Tensile Response of Plasticized Polyvinyl Chloride Containing Thermally Modified Rice Starch and Commercial Glycerol Monostearate
B. F. Mukhiddinov
Navoi State University of Mining and Technologies, 76V Galaba Avenue, Navoi 210100, Uzbekistan.
H. Y. Istamov
*
Navoi State University of Mining and Technologies, 76V Galaba Avenue, Navoi 210100, Uzbekistan.
I. I. Jurayev
Navoi State University of Mining and Technologies, 76V Galaba Avenue, Navoi 210100, Uzbekistan.
*Author to whom correspondence should be addressed.
Abstract
Background: Incorporating starch into plasticised polyvinyl chloride (PVC) can increase the renewable constituent fraction but may reduce tensile strength, deformability, and stiffness. Commercial glycerol monostearate may influence these properties through formulation-related effects. However, the tensile response of plasticised PVC containing thermally modified rice starch with and without glycerol monostearate remains insufficiently characterised.
Aims: To compare tensile properties of plasticised polyvinyl chloride containing thermally modified rice starch, with and without commercial glycerol monostearate.
Study Design: A laboratory formulation study with one unfilled control, fourteen starch-containing formulations and five tensile specimens per formulation.
Place and Duration of Study: Navoi State University of Mining and Technologies, Navoi, Uzbekistan, 2023–2025.
Methodology: Formulations with 5–30 wt% starch without the additive and 5–55 wt% starch with 5 wt% commercial glycerol monostearate (GMS-40) were extruded and compression moulded. Mean stress at break, elongation and reported Young’s modulus were compared descriptively. The additive replaced an equal mass of the plasticised matrix.
Results: At matched starch contents, additive-containing formulations showed mean stress at break, elongation and modulus values 12.4–18.8%, 19.0–26.6% and 9.8–16.5% higher, respectively. At 30 wt% starch, stress at break increased from 1.76 to 2.09 MPa and elongation from 52.39% to 66.32%. Replicate dispersion is not reported, precluding significance testing.
Conclusion: GMS-40 was associated with partial recovery of the reported tensile properties at matched starch loading. The comparison describes a combined formulation effect and does not establish an optimum additive concentration or an interfacial mechanism.
Keywords: Polyvinyl chloride, thermally modified rice starch, glycerol monostearate, tensile stress at break, elongation at break, Young’s modulus