Evaluation of the Thermal Stabilization Effect of Maleic Anhydride Derivatives on Polyvinyl Chloride

2012 ◽  
Vol 535-537 ◽  
pp. 1167-1170
Author(s):  
Jian Ping Liu ◽  
Xia Song ◽  
Wei Yuan ◽  
Xiao Yan Wang

Here, we synthesized a series of polymeric thermal stabilizers for polyvinyl chloride (PVC) based on maleic anhydride derivatives, including N-phenylmaleimide (NPMI), N-p-chlorophenyl maleimide (NCIPMI), N-p-nitrophenyl maleimide (NNOPMI), dibutyltin maleate (DBTM) and dioctyltin maleate (DOTM). Five specimens were prepared by mixing and rolling through a blending machine and a double-roller mixer, respectively. These samples were first subjected to thermal degradation in a 180°C hot oven, and fractions were collected every 10 min, followed by spotting on a slip of test paper. From the degree of color change in the test paper, the influences of these compounds on the thermal stability of PVC were estimated and such mechanisms were also discussed.

2012 ◽  
Vol 581-582 ◽  
pp. 81-84
Author(s):  
Jian Ping Liu ◽  
Hong Zhou Shang ◽  
Xia Song ◽  
Wei Yuan ◽  
Shu Mei Zhou

Bis (mercaptoethanol oleate) dimethyl tin was synthesized and added to polyvinyl chloride (PVC) with various ratios. Specimens were prepared by mixing and rolling through a double-roller mixer, and their static thermal stabilities were estimated by the oven static thermal aging experiments. The influence of the bis (mercaptoethanol oleate) dimethyl tin on the dynamic thermal stability of PVC was tested through a haack torque rheometer (HAAKE PolyLab QC). The tensile strength and rate of elongation at break of the PVC specimens were evaluated by a servo-controlled tensile testing machine. The results show that the bis (mercaptoethanol oleate) dimethyl tin has excellent static and dynamic thermal stabilization effect on PVC, and to some extent, can improve the breaking elongation rate the PVC sample.


2013 ◽  
Vol 820 ◽  
pp. 84-87
Author(s):  
Zheng Zhou Wang ◽  
Charles A. Wilkie

Cadmin sulfate nanoparticles, hollow sphere (CdS-HS) and rode (CdS-NR) were synthesized by ultrasonic and solvothermal process, respectively. The effect of the two kinds of nanoparticles on flammability of polystyrene was investigated using cone calorimeter (Cone) and microscale combustion calorimeter (MCC). Cone data indicate that the incorporation of 1% CdS nanoparticles leads to a about 20% reduction in the peak heat release rate (PHRR) compared to the pure PS; CdS-NR is more efficient in reducing the PHRR proved by both Cone and MCC results. The TG results show that the addition of the nanoparticles mainly increases thermal stability of PS at high temepratures.


Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1105 ◽  
Author(s):  
Palin ◽  
Rombolà ◽  
Milanesio ◽  
Boccaleri

Plasticized–Poly(vinyl chloride) (P-PVC) for cables and insulation requires performances related to outdoor, indoor and submarine contexts and reduction of noxious release of HCl-containing fumes in case of thermal degradation or fire. Introducing suitable nanomaterials in polymer-based nanocomposites can be an answer to this clue. In this work, an industry-compliant cable-grade P-PVC formulation was added with nanostructured materials belonging to the family of Polyhedral Oligomeric Silsesquioxane (POSS). The effects of the nanomaterials, alone and in synergy with HCl scavenging agents as zeolites and hydrotalcites, on the thermal stability and HCl evolution of P-PVC were deeply investigated by thermogravimetric analysis and reference ASTM methods. Moreover, hardness and mechanical properties were studied in order to highlight the effects of these additives in the perspective of final industrial uses. The data demonstrated relevant improvements in the thermal stability of the samples added with nanomaterials, already with concentrations of POSS down to 0.31 phr and interesting additive effects of POSS with zeolites and hydrotalcites for HCl release reduction without losing mechanical performances.


