Investigation of basic zinc cyanurate as a novel thermal stabilizer for poly(vinyl chloride) and its synergistic effect with calcium stearate

The Facile Strategy of Improving the Long-Term Stability of Highly Transparent Polyvinyl Chloride by Introducing Unsaturated Zn Oleate and Uracil Derivatives

In order to improve the initial color and the long-term heat stability of super-transparent polyvinyl chloride (PVC), a series of composite heat stabilizers consisting of unsaturated Zn oleate and uracil derivatives have been designed in this paper. The uracil derivatives are 1,3-dimethyl-6-amino-uracil (DAU) and 6,6′-diamino-1,1′,3,3′-tetramethyl-5,5′-(ethylidene)bisuracil (OSU). The static thermal stability, dynamic thermal stability, and transparency were used to evaluate the properties of the stabilized transparent PVC sheets. The results indicate that the compatibility between the stabilizer and PVC was greatly enhanced by introducing an unsaturated long-chain Zn oleate and a long alkyl chain bisuracil derivative. Through the thermal discoloration test, the best ratio of DAU/zinc oleate (DAU/Zn) and OSU/zinc oleate (OSU/Zn) was determined to be 4:1, with a total amount of 3 phr in 100 phr PVC. It was verified that the combination of zinc oleate with uracil derivatives could improve the long-term thermal stability of PVC, and the DAU/Zn was better than that of the OSU/Zn. In addition, through the transmission/haze verification, adding a proper amount of epoxidized soybean oil (ESBO) and phosphite ester to the OSU/Zn system has a certain synergistic effect. The thermal stability and transparency of PVC can be remarkably enhanced.

The thermal stabilization behavior and mechanism of metal organic framework with high thermal stability towards PVC

Thermal stabilizer plays a crucial role in improving the thermal stability of PVC samples. However, the effect of thermal behavior of stabilizer itself on PVC sample has been rarely reported....

Preparation of Magnesium-Aluminum Hydrotalcite by Mechanochemical Method and Its Application as Heat Stabilizer in poly(vinyl chloride)

The traditional methods for preparing magnesium aluminum layered double hydrotalcite (Mg₂Al-CO₃LDHs) in industry include coprecipitation and hydrothermal methods. Both these methods have the disadvantages of high preparation cost and complicated water washing process. Using Mg(OH)₂, Al(OH)₃, and CO₂ as raw materials in this work, the Mg₂Al-CO₃ LDHs are successfully prepared by mechanochemical method, which solves the shortcomings of traditional preparation method and realizes the conversion and utilization of CO₂ resource. The prepared Mg₂Al-CO₃ LDHs are evaluated as a heat stabilizer in poly(vinyl chloride) (PVC). The result indicates that, when 2.4 phr Mg₂Al-CO₃ LDHs, 0.3 phr ZnSt₂, and 0.3 phr of zinc acetylacetonate are added to the PVC, the thermal stability time of PVC can reach 190 min, which is better than PVC containing commercial Mg₂Al-CO₃ LDHs. Meanwhile, its processing performance is basically the same as the PVC containing commercial Mg₂Al-CO₃ LDHs.

Development and Investigation of Lanthanum Sulfadiazine with Calcium Stearate and Epoxidised Soyabean Oil as Complex Thermal Stabilizers for Stabilizing Poly(vinyl chloride)

Lanthanum sulfadiazine (LaSD) was synthesized from sulfadiazine and lanthanum nitrate using water as solvent under alkaline conditions, and was used as a novel rare earth thermal stabilizer to stabilize poly(vinyl chloride) (PVC). The structure of LaSD was characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR) and thermo- gravimetric analysis (TGA). The influence of lanthanum sulfadiazine with calcium stearate (CaSt₂) and epoxidized soybean oil (ESBO) on stabilizing PVC was studied by using the Congo red test, oven discoloration test, UV-vis spectroscopy and thermal decomposition kinetics. The results showed that the addition of LaSD as a thermal stabilizer can significantly improve the initial whiteness and long-term stability of PVC. In addition, the synergies between LaSD, ESBO, and CaSt₂ can provide outstanding improvement in the long-term thermal stability of PVC. When the ratio of LaSD/ESBO/CaSt₂ is 1.8/0.6/0.6, its thermal stability time is 2193 s which is the best state for stabilizing PVC. Furthermore, comparing the reaction energy (E_a) and the variations in the conjugate double bond concentration in PVC samples, the order of thermal stability of PVC was PVC/LaSD/ESBO/CaSt₂ > PVC/LaSD/ESBO > PVC/LaSD. The thermal stability mechanism of LaSD on PVC was studied by the AgCl precipitation method and FTIR spectrum. The results showed that the action of LaSD on PVC was achieved through replacing unstable chlorine atoms and absorbing hydrogen chloride.

