Effect of field natural rubber latex with different ammonia contents and storage period on physical properties of latex concentrate, stability of skim latex and dipped film

Abstract

The effect of ammonia treatment in field natural rubber (NR) latex with different storage period time on the properties of concentrated NR latex and stability of skim latex was investigated. Fresh NR latex was treated with various ammonia contents such as 0.35, 0.60 and 0.80% w/w, and then they were centrifuged to get the concentrated NR latex with 60% dry rubber content (DRC) containing 0.16, 0.18 and 0.25% w/w, respectively and skim NR latex with roughly 5% DRC containing 0.42, 0.60 and 0.80% w/w, respectively. The effect of storage times with ∼0, 15, 30 and 45 days for concentrated NR latex with different ammonia contents on their properties such as alkalinity, magnesium content and viscosity was observed. It was found that generally, magnesium content in field NR latex and latex concentrate decreased with storage period times. The alkalinity content in both concentrated NR and skim latex increased with increasing ammonia content in field latex. The viscosity of concentrated NR latex increased as a function of storage period time of field NR latex. The stability of skim latex depends on storage period time of field NR latex with different ammonias. The tensile strength of dipped films obtained from field NR latex with 0.80% w/w of ammonia was dependent on storage period time of field NR latex.