Low dielectric photopatternable materials have aroused much interest owing to their potential application as alternatives of conventional photoresists. Although a number of photosensitive groups have been established to construct photopatternable materials for many years, it is still a challenge to introduce them into polymer chains via a facile and control polymerization technique, such as living free radical polymerization. In this work, on the basis of the photoactive silaycyclobutene moiety, a new monomer, 1-methyl-1-(4-vinylphenyl) silacyclobutane (1-MVPSCB), was synthesized and demonstrated successful to conduct atom transfer radical polymerization (ATRP). Subsequently, the copolymerization of 1-MVPSCB with 4-vinylbenzocyclobutene (4-VBCB) and styrene produced a kind of benzocyclobutene/silacyclobutane double-crosslinked polymer (BS-DCP) with controlled benzocyclobutene/silacyclobutane ratios and low polydispersity index. Owing to the UV/thermally dual crosslinked structure, BS-DCP possesses photapatternability, high dimensional stability and low dielectric constant (2.37 at 10 MHz). These properties make BS-DCP a potential photoresist that could be directly used as interconnected dielectrics. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1920-1928