Abstract: Novel low VOC solvent-based adhesives are provided, comprising a mixture of low vapor pressure, isomeric dimethyl-2-piperidones (DMPD) blended with (1) a non-solvent diluent, specifically, acetone (a VOC-exempt compound), or with mixtures of acetone and other known ketonic solvents such as methyl ethyl ketone (MEK), diethyl ketone (DEK), methyl propyl ketone (MPK), and methyl iso-butyl ketone (MIBK), cyclohexanone, and (2) thermoplastic PVC or CPVC resins. Omission of the resin provides a novel primer for pipes. The blended mixture yields PVC or CPVC pipe adhesives and primers that: (1) result in low VOC formulas (e.g., less than 510 g/l for PVC pipe and less than 490 g/l for CPVC pipe); (2) are very economical in the industry; (3) yield strong, quick setting, durable pipe joints that meet the required standards and performance criteria (e.g., ASTM D-2564 lap shear for PVC); (4) yield stable, low viscosity solutions that, in the case of adhesives, can be readily adjusted with thixotropes (e.g.

Abstract: CPVC adhesives for joining CPVC substrates, pipes and articles are provided which comprise (a) about 5 to about 25 wt. % CPVC resin, (b) about 20 to about 90 wt. % of a single pentanone or blends of pentanones, (c) 0 to about 20 wt. % total heterocyclic solvent, and (d) 0 to about 45 wt. % total of non-heterocyclic solvents other than component (b) (such as MEK, acetone, cyclohexanone, and so forth). The CPVC adhesive compositions of this invention permit a reduction in the content of heterocyclic solvents to be achieved while meeting performance standards applicable to CPVC pipe joining, such as hydrostatic burst strength and hydrostatic sustained pressure test.