Low decomposition temperature (<200^oC) template polymers that decompose into gaseous products have been used as templating materials in the formation of air-cavities and porous dielectrics. It is especially important for the sacrificial, templating polymer to decompose cleanly to gaseous products at a specific temperature, which is compatible with the other materials present, especially the dielectric superstructure surrounding the sacrificial material. It is also important for the sacrificial polymer to leave little or no residue so that undesirable materials are not formed during the process.  One method of producing a low-temperature sacrificial material is the use of a low ceiling temperature polymer. Above the ceiling temperature, the polymer reverts back to monomers.  A polymer with a low ceiling temperature can rapidly depolymerization back to monomer and vaporize, if the monomer vapor pressure is suitably high at room temperature (>10 Torr).  This work focuses on the synthesis and decomposition of low ceiling temperature polyaldehydes using high vapor pressure monomers.  Polyphthalaldehyde could be used as the template polymer for creating air-gaps and porous dielectrics. Polyphthalaldehyde has a moderate decomposition temperature of 125^oC and a moderate vapor pressure.  Copolymers of aldehydes are of interest because the vapor pressure of the sacrificial polymer decomposition products can be increased. Polyaldehyde copolymers were synthesized with the goal of increasing the thermal decomposition temperature and increase the evaporation rate of the decomposition products.  A random copolymer of phthalaldehyde and butyraldehyde raised the 50 percent decomposition temperature of the polyaldehyde by 25^oC when compared to the phthalaldehyde.  homopolymer.  Even a small amount of the higher vapor pressure monomer, butyraldehyde, increased the evaporation rate substantially.