Quality improvement of radiation vulcanized natural rubber latex by addition of polyvinyl alcohol and centrifugation

Abstract

Effect of polyvinyl alcohol(PVA)on extractable soluble protein content,and on mechanical and physical properties of radiation vulcanized natural rubber latex(RVNRL)was studied with the view of improving properties of RVNR latex.Concentrated natural rubber latex was irradiated at the rate of 10 kgy/h for 2hrs in the presence of 5 phr of n-BA and 0.5 phr of KOH.PVA solution was added to the RVNR latex at three different stages and different time periods were used for leaching to find out the most suitable process to produce soluble protein less RVNR latex.present results indicate that combined treatments of PLVA addition and centrifugation foollowed by leaching were more effective compared to single treatmemt to reduce soluble protein content in RVNR latex films.It could be further observed that,the tear strength was increased whereas tensile strength and tackiness were decreased with PVA concentration.However when the PVA incorporated RVNRL was centrifuged,tensile and tear strenght were not changed up to 2 phr of PVA.Fourier Transrorm infrared slpectrophotometer (FTIR)measurements showed that whem PVA added RVNRL was centrifuged,most of the PVA could be removed with the serum phase,According to the Horixontal Attenuated Total reflectance(HATR)measurements ,PVA concentration on the upper and lower surfaces of the latex films (I.E.the exposed and unexposed surfaces of the films whem drying )was not equal.