INFORM November/December 2025

inform November/December 2025, Vol. 36 (10) • 21

danol and cardol at different ratios. To valorize these fractions effectively, this study centers on their potential utilization as starting materials for PVC plasticizers. Firstly, the study focused on different alkyl chain lengths of ester on CNSL mixtures to determine the optimum chain length for plasticizing properties. Then a more detailed study was carried out on different cardanol–cardol natural mixtures at different ratios. The chemical composition of these plasti cizers was analyzed through 1 H NMR spectroscopy. Then, PVC films were subjected to comprehensive analysis to assess their rheological, mechanical, thermal, and leaching characteristics. SYNTHESIS OF CNSL ESTERS To design an optimal plasticizer, ester groups are gener ally added to increase cohesive units and improve stability between plasticizer and PVC. This modification enhances dipo lar forces, thereby improving compatibility between the plasti cizer and PVC. Additionally, the incorporation of dangling long chains enhances polymer chain mobility. It is worth noting that literature has already described acetylated cardanol deriva tives, such as C2, which bear short alkyl chains and exhibit a positive plasticizing effect on PVC. But as far as we know, only our previous work focuses on cardol derivatives and depicts its potential use in plasticizer formulation. It should also be noted

that cardanol-C18:1 has no endocrine-disrupting effect, and neither do cardanol-C2 and cardol-C2, except they exhibit an agonist effect at high concentrations. After characterization of CNSL derivatives C2, C8, and C18:1 presented previously, these plasticizers were applied to the production of PVC films, and their plasticizing efficien cies were compared to widely used commercial phthalates like DEHP and DINP. While numerous studies have compared plas ticizers with only one of these references, incorporating both reference plasticizers into the analysis, along with biobased vegetable oils like ESBO and ELO, appears advantageous for standardization and ease of comparison. The study examined the mechanical and thermal properties of various PVC films plasticized with CNSL esters. PVC PLASTISOLS CONTAINING CNSL-C2 ESTERS The apparent viscosity represents the resistance to shear of a fluid under applied forces, typically measured in response to varying shear rates. At lower shear rates, the viscosity is rel atively high, suggesting resistance to flow. As the shear rate increases, the viscosity decreases until it reaches a minimum point. This behavior may be attributed to various factors such as structural changes, shear thinning, or shear thickening prop erties of the material. In addition, the observed increase in

Elongation at break (a) and Young’s modulus (b) of plasticized PVC films with 43 phr of plasticizers. Traction curves (c) of PVC films plasticized with A_B 80_20 derivatives. TGA isothermal (d) at 200 °C of plasticized PVC films. Source: Gartili, A., et al. , JAOCS , 102, 8, 1141, 2025.