Although closely related to polystyrene, poly(divinylbenzene) (PDVB) has found limited utility due to the difficulties associated with its synthesis. As a highly cross linked polymer, PDVB is infusible and insoluble and thus nearly impossible to shape into films by either melt or solvent based processes. Here, we report the initiated chemical vapor deposition (iCVD) of nearly stress-free, highly transparent, free-standing films of PDVB up to 25,mu m thick. Films initially grow under tensile intrinsic stress but become more compressive with thickness and eventually converge to zero stress values once they reach >= 10 mu m in thickness. Upon initial heating, the evaporative loss of unreacted monomer left in the polymer matrix induces between 35 and 45 MPa of tensile stress in stress and film expansion behaviors. We estimate the degree of to 300 degrees C) and mechanical stiffness (Young's modulus of 5.2 iCVD PDVB an excellent candidate for protective coatings in the films. Afterward, subsequent heating cycles induce reversible cross-linking to be 44%, resulting in high thermal stability (up GPa). The low stress combined with high cross-linking makes harsh environments.