer in this composition performs a unique role and contributes to the overall balance of properties.

The term “nitrile” is used as a description of these polymers because many of the distinguishing features of this family is due to one of the monomers used, namely acrylonitrile. The presence of this monomer imparts permeation resistance characteristics to a wide range of chemicals. Due to the polar nature of acrylonitrile, these polymers are especially resistant to hydrocarbon oils, fats and solvents, unlike natural rubber, which has very poor resistance to these chemicals.

The butadiene component in the polymer contributes towards the softness, flexibility and feel of the glove. It is also responsible for participating in the vulcanisation process involving sulphur and accelerators, thereby enhancing the rubber like or elastic quality of the glove.

Thus, by controlling the composition and the formulation ingredients such as zinc oxide, sulphur, accelerators, the performance of the finished glove can be significantly altered. Features like softness, feel, modulus and solvent resistance can be controlled much more easily than in natural rubber. What this means is that nitrile can be tailored to achieve a desired performance.

The significant difference between natural rubber and nitrile latex is that natural rubber contains proteins which act as stabilizers. These proteins can cause allergic reactions since they remain in the finished glove. Nitrile lattices on the other hand do not contain any proteins but instead are stabilized by anionic surfactants. The nitrile latex can be coagulated to form a film by using calcium nitrate, just as in the case of natural latex, but without the added complication of proteins.

The other difference between natural rubber and nitrile latex is that natural rubber is a linear polymer and hence has to undergo a procuring step to enhance its strength before dipping. Nitrile polymers on the other hand are inherently cross-linked during manufacture so that little or no procuring is necessary to enhance its strength. This can be a process advantage. The degree of this cross linking can be altered by changing the process conditions or by adding agents known as chain modifiers during manufacture.

So, no matter what the ultimate end use, nitrile polymers can be significantly tailored to achieve those needs in a variety of ways. In the case of natural rubber, one is essentially limited by nature’s creation, with no room for change.