NOVELTY - Continuous process for preparing a thermoplastic elastomer composition comprises: (a) providing a thermoplastic resin; (b) providing a non-halogenated elastomer comprising repeating units derived from at least one 4-7C isomonoolefin monomer and a 4-16C multiolefin monomer; (c) providing an unsaturated 4-16C carboxylic acid derivative; (d) mixing the thermoplastic resin, the elastomer and the unsaturated carboxylic acid derivative to create a thermoplastic elastomer composition; and (e) mixing a curing system to dynamically vulcanize the thermoplastic elastomer.    USE - The process is useful for preparing a thermoplastic elastomer composition (claimed), which is useful in forming article such as tire curing bladders, tire innerliners, tire innertubes, air sleeves, a hose or a hose component in multilayer hoses, air spring bladders, molded goods, cable housing, condenser caps, medical components, such as components of biomedical devices or pharmaceutical devices (e.g. stoppers in medicine-containing vials, and plungers in syringes) and/or in fuel cell components, such as seals.    ADVANTAGE - The process enables addition of materials including curatives, compatibilizers, extenders, and plasticizers to provide desired physical properties to the thermoplastic elastomer composition. The composition can be produced with improved elongation and ultimate tensile strength in an economic and eco-friendly manner.    DETAILED DESCRIPTION - Continuous process for preparing a thermoplastic elastomer composition comprises: (a) providing a thermoplastic resin; (b) providing a non-halogenated elastomer comprising repeating units derived from at least one 4-7C isomonoolefin monomer and at least 3.5 mole% of a 4-16C multiolefin monomer; (c) providing an unsaturated 4-16C carboxylic acid derivative; (d) mixing the thermoplastic resin, the elastomer and the unsaturated carboxylic acid derivative in a first stage of a continuous mixer to create a thermoplastic elastomer composition comprising the carboxylic acid derivative graft; and (e) mixing in a second stage of the continuous mixer a curing system suitable for use with non-halogenated elastomers to dynamically vulcanize the thermoplastic elastomer.