Side-chain crystallizable comb-like polymers can be used as polymeric thermal energy-storage materials. Diethylene glycol hexadecyl ether acrylate (C16E2AA) was synthesized with sodium alkoxide using diethylene glycol hexadecyl ether (C16E2) and acryloyl chloride as reactants. C16E2AA was prepared by free radical polymerization to form a comb-like polymeric phase change material, poly(diethylene glycol hexadecyl ether acrylate) (PC16E2AA). A series of sheath/core composite submicron fibers were coaxially electrospun using PC16E2AA as the core and poly(acrylonitrile-co-vinylidene chloride) as the sheath. Results indicate that C16E2AA and PC16E2AA were synthesized in high yield. The average molecular weight and polydispersity index of PC16E2AA were 29,800 g/mol and 3.17, respectively. PC16E2AA melted at 33.8 C and crystallized at 25.8 C. The melting and crystallization enthalpy for PC16E2AA were 90 and 85 J/g, respectively. PC16E2AA was thermally stable below 326 C. Coaxial submicron fibers with smooth surface and average diameter ranging from 341 to 371 nm were electrospun. The optimum feed rate of the sheath and core components for fabricating thermo-regulated submicron fibers with high enthalpies were 0.125 and 0.375 mL/h, respectively. The fibers can absorb 50 J/g at approximately 37 C and release 48 J/g of heat at approximately 32 C.Phase change materials (PCMs) are reusable energystorage materials that can absorb significant amounts of energy as latent heat and release it into the surroundings during a solid-liquid or solid-solid phase change over a defined temperature range. 1 PCMs have been used for energy-saving buildings, 2,3 solar energy storage, 4 waste heat recycling, 5 both smart fibers and fabrics 6,7 and garment cooling. 8 The research on traditional solid-liquid organic PCMs (such as paraffin waxes, fatty alcohols and aliphatic polyesters) has attracted increasing attention. 1 However, severe supercooling and leakage into the surrounding environment during solid-liquid transitions limit their practical application. 6,9 PCMs can be encapsulated to obtain microencapsulated phase change materials (microPCMs) or nanoencapsulated phase change materials (nanoPCMs) that remain in the solid state forever. Leakage of PCMs during the phase change process can be decreased when polymers such as polyethylene glycol, aliphatic polyesters and block copolymers 10,11 are used as PCMs. However, few materials that satisfy the demands are available. The fabrication, structure and properties of a series of comb-like polymers with crystallizable side chains have been investigated for decades. 12-16 However, these polymers are seldom used as polymeric phase change materials (PPCMs) because the temperature range between the melting and crystallization temperature for some PPCMs is too high or the enthalpy too low to be Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber,