The prevulcanization used here posed two problems. First, a rubber coagulum was produced within 2 h of mixing prior to UV irradiation, but a much shorter mixing time may not be sufficient to homogeneously distribute the photoinitiator and the coagent in the rubber latex and within the rubber particles. This problem may be circumvented by diluting the latex prior to mixing, but this may be unacceptable for making products that require a high content of the dry rubber solids in the PVNRL. Second, the current prevulcanization treatment was carried out in vessels open to the atmosphere. As oxygen is known to rapidly react with free radicals to generate inactive products, the efficacy of the process may have been lower than if it were carried out in a closed reactor and without any dissolved oxygen in the rubber latex. Potentially, all dissolved oxygen in the latex can be removed by purging it with an inert gas such as nitrogen.