A Novel Accelerator System for Synthetic Polyisoprene
|Date Published||January 1, 2004|
Synthetic polyisoprene latex is chemically very similar to natural rubber latex. However, the physical properties of the synthetic ‘vulcanized’ films have never equaled those of the natural product. Natural latex films can be cured quickly (about 15 to 20 minutes) at low temperatures (~90 to 100ºC) with a variety of accelerators to produce tensile strengths normally between 25 and 35 MPa. Unfortunately, synthetic polyisoprene has not been so easy to cure. This is mostly due to the fact that, until now, a suitable accelerator system to promote sulfur cross-linking has not been available to the latex industry at large. Regardless of the accelerator system, synthetic polyisoprene films rarely exceeded a tensile strength of 10MPa. This paper will describe a new accelerator system that is able to produce synthetic polyisoprene films with tensile strengths between 20 and 35 MPa at low curing temperature. Additionally, this paper will offer recommendations for the cure system to be used while making the films. Finally, this paper will investigate the use of this new accelerator system in natural rubber latex and carboxylated acrylonitrile.