The most common types of insulation are Expanded and extruded polystyrene are commonly known as EPS and XPS, respectively; for more than 50 years, both types have been manufactured with the brominated flame retardant hexabromocyclododecane (HBCDD). As soon as HBCDD was Stockholm Convention controlled it because it is a substance of high concern in addition to European REACh laws. As a result, HBCDD insulation is not recommended. Insulation manufactured with HBCDD-equipped EPS or XPS is being phased out, and its waste cannot further undergo cutting-edge mechanical recycling.Most of the EPS and XPS built before the ban on HBCDDs are still in service. Research is being conducted to find more complex methods of reusing insulating material. Polystyrene from insulation is dissolved in a solvent and recycled in this research. Waste and eliminate both the co-dissolved HBCDD and the insoluble waste components. Due to this procedure, the study examines the mechanical characteristics of regenerated PS and the efficacy of HBCDD removal.Inorganic waste and other non-target polymers were safely separated, and the results indicated an overall increase in purity, removing more than 99.6 per cent of the HBCDD that was there to begin with. Recycled polystyrene's mechanical characteristics are in the typical quantity of virgin general-use PS, provided that residual solvents are removed if the recycled polymer has a residual solvent level of less than 0.1%, and then it may be used.

In this study, modification of poly(adipic anhydride) through branching its chains was carried out via melt condensation polymerization with D-mannitol. The percentage of mannitol was varied (3, 4, 5, 10, 15, and 20 Wt.%) and the resulting copolymers were purified and characterized by FT-IR and ¹³C-NMR. These analyses indicated that linear chains of poly(adipic anhydride) can react with strong nucleophiles and dissociate to produce highly branched poly(adipic anhydride-co-mannitol adipate) which confirms the validity of the proposed mechanism. The copolymer’s molecular weight characteristics have been also examined using GPC analysis. Thermal properties of copolymers were also investigated using TGA, DTG, and DCS analyses. TGA/DTG revealed that the thermal degradation of copolymers proceeds in multi-stage decomposition, whereas the shift and pattern change of the melting point peak of DSC curves can identify the weight percentage of mannitol for homogenous copolymers. Two non-isothermal models, the Flynn–Wall–Ozawa and Kissinger methods, have been also employed to analyze thermogravimetric data collected from the thermal decomposition of the copolymers and found that Flynn–Wall–Ozawa method provides better results with R² correlation up to 99.3%. The activation energy in the region of T_max was determined and found that an increase in mannitol contents in copolymer has a positive impact on its thermal stability.