Thermoplastic elastomers (TPEs) are composed of soft and hard segments, due to the incompatibility of these two blocks the hard one exhibit a tendency towards crystallization and the soft segment, which imparts flexibility to TPE. The properties of block poly(ether ester) (PEE) elastomers are influenced by the sequence length of soft segment and the miscibility between the soft and hard segments. Elastomers are innovative materials that have used in medical sector, packaging sector, constructions, and automobile industry. The versatility of these synthetic materials provides optimal adjustments to biomedical requirements. Since their introduction, TPEs have been used in many important applications owing to their high degree of purity, recycling ability, and cost-effectiveness. Different series of thermoplastic elastomers were synthesized using dimethyl-2,6-naphthalene dicarboxylate as hard segment, 1,4-butanediol as the chain extender, and various types of soft segments of different molecular weights (MWs), such as polycaprolactone diol (MW: 530 and 2000), poly(tetramethylene ether glycol) (MW: 1000 and 1800), polycaprolactone-block-polytetrahydrofuran-block-polycaprolactone (MW: 2000), poly(propylene glycol) bearing phosphine oxide fragment, and hyperbranched polymers. The composition of soft segment was changed from 30% to 50% with respect to the hard segment. The characteristic studies were focused to analyze the influence of the concentration and length of the soft segment content. The elastomers prepared in this study were systematically characterized using various spectroscopic studies and thermal and mechanical analyses.