Design and Synthesis of a New Mannitol Stearate Ester-Based Aluminum Alkoxide as a Novel Tri-Functional Additive for Poly(Vinyl Chloride) and Its Synergistic Effect with Zinc Stearate

Abstract

Thermal stabilizers, lubricant, and plasticizers are three crucial additives for processing poly(vinyl chloride) (PVC). In this study, a new mannitol stearate ester-based aluminum alkoxide (MSE-Al) was designed and synthesized as a novel additive for PVC. The thermal stability and processing performance of PVC stabilized by MSE-Al were evaluated by the Congo red test, conductivity measurement, thermal aging test, ultravioletevisible (UV–Vis) spectroscopy test, and torque rheometer test. Results showed that the addition of MSE-Al could not only markedly improve the long-term thermal stability of PVC, but also greatly accelerate the plasticizing and decrease the balance torque, which demonstrated that MSE-Al possessed a lubricating property. Thus, MSE-Al was demonstrated to be able to provide tri-functional additive roles, e.g., thermal stabilizer, plasticizer, and lubricant. The test results for the thermal stability of PVC indicated that the initial whiteness of PVC stabilized by MSE-Al was not good enough, thus the synergistic effect of MSE-Al with zinc stearates (ZnSt2) on the thermal stability of PVC was also investigated. The results showed that there is an appreciable synergistic effect between MSE-Al and ZnSt2. The thermal stabilization mechanism and synergism effect of MSE-Al with ZnSt2 are then discussed.

A novel evaluation method for dehydrochlorination of plasticized Poly(vinyl chloride) containing heavy metal‐free thermal stabilizing synergistic agent

“…And the curve slope is very sharp (high inclination). While for the results obtained in the standard method shown in Figure 6, which depends on measuring the conductivity, we note that the induction time and stability time were short, and their values ranged between 0.45 and 0.59 hour, respectively, which means that the thermal stability of PVC is significantly reduced at high temperatures 20,21 …”

Effect of silane treated fly ash on physico‐mechanical, morphological, and thermal properties of recycled poly(vinyl chloride) composites

“…It is interesting to note that, torque stabilization in case of r‐PVC shows 2.16 Nm at 5 min, whereas in case of the treated composite samples, it decreased to negative value. This phenomenon is attributed to the addition of FA (Si) and ESO during melt blending which under lubricating effect and uniformly distributes within the recycled polymer matrix 30,31 …”

Thermal Stability of Nanosilica-Modified Poly(vinyl chloride)

“…[2,3,[9][10][11][12][13][14]. The stabilizing effect of the new types of compounds with a capacity to improve the thermal stability of PVC, such as zinc urate, unsaturated maleic acid-sorbitol ester, and zinc maleic acid-sorbitol ester complex, as well as mannitol stearate ester-based aluminum alkoxide was also reported [15][16][17]. This effect is often synergistic with commercially used thermal stabilizers [15,16] and other additives used in PVC blends, such as cross-linking agents and antioxidants [18].…”

“…The Congo red test [ 16 , 17 , 23 , 36 ] and thermal gravimetric analysis [ 14 , 17 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] were used to determine the thermal stability of PVC in static conditions. The use of Brabender or Haake torque rheometers allows to measure the thermal stability in dynamic conditions [ 16 , 17 , 25 , 37 , 38 ].…”