The vertical alignment mode is widely applied in liquid crystal (LC) devices but exhibits a slow response time. To induce fast switching of LCs, bifunctional reactive monomers (RMs) were mixed with polyimide (PI). Two types of RMs were used: RMs with alkyl spacers and alkyl-free RMs. The mixture of RMs and PI was treated with ultraviolet light under an electric field to induce the pre-tilted LC alignment. The newly fabricated alignment layers exhibited low threshold voltages and fast response times compared to pure PI. Furthermore, the alkyl-free monomers induced a faster switching of the LCs than RMs with alkyl spacers.