Removal of water extractable proteins from concentrated natural rubber latex by eggshells

The protein allergy caused by latex products has become an acute problem to human and animals; sweat removes proteins, which then comes in contact with the skin causing the sensitization or allergic reactions. Eggshells from chickens, ducks, and birds are potential starting materials to be used in reducing the water extractable proteins in concentrated natural rubber latex (NRL). The pyrolysis of eggshells at 900°C for 2 h transforms the crystal structure of calcium carbonate into calcium oxide with a high purity, creates a small and uniform particle size, a suitable specific surface area, and an average pore diameter that is suitable for reacting with hydrochloric acid to obtain calcium chloride (CaCl ₂ ). The additions of CaCl ₂ solution and sodium dodecyl sulphate into concentrated NRL are shown and reported here to extract effectively the proteins from the NRL film.