Investigation of Maillard reaction in natural rubber (NR) latex was carried out using two reducing sugars, glucose and ribose. Both reducing sugars together with a 1:1 mixture were added as 5 wt% solution to concentrated NR latex preserved with ammonia in a 1:1 ratio and preheated at 27, 70 and 90 °C for 2 h. The changes in the latex due to the reaction were characterised using pH and L values for 216 h (9 days). Cast latex films were then prepared and investigated for their swelling index (SI), gel content and tensile properties. Results obtained showed reduction in both pH and L values with time for the latexes with reducing sugars indicating progress of the Maillard reaction. For the Maillard reacted films, SI reduced whereas gel content, tensile stress and tensile strength increased. However, no significant changes were observed for the elongation at break of the reacted samples compared to the unreacted samples. Increasing the preheating temperature of the latex and reducing sugar mixtures to 70 and 90 °C from 27 °C increased the Maillard reaction which further improved the film properties. Although both reducing sugars improved the film properties, the improvements brought by reacting NR latex with ribose were more significant compared to reacting NR latex with glucose. From the current findings, it is evident that reducing sugars could be used to enhance the physical properties of natural rubber latex films. This technique will benefit the latex industry as it is environmentally friendly, easily applicable and cheaper compared to currently available techniques.

使用两种还原糖，葡萄糖和核糖对天然橡胶（NR）胶乳中的美拉德反应进行了研究。将两种还原糖与1：1混合物一起作为5 wt％溶液添加到以1：1比例用氨气保存的浓缩NR胶乳中，并在27、70和90°C下预热2 h。使用pH和L值（216天（9天））表征由于反应引起的胶乳变化。然后制备流延胶乳薄膜并研究其溶胀指数（SI），凝胶含量和拉伸性能。获得的结果表明pH和L均降低含还原糖的胶乳随时间变化的数值表明美拉德反应的进行。对于美拉德反应膜，SI降低，而凝胶含量，拉伸应力和拉伸强度提高。然而，与未反应的样品相比，未观察到反应样品的断裂伸长率有显着变化。将胶乳的预热温度提高和将糖混合物的温度从27°C降低至70°C和90°C会增加美拉德反应，从而进一步改善了薄膜的性能。尽管两种还原糖均改善了膜的性能，但与将NR乳胶与葡萄糖反应相比，NR乳胶与核糖反应所带来的改进更为显着。根据目前的发现，很明显还原糖可以用来增强天然橡胶胶乳薄膜的物理性能。