TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: (I) comprises a silane coupling agent. (I) is a nanocomposite material. Preferred Components: The rubber is natural rubber, styrene-butadiene rubber, ethylene propylene diene rubber, halogenated butyl rubber, butadiene rubber or silicone rubbers. At least 10 mole% of the total amount of charge-balancing ions in the layered double hydroxide comprises hydroxyl anions. The layered double hydroxide comprises a charge-balancing organic anion having a first functional group and a second functional group, where at least part of the organic anions is chemically linked to the rubber through the second functional group. The coupling agent has at least alkoxysilane group and at least one reactive group, where the alkoxysilane group is chemically linked to the layered double hydroxide and the reactive group is chemically linked to the rubber. EXAMPLE - Zolitho 40 (RTM: Magnesium oxide) (68.2 g) and Alumill F505 (RTM: Aluminium hydroxide) (43.6 g) were mixed in demineralized water (840 g) and ground to an average particle size of 2.5 mu m. The slurry was fed to an oil-heated autoclave equipped with a high-speed stirrer and heated to 80 degrees C. Then 132 g of a 50/50 mixture by weight of Kortacid PH05 (RTM: Blend of palmitic acid and stearic acid) and stabilized rosin were added to the autoclave over 15 minutes. Before addition, the acid mixture was heated to 80 degrees C. After the acid addition, the autoclave was closed and heated to 170 degrees C and kept at that temperature for 1 hour. Then the autoclave was cooled to 40 degrees C and the resulting slurry was removed. The slurry was then centrifuged at 2000 rpm for 10 minutes. The liquid was poured off and the solids were dried under vacuum in an oven overnight at 80 degrees C to form a layered double hydroxide (LDH), where 20 mole% of the charge-balancing anions in the resulting LDH were hydroxyl anions. The LDH was mixed with natural rubber (standard Malaysian rubber with grade CV (SMR-CV)) in a 50/50 masterbatch on a two-roll mill at 40 degrees C. Then rest of the mixing procedure was done in a 1.6 l Banbury with a load factor of 70%, by: mastication of natural rubber for 1 minute at a starting temperature of 60 degrees C; addition of the 50/50 masterbatch and mixing for 5 minutes; sweeping for 1 minute; and dumping, where the final temperature of the mixture was 140 degrees C maximum. After cooling, the vulcanization ingredients were added on a two-roll mill to obtain a composite material containing (in parts per hundred rubber): SMR-CV (100); LDH (10); n-cyclohexyl-2-benzothiazole sulfenamide (1.5); and sulfur (1.5).