Thermal Stability and Non-isothermal Kinetic Analysis of Suspension Poly(vinyl chloride) Films Formulated with Phosphonium-Based Ionic Liquids

Abstract

This work addresses the short-term thermal stability of suspension poly(vinyl chloride) (PVC) films formulated with phosphonium ionic liquids, PhILs (trihexyl(tetradecyl)phosphonium dicyanamide, [ P 1 4 , 6 , 6 , 6 ] [ d c a ] ; t r i h e x y l ( t e t r a d e c y l ) p h o s p h o n i u m b i s -(trifluoromethylsulfonyl)imide, [P 14,6,6,6 ][Tf 2 N]; tetrabutyl phosphonium chloride, [P 4,4,4,4 ][Cl]) and their mixtures with a conventional plasticizer (diisononyl phthalate, DINP). Kinetic parameters for the dehydrochlorination step were determined using a well-accepted isoconversional (multiheating-rate) approach. Results show that PVC films formulated with PhILs, and their mixtures with DINP, present lower thermal stability than those formulated only with DINP, and in spite of PhILs' higher intrinsic thermal stability. Nevertheless, PVC films formulated with [P 14,6,6,6 ][Tf 2 N] present the highest long-term thermal stability. Calculated kinetic parameters provide quite good predictions of the thermally stimulated decomposition of most of the targeted formulations. These results are expected to assist on the identification of potential applications of PhILs in the life cycle assessment of PVC-based materials, either as plasticizers/thermal stabilizers or as catalysts for PVC waste recycling processes.

Insights into the Enhanced Oxidative Thermal Stability of Nanoparticle Organic Hybrid Materials Developed for Carbon Capture and Energy Storage

“…E a for thermal decomposition reactions can be estimated at various extents of conversion, α, which can be obtained by converting the mass fraction of the degrading species. For example, α can be determined at a given temperature ( T ) or reaction time ( t ) by where w i is the initial weight fraction of the sample, w is the weight fraction of the sample at a given time ( t ) or temperature ( T ), and w f is the weight fraction of the sample at the end of the reaction. , The general governing equation for a kinetic process can be represented by where the rate of conversion with respect to time (dα/d t ) depends upon a rate constant, k , and a function, f , which can take one of several forms depending upon the reaction model (an example is given in a later section). − The rate constant, k , depends upon T with an Arrhenius relationship where A is a pre-exponential frequency factor, E a is the apparent activation energy, and R is the ideal gas constant. , Equation and the heat rate, β can be substituted back into eq to give the following expression: which can be further derived or integrated to determine the apparent activation energy for a given material, without the need for knowing the exact form of the decomposition kinetic model, f (α). , …”

Simultaneous Enhancements of Ultraviolet-Shielding Properties and Thermal Stability/Photostability of Poly(vinyl chloride) via Incorporation of Defect-Rich CeO2 Nanoparticles

“…Figure A shows the 3D-FTIR spectra of the gaseous products evolved from the PVC–CeO 2 -4-500 film (2 wt %) under different pyrolysis temperatures. Typically, the pyrolysis process mainly has two stages: the release of HCl and chain fracture process. ,− As shown in Figure A, broad absorption peaks in the 2600–3100 cm –1 region, assigned to the stretching vibration of the H–Cl group, increase first and decrease later in the temperature range of 278–412 °C. Meanwhile, the gradually increased absorption peaks of H 2 O and CO 2 (3500–4000 cm –1 ) and absorption peaks of chlorinated compounds (1520–1950 cm –1 ) confirm the deep pyrolysis and oxidation of PVC during the pyrolysis process. , Notably, characteristic absorption peaks correspond to the gaseous HCl appear at 278 °C, reach the maximum intensity at 306 °C, and disappear at 412 °C, whereas they are 262, 293, and 384 °C for pristine PVC (Figure S6a), respectively, indicating that the addition of 2 wt % CeO 2 -4-500 nanoparticles can put off the initial pyrolysis temperature by 16 °C.…”

“…Poly­(vinyl chloride) (PVC), an indispensable plastic material, is wildly used in industry, agriculture, architecture, household items, and medicine for its virtue of chemical resistance, abrasion resistance, electrical insulator, sound/thermal insulation, and mature production technology. − The global PVC consumption is expected to be 49.5 million tons in 2020 and grows sustainably with a rate of 4.9% per annum . However, because of its intrinsic composition and structural features, PVC suffers from rapid dehydrochlorination reaction and the subsequent HCl-catalytic degradation reaction under heat or ultraviolet (UV) light radiation, as well as the so-generated deterioration of esthetic and mechanical properties. − Therefore, the addition of thermal or UV stabilizers is indispensable for enhancing the stability of PVC materials.…”

Preparation of ZnO nanoparticles modified with silane cross-coupling agent to fabricate anti-UV Poly(vinyl chloride) films

“…For example, it suffers from aging and loss of their mechanical properties and appearances under exposure to UV radiation. Anti-UV polymers 3 material that can protect PVC have received significant attention because of the inevitable harmfulness caused by UV light and the deterioration of mechanical properties of PCV [5,6].…”