We synthesized a series of poly(dialkyl 1-viny-3,5isophthalate) (P-3,P-5-n, n is the number of carbons on alkyl group, n = 4-18), wherein the polyethylene backbone is jacketed by the isophthalate side chains. The phase behaviors of P-3,P-5-n were investigated by using various techniques including thermal analysis, polarized light microscopy, and X-ray diffraction. It is identified that with n >= 8 the P-3,P-5-n samples form the hexagonal columnar phase (Phi(H)). Furthermore, P-3,P-5-16 and P-3,P-5-18 can exhibit a four-column hexagonal superlattice (Phi(S)(H)), wherein one column is frustrated. After the alkyl tails are fully melted or crystallized, the Phi(S)(H) degrades into the conventional Phi(H) phase. For the Phi(H) of P-3,P-5-n observed, the cross section area of the column (S) increases linearly with n, S = 1.97 + 0.52n (nm(2)). The number of repeating units (Z(rep)) required to be packed in the 0.44 nm thick column stratum is 4. Compared with poly(dialkyl 1-vinyl-2,5-terephthalate) (P-2,P-5-n), which is the isomer of P-3,P-5-n and can form the Phi(H) phase based on the parallel packing of a "single-chain column", P-3,P-5-n possesses the intercept and slope of the linear function of S vs n and the Z(rep) value nearly twice that found for P-2,P-5-n. We propose that P-3,P-5-n can self-organize into the column containing two chains laterally associated together. Namely, P-3,P-5-n takes the "double-chain column" rather than the "single-chain column" as the building block for the Phi(H) phase.