In the present study, the feasibility of increasing the productivity of suspension polymerization of vinyl chloride in batch-wise reactors was investigated using temperature variation strategy over the process time. An optimal temperature trajectory, in which the reaction temperature is higher at the beginning of the polymerization than that at the end, was obtained applying the particle swarm algorithm (PSO). Such a non-isothermal condition was implemented in a 15-liter pilot scale reactor and 33% reduction in the reaction time relative to the isothermal case with the same K value and final conversion (base case) was obtained. The molecular, morphological and the chemical properties of the produced poly (vinyl chloride) (PVC) resin were characterized. Molecular weight and polydispersity index of the nonisothermally produced PVC is the same as the equivalent isothermal polymerization. The particle size distribution would be slightly wider for nonisothermal produced PVC compared to that produced isothermally (Span non-isothermal = 1.3 and Span isothermal = 1.25). Both cold plasticizer absorption (as an index of porosity) and bulk density increases for PVC prepared by non-isothermal condition. Scanning Electron Microscopy (SEM) micrographs showed that the PVC grains prepared by variable temperatures are more spherical with smoother surfaces than those produced isothermally. The final mean primary particle size in the PVC resins prepared isothermally are greater than that in the grains formed under the nonisothermal trajectory. The grains produced in constant temperature are composed of packed, fused primary particles, whereas an agglomeration of smaller primary particles promoting the formation of porous PVC grains is observed in the nonisothermal case. The SEM image analysis of primary particles was analyzed at different conversions to estimate the conversion at which three-dimensional network is formed. The results show that applying the variable temperature accelerates networking between the primary particles inside the polymerizing monomer droplets creating nano-scale pores. For the first time, in the present work, the motionless conversion was measured experimentally and proved that this conversion is the start point of major changes in the internal morphology of PVC particles. According to the strong change of morphological properties of PVC resin around this point, a mechanism was proposed to explain how primary particles arrange at motionless conversion. There is almost no difference between networking and motionless conversion for isothermal conditions implying more likely individual growth of particles. In such circumstances individual particles preferably continue to grow until they reach the motionless point after which further polymerization fill up the discrete spaces between the individual particles. In non-isothermal conditions, on the other hand, the early aggregation of primary particles is first formed and then motionless point of primary particle clusters is achieved. the formation of numerous networks of fine primary particles inside the polymerizing monomer droplets, results in two different kinds of pores ; the interstitial pores of the primary particles inside networks and the larger free volumes or cavities (discrete zones) induced by irregular shaped three-dimensional networks of primary particles. This arrangement of primary particles causes the internal structure of PVC particles not to change significantly with increasing the conversion beyond the motionless point. As such structures would be destroyed easily by mechanical stre the processability of the final grains is much easier. Chemical analysis showed that the total number of branches, internal bonds and labile chlorine atoms per 1,000 monomer units in the chain is lower for PVC samples prepared in non-isothermal conditions. It was found that the thermal stability of non-isothermally produced PVC as characterized by dehydrochlorination rate improved for a nonisothermal grade PVC resin. The evolution of these structural defects was obtained with conversion. The Brabender plastograph data indicated that the final PVC synthesized with temperature trajectory showed lower fusion time and higher thermal stability time. The non-isothermal condition also increased the degree of fusion of the final PVC resin reflecting lower temperature/time required to process it. Keywords : Non-isothermal suspension polymerization, PVC, morphology, molecular characteristics, thermal stability.