2008 ◽  
Vol 389 (9) ◽  
Author(s):  
Hester G. O'Neill ◽  
Pierre Redelinghuys ◽  
Sylva L.U. Schwager ◽  
Edward D. Sturrock

Abstract The N and C domains of somatic angiotensin-converting enzyme (sACE) differ in terms of their substrate specificity, inhibitor profiling, chloride dependency and thermal stability. The C domain is thermally less stable than sACE or the N domain. Since both domains are heavily glycosylated, the effect of glycosylation on their thermal stability was investigated by assessing their catalytic and physicochemical properties. Testis ACE (tACE) expressed in mammalian cells, mammalian cells in the presence of a glucosidase inhibitor and insect cells yielded proteins with altered catalytic and physicochemical properties, indicating that the more complex glycans confer greater thermal stabilization. Furthermore, a decrease in tACE and N-domain N-glycans using site-directed mutagenesis decreased their thermal stability, suggesting that certain N-glycans have an important effect on the protein's thermodynamic properties. Evaluation of the thermal stability of sACE domain swopover and domain duplication mutants, together with sACE expressed in insect cells, showed that the C domain contained in sACE is less dependent on glycosylation for thermal stabilization than a single C domain, indicating that stabilizing interactions between the two domains contribute to the thermal stability of sACE and are decreased in a C-domain-duplicating mutant.


2012 ◽  
Vol 476-478 ◽  
pp. 730-733
Author(s):  
Zhi Dan Lin ◽  
Zi Xian Guan ◽  
Neng Sheng Liu ◽  
Zheng Jun Li

The composites of polypropylene (PP) and wasted PET fabric (WF) were prepared by extrusion blending and injection molding, and then, the interface of the composites was modified by two different types of compatibilizers, i.e., maleic anhydride grafted PP (PP-g-MA) and the mixture of methyl methacrylate (MMA) and styrene (St). The mechanical properties, morphology and thermal stability of these composites were studied.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 228 ◽  
Author(s):  
Ekaterina S. Dolinina ◽  
Elizaveta Yu. Akimsheva ◽  
Elena V. Parfenyuk

Powerful antioxidant α-lipoic acid (LA) is easily degraded under light and heating. This creates difficulties in its manufacture, storage and reduces efficiency and safety of the drug. The purpose of this work was to synthesize novel silica-based composites of LA and evaluate their ability to increase photo and thermal stability of the drug. It was assumed that the drug stabilization can be achieved due to LA-silica interactions. Therefore, the composites of LA with unmodified and organomodified silica matrixes were synthesized by sol-gel method at the synthesis pH below or above the pKa of the drug. The effects of silica matrix modification and the synthesis pH on the LA-silica interactions and kinetics of photo and thermal degradation of LA in the composites were studied. The nature of the interactions was revealed by FTIR spectroscopy. It was found that the rate of thermal degradation of the drug in the composites was significantly lower compared to free LA and mainly determined by the LA-silica interactions. However, photodegradation of LA in the composites under UV irradiation was either close to that for free drug or significantly more rapid. It was shown that kinetics of photodegradation was independent of the interactions and likely determined by physical properties of surface of the composite particles (porosity and reflectivity). The most promising composites for further development of novel silica-based formulations were identified.


Author(s):  
Lijie Qu ◽  
Zhenyu Wang ◽  
Jing Qian ◽  
Zhengbin He ◽  
Songlin Yi

Abstract Acidic aluminum sulfate hydrolysis solutions can be used to catalyze the thermal degradation of wood in a mild temperature environment, and thus reduce the temperature required for heat treatment process. To improve the dimensional and thermal stability of Chinese fir during heat treatment at 120 °C, 140 °C and 160 °C, this study investigated the effects of soaking pretreatment with 5%, 10% and 15% aluminum sulfate on the chemical and structural changes of the heat-treated Chinese fir. The results indicated that the samples treated at 15% aluminum sulfate concentration and 160 °C heat treatment achieved the best dimensional and thermal stability. Chemical analyses by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) indicated that the catalysis of aluminum sulfate resulted in degradation of hemicelluloses during the heat treatment, and an increase in the soaking concentration and heat treatment temperature also affected the thermal degradation of celluloses. The scanning electron microscope (SEM) and mass changes test results proved that the hydrolyzed aluminum flocs mainly adhered to the inner wall of the wood tracheid as spherical precipitates, and when the soaking concentration reached 10% and 15%, a uniform soaking effect could be achieved. The thermogravimetric (TG) analysis revealed the soaking pretreatment effectively improved the thermal stability of the heat-treated wood by physically wrapping and promoting the formation of a carbon layer on the wood surface during heat treatment. Thus, aluminum sulfate soaking pretreatment exerted a great effect on the dimensional and thermal stability of wood, allowing heat treatment to be performed at a lower temperature.


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