Dielectric permittivity and loss have been measured over the frequency range 0.1 - 1000 Hz between 80 K and 300 K for side-chain and network liquid crystalline polyacrylates obtained by photopolymerization of smectic monomers. The polyacrylates were based on mixtures of chiral monofunctional monomers with a lateral nitro group attached to the outer phenyl group of the mesogen and an ester group in the mesogen and nonchiral bifunctional monomers, either with an ester group in the mesogen or with an ester group in the mesogen and a lateral nitro group, creating networks with different crosslink densities. Poled copolymers based on these monomers exhibit second-order nonlinear optical properties. Polymers based only on monomers with the chiral and nitro groups exhibited a pronounced gamma process, associated with segmental motions in the methylene spacer groups and only vague signs of the high-temperature subglass process (beta) associated with reorientation of the mesogen. The polymers with the bifunctional monomer without the nitro group exhibited clearly both gamma and beta processes. The dielectric data indicate that the ester groups in the bifunctional units undergo conventional reorientation according to the beta mechanism and that the beta process is suppressed in the pendant chains with the lateral nitro groups. The beta process involves a coordinated torsion about two bonds in the mesogen and the swept-out volume involved in the motion becomes extensive when a lateral nitro group is present.