The effect of partial replacement of maleic anhydride by itaconic acid in sebacic acid-based unsaturated polyester on its various properties.

Unsaturated Polyester Resin (UPR) is widely synthesized using non-renewable resources. However, the use of bio-based material is a need in today's world to ensure sustainable development. The presented investigation defines the use of bio-based itaconic acid (IA) as a replacement of conventional maleic anhydride (MAn) in UPR. The reactions of IA and MAn at varying ratios in the presence of sebacic acid (SA) and neopentyl glycol (NPG) were carried out. The objective was to investigate the effects of such replacement to bring more insight into structure–property relations. The synthesized resins were characterized by Fourier Transforms Infrared Spectroscopy (FTIR), Rheology, Gel Permeation Chromatography (GPC),Thermo-mechanical and other physical properties including viscosity and density. The addition of IA as a complete replacement to MAn increased the peak exotherm to 500C as opposed to 380C for polyester based on MAn alone. This led to quicker gelation and curing. Molecular weight Mn and Mw were found to be reduced to around 66% and 47% respectively leading to reduced viscosity. [ABSTRACT FROM AUTHOR]