Renewable Polymers Derived from Limonene

Abstract

Renewable natural and synthetic basic substances can be used to produce biodegradable polymers. Several methods of the polymerization of terpene limonene have been evaluated. The polymerization methods evaluated are radical polymerization, cationic polymerization and thiol-ene polymerization. The free-radical polymerization of limonene with azobisisobutyronitrile (AIBN) as an initiator was carried out. The cationic polymerization of limonene was carried out using AlCl3 as a catalyst. The copolymerization of limonene with mercaptoethanol, 2-mercaptoethyl ether without an initiator and with an AIBN initiator was studied and it was also shown that polymerization can proceed spontaneously. The resulting compounds were investigated by NMR and FTIR spectroscopy. The values of the molecular weight characteristics of the samples obtained are presented, such as: number-average molecular weight, hydrodynamic radius and characteristic viscosity, depending on the method of production. The coefficients α (molecular shape) in the Mark–Kuhn–Houwink equation are determined according to the established values of the characteristic viscosity. According to the values obtained, the AC molecules in solution have parameters α 0.14 to 0.26, which corresponds to a good solvent and the molecular shape-dense coil.

Synthesis and Properties of Polystyrene Composite Material with Hazelnut Shells

“…where m 1 -weight in the air; m 2 -weight in the water; p w = 0.998 g/cm 3 -water density at 20 • C; σ = 0.0012 g/cm 3 air density.…”

“…Density g/cm 3 Melt Flow Index at 200 Hazelnut shells were used as a filler. Shell powder was obtained by grinding raw materials (hazelnut shells from the harvest of 2022) in vibratory and planetary mills.…”

“…Global trends in ecologization result in the search for new “green” materials, rapidly renewable resources with low cost, which are not toxic, and will not be inferior in properties to synthesized, artificial materials; they will contribute to maintaining the ecological balance in the world and solve the problem of their disposal [ 1 , 2 ]. “Green composites” are created by homogenizing substances based on polymeric matrices and fillers made of plant wastes (shells, husks, fibers, kernels); it is a step towards replacing synthetic fibers with natural ones in compositions [ 3 , 4 ]. Agro-industrial wastes attract special attention.…”