Synthesis and Study of Zinc Orotate and Its Synergistic Effect with Commercial Stabilizers for Stabilizing Poly(Vinyl Chloride)

Zinc orotate (ZnOr₂), which is a new kind of poly(vinyl chloride) (PVC) stabilizer, is prepared in this work through the precipitation method, and its impact on the thermal stability of PVC is measured by thermogravimetric analysis (TG), Congo red test, and discoloration test. The results exhibit that the thermal stability of PVC is positively enhanced after the addition of ZnOr₂. In contrast with a commercial thermal stabilizer, zinc stearate (ZnSt₂), a noteworthy improvement was observed that ZnOr₂ could postpone the "zinc burning" of PVC. This is principally ascribed to the Or anion in the structure of ZnOr₂ being able to absorb the HCl released by PVC, and to supersede unstable chlorine atoms in the structure of PVC. In addition, blending ZnOr₂ with calcium stearate (CaSt₂) in diverse mass ratios can significantly accelerate the thermal stability of PVC. Optimum performance was achieved with a CaSt₂:ZnOr₂ ratio of 1.8:1.2. Moreover, an outstanding synergistic effect can be observed when CaSt₂/ZnOr₂ is coupled with other commercial auxiliary stabilizers. The initial color and long-term stability of PVC including CaSt₂/ZnOr₂ is significantly increased when pentaerythritol (PER) is added, while dibenzoylmethane (DBM) can only improve its long-term thermal stability.

Zigzag-Shaped Silver Nanoplates: Synthesis via Ostwald Ripening and Their Application in Highly Sensitive Strain Sensors

Zigzag-shaped Ag nanoplates display unique anisotropic planar structures with unusual jagged edges and relatively large lateral dimensions. These characteristics make such nanoplates promising candidates for metal inks in printed electronics, which can be used for realizing stretchable electrodes. In the current work, we used a one-pot coordination-based synthetic strategy to synthesize zigzag-shaped Ag nanoplates. In the synthetic procedure, cyanuric acid was used both as a ligand of the Ag⁺ ion, hence producing complex structures and controlling the kinetics of the reduction of the cation, and as a capping agent that promoted the lateral growth of the Ag nanoplates. Hence, cyanuric acid played a crucial role in the formation of zigzag-shaped nanoplates. In contrast to previous studies that reported oriented attachment to be the predominant mechanism responsible for the growth of zigzag-shaped nanoplates, Ostwald ripening was the dominant growth mechanism in the current work. Our findings on the particle morphology and crystalline structure of the Ag nanoplates motivated us to use them as conductive materials for stretchable strain sensors. Strain sensors based on nanocomposites of our zigzag-shaped Ag nanoplate and polydimethylsiloxane in the form of a sandwich structure were successfully produced by following a simple, low-cost, and solution-processable method. The strain sensors exhibited extremely high sensitivity (gauge factor ≈ 2000), high stretchability with a linear response (≈27%), and high reliability, all of which allowed the sensor to monitor diverse human motions, including joint movement and phonation.

Plasticization and thermal behavior of hydroxyl and nitrogen rich group-containing tung-oil-based ester plasticizers for PVC

Multifunctional tung-oil-based ester plasticizers were successfully synthesized. These plasticizers exhibit superior plasticization and thermal stability for PVC.

The influence of processing aids on the melt stability and mobility of poly(arylene sulfide sulfone)

The phosphorous antioxidant bis[2,4-bis(1-methyl-1-phenylethyl)phenyl] pentaerythritol diphosphite (s-9228), hindered phenol antioxidant N, N′-hexane-1,6-diylbis-[3,5-di-tert-butyl-4-hydroxyphenylpropionamide] (1098), and zinc acetate (ZnAc) were chosen as processing aids to improve the melt stability and mobility of poly(arylene sulfide sulfone) (PASS). Different contents and components of the processing aids were discussed. The capillary rheometer test demonstrated that 3 wt% ZnAc showed better effect with the change of the shear rates. In contrast, the parallel-plate rheometer test proved that the complex antioxidant, including 0.8 wt% s-9228 and 1.6 wt% 1098, showed better effect with the change of temperature. Both the capillary rheometer and parallel-plate rheometer test showed that the compounding aid consisting of 0.8 wt% s-9228, 1.6 wt% 1098, and 3 wt% ZnAc showed the best effect with the dramatically improved melt stability and mobility. Also, PASS could be processed successfully by extruding and through an injection machine with the help of the compounding aid. Meanwhile, the effects of the applied processing aids on melt complex viscosity and modulus were also discussed.

Mixed calcium and zinc salts of N-(3-amino-benzoic acid)terpene-maleamic acid: preparation and its application as novel thermal stabilizer for poly(vinyl chloride)

N-(3-Amino-benzoic acid)terpene-maleamic acid was successfully prepared, and converted to the corresponding good efficient Ca/Zn-based thermal stabilizers for poly(vinyl chloride).

Highly efficient and antibacterial zinc norfloxacin thermal stabilizer for poly(vinyl chloride)

A novel, highly efficient, antibacterial multifunctional thermal stabilizer, zinc norfloxacin (ZnNo₂) for PVC was prepared, and studied by Congo red test, discoloration, dehydrochlorination test, visible spectroscopy and inhibition zone test.