Natural rubber latex or commonly abbreviated as NRL is a liquid milky sap which was tapped from Hevea brasiliensis, trees which were originally from region of South America. It has rubber content of 33% which was suspended in 65% of water and contained 2% of protein. NRL is chemically known as 1,4-cis-polyisoprene. Production of NRL has grown rapidly and its main used was as manufacturing of gloves . In order to improve mechanical properties of these products, several studies had been done using silica, calcium carbonate, montmorillonite (MMT), kaolin as fillers to reinforce vulcanizates [2-5].
Kaolin is one of clay material that is widely used in certain field of applications. It is categorized as minerals with chemical composition Al2Si2O5(OH)4 and has silicate mineral layer with one of tetrahedral sheet joined to one of octahedral sheet via oxygen atom. Kaolinites have high shrink-swell and low cation exchange capacity. They have varieties of chemical composition depend on physical and chemical changes to environment where they were discovered. The main fact of kaolin utilization in industry is due to its surface reactivity and properties which were able to be modified . From previous study done by Yahaya et al, it is observed that kaolin could be treated further by modifying its surface with oil tea seed results in organo modified kaolin .
In this study the kaolin is modified by alkanolamide, derived from oleochemicals materials, Refinery Bleach Deodorant Palm Stearin (RBDPS). It is expected that alkanolamide could role as compatibilizer between kaolin and NRL matrix since alkanolamide is usually used as non-ionic surfactants in the household and cosmetic industries . Keamkumay et al in his research used octadecylamine which is primary amine surfactant can modify MMT surface . This shows that materials based surfactant are potential to be used as modifying agent in mineral clays. Meanwhile, the conventional compatibilizer in NRL system is polyvinylpyrrolidone (PVP) which is a common polymer material used as stabilizing agents in aqueous solution. PVP was used to observe and to compare the mechanical properties of vulcanizates with one modified by alkanolamide. Leaching is one method commonly used to improve the mechanical properties of NRL products hence the objective of this study is to observe the effect of leaching treatment on mechanical properties of NRL products filled with kaolin modified alkanolamide and kaolin modified PVP.
High Ammonia Latex with 60% of total dry content was obtained from local market. Industrial grade of kaolin as fillers with size of 300 mesh; polyvinylpyrrolidone (PVP) as comparing compatibilizer; potassium hydroxide (KOH), sodium hydroxide (NaOH), acetic acid (CH3COOH), calcium nitrate (Ca(NO3)2), toluene (C6H5CH3) and chloroform (CHCl3) were laboratory grade (MERCK) used as supporting chemical substances in this study were purchased from CV....