**2.3 Modifications and properties of recycling of virgin and waste PVC**

The increase in commercial vehicles and road usage with construction resulted to increase in demand of bitumen for pavement and road construction. Yet, the durability of the bitumen depends on appropriate binder for enhancement of performance of bitumen. The use of little quantity of virgin thermoplastics provides a reasonable performance with bitumen but is uneconomical compared with only bitumen. The utilization of waste PVC for effective performance as bitumen binder in pavement and road construction products seems to be interesting because of its low cost and because it is one of the abundant thermoplastics that causes environmental threat [50]. The applications of PVC have been reported to hinder and be not suitable for many applications because of incompatibility as a result of many factors [51]. PVC possesses high melting points which hindered the mixing, and it is impractical to make any further attempts to incorporate it in some applications like bitumen road construction. Recycled LDPE/PVC blends have been modified using EPDM as effective toughening, compatibilizer, and dispersant agent in applications. Recyclability of PVC waste can be achieved mechanically without modifications or use of new plasticizer since the separation of other mixed plastics is possible through triboelectrostatic technology [50, 52]. The technology of triboelectrostatics depends on the ability of polymer to the electron loses or gains because electrons gains and charges negatively may be as a result of higher affinity of polymers, whereas loss of electrons and positively charge may be attributed to polymer with the lower affinity. Because of high electronegativity of chloride ions, it can mix with many polymers such as PET, PP, PS, and PE with enhanced properties as reported by Hamad et al. [50]. The use of wood fillers or fibers as natural modifiers have been reported to improve mechanical properties of recycled PCV rather the recyclability [53], and slightly reduction in mechanical (tensile, flexural, hardness and impact) and structural properties (i.e., decrease in molecular weight due to molecular chain scission caused by shear stress involved in reprocessing) [54]. The reduction in properties exists because of incompatibility or poor intermolecular interaction which can be modified by surface techniques.
