Abstract

The research aim is to develop alternative cost-effective poly (vinyl chloride) PVC formulation that possesses good mechanical properties, resistant to microbial attack, with low volatile organic compounds (VOC's) emission, as well as to explore a market for lignin, an abundant natural polymer, obtained as a by-product of paper making. One of the main applications of plasticized PVC for building industry is the production of flooring. Normally in the manufacture industry of the PVC flooring di-ethyl-hexyl-phthalate (DEHP), commercially known as DOP is used as a plasticizer to facilitate the processing of PVC. DOP is environmental pollutant due to its biodegradability that consequently releases VOC's; considering this hazard, the introduction of other biopolymers and other additives in PVC formulation could contribute to a safer and healthier environment. DOP has been used in this research for comparative purpose only. Series of plasticized PVC formulations were prepared with different types of plasticizers namely: Di-octyl phthalate (DOP), Diethylene glycol dibenzoate (Benzoflex 2-45), Tricresyl phosphate (Lindol) and Alkyl sulfonic acid phenyl ester (Mesamoll). Meanwhile, the role of lignin within the mixtures was evaluated, as part of the PVC was replaced with different lignins namely Organosolv, Indulin and Tomlinite (20 phr of PVC). The new proposed alternative flooring material was prepared by melt mixing and compression molding, and tested to evaluate its processibility, thermal properties, mechanical properties (i.e., Young's modulus, tensile strength at break and yield, elongation at break) as well as its morphology. In addition, the different formulations resistance to fungi attack was studied as a function of the samples weight loss, and their fungal growth was evaluated visually. Also, the impact of this growth on the mechanical and thermal properties of the different presented formulations was studied to evaluate their bio-deterioration. Moreover, considering the introduction of new formulations, their ageing behavior due to inherent instability of the amorphous glassy state, known as volume recovery or structural relaxation is studied. Finally, the primary emissions (i.e., free non-bound VOC's, which generally have low molecular weight) of VOC's are identified and quantified