Comparative study on properties of polypropylene-based composites reinforced with tobacco stalk fibers (unmodified / modified) from different parts of tobacco stalk

In this study, the effects of the three parts of the tobacco stalk: the xylem (TSX), husk (TSH), and core (TSC), on tobacco stalk fiber (TSF)/polypropylene (PP) composites were investigated. The effects of various types of interfacial modifiers and the number of recycled times on the properties of the composites were also explored. The results showed that the TSX reinforced PP composite exhibited better mechanical properties than those of TSH and TSC reinforced composites. The modifier improved the interfacial properties of the composites, and the tensile strengths of TSX/PP, TSH/PP and TSC/PP composites reached up to 32.8, 25.6 and 26.4 MPa in the presence of the modifier. The flexural strengths of TSX/PP, TSH/PP, and TSC/PP composites were 56.0, 46.1, and 48.7 MPa, respectively. Different parts of the tobacco stalk fiber had little effect on the thermal stability and crystallization properties of the compound material. After modification of the composites, their crystallization properties were improved, while there were no significant changes in their thermal stability. After four cycles of crushing and re-injection process, the composite material maintained good mechanical and thermal stability properties, and the interface of the compound material was tightly bonded, indicating that the prepared composites exhibited good reusability properties. Tobacco stalk fiber composite material can replace plastic or wood in decorative building materials, horticultural engineering materials, transportation packaging etc., which can obtain significant economic benefits by not only improving the broader utilization of agricultural and forestry waste but also reducing the use of plastics.