An efficient cold-resistant strategy: Synthesis and application of green cold-resistant bio-based plasticizer for poly(vinyl chloride)

1-Methyl-4-R-1,2,4-triazolium (R = -CH2CH2OCH3, -CH2COOCH2CH3)-Based Ionic Liquids as Plasticizers for Solid Propellants

In this paper, a series of energetic ionic liquid plasticizers of 1-methyl-4-methoxyethyl-1,2,4-triazolium chloride (1), 1-methyl-4-methoxyethyl-1,2,4-triazolium bis(trifluoromethylsulfonyl)imide (1a), 1-methyl-4-methoxyethyl-1,2,4-triazolium nitrate (1b), 1-methyl-4-ethyl acetate-1,2,4-triazolium chloride (2), 1-methyl-4-ethyl acetate-1,2,4-triazolium bis(trifluoromethylsulfonyl)imide (2a), and 1-methyl-4-ethyl acetate-1,2,4-triazolium nitrate (2b) were synthesized and characterized. The results show that compounds 1a, 1b, 2a, and 2b have lower melting points (T_m, -72.60 to -32.67 °C) and good thermal stability (T_d, 161-348 °C) and are suitable as plasticizers for hydroxyl-terminated polybutadiene (HTPB) curing systems. Among these four ionic liquids, ester-functionalized cations can help to improve the tensile strength (2a, 0.943 MPa; 2b, 1.113 MPa) of the cured system, while ether-functionalized cations are more beneficial to improve elongation at break (1a, 522.90%; 1b, 484.45%). Ester-functionalized ionic liquids are more beneficial to reduce the glass transition temperature of HTPB elastomers. The storage modulus of HTPB elastomers containing NO₃^- is higher, while that of HTPB elastomers containing NTf₂^- is lower. The crosslink densities of HTPB/TDI/2a and HTPB/TDI/2b plasticized by ester-functionalized ionic liquids are larger, which are 9369 and 9616 mol/m³, respectively. There are hydrogen bond interactions between the ionic liquid and the HTPB elastomer, and these interactions changed the distribution of the hard and soft segments in the polymer molecules.

A Brief Evaluation of Antioxidants, Antistatics, and Plasticizers Additives from Natural Sources for Polymers Formulation

The circular economy plays an important role in the preparation and recycling of polymers. Research groups in different fields, such as materials science, pharmaceutical and engineering, have focused on building sustainable polymers to minimize the release of toxic products. Recent studies focused on the circular economy have suggested developing new polymeric materials based on renewable and sustainable sources, such as using biomass waste to obtain raw materials to prepare new functional bio-additives. This review presents some of the main characteristics of common polymer additives, such as antioxidants, antistatic agents and plasticizers, and recent research in developing bio-alternatives. Examples of these alternatives include the use of polysaccharides from agro-industrial waste streams that can be used as antioxidants, and chitosan which can be used as an antistatic agent.

Self-Plasticized PVC Prepared by Introducing Fatty Acid to the PVC with Triglycidyl Isocyanurate as an Intermediate Bridge

The phthalate-free self-plasticization of poly(vinyl chloride) (PVC) conforms to the concept of green chemistry. In this work, phthalate-free, biocontaining, self-plasticized PVC with nonmigration (4-an-TG-X-PVC; X = R, P, or O) was prepared by covalent attachment of ricinoleic acid, palmitic acid, and oleic acid, respectively, to the PVC matrix with 4-aminothiophenol and triglycidyl isocyanurate (TGIC) as intermediate bridges. 4-Aminothiophenol and TGIC acted as the nucleophilic reagent and the thermally stable substance, respectively. The 4-an-TG-X-PVC was observed by diverse characterization methods. Specifically, Fourier transform infrared spectra, ¹H nuclear magnetic resonance, gel permeation chromatography, and migration stability tests proved the successful synthesis of 4-an-TG-X-PVC. Compared to the neat PVC, the mechanical property of 4-an-TG-X-PVC is better. The glass transition temperature (T _g) of PVC is 81.24 °C, while that of 4-an-TG-X-PVC decreased to 41.88, 31.49, and 46.91 °C. The 4-an-TG-X-PVC showed higher elongation at break and lower tensile strength than neat PVC. Simultaneously, the thermal property of 4-an-TG-X-PVC got a boost. Thermogravimetry-infrared and thermogravimetry-mass spectrometry showed that 4-an-TG-X-PVC released less HCl than neat PVC in a thermal environment. Discoloration experiments demonstrated that 4-an-TG-P-PVC had better heat stabilization and better color than 4-an-TG-O-PVC and 4-an-TG-R-PVC. This work provides a viable solution to the dependence on phthalates, reduced human health and ecological risks, and endowed PVC with improved thermal stability and nonmigration performance.