scholarly journals Effects of preparation methods of mixed calcium and zinc thermal stabilizers derived from dimer fatty acid and tung-oil based C22 triacid on properties of PVC

2017 ◽  
Vol 19 (2) ◽  
pp. 78-87 ◽  
Author(s):  
Mei Li ◽  
Mei Wang ◽  
Shouhai Li ◽  
Kun Huang ◽  
Wei Mao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Dynamic Mechanical Properties ◽  
Calcium Soap ◽  
Preparation Methods ◽  
Rheological Analysis ◽  
Thermal Stabilizer ◽  
Zinc Salts ◽  
Dimer Fatty Acids ◽  
Synthetic Routes ◽  
Congo Red Test

Abstract Calcium and zinc salts of dimer fatty acids (DFA-Ca and DFA-Zn) were synthesized using direct neutralization and metathesis technologies, respectively. The adduct of maleic anhydride and methyl eleostearate (MAME) was also converted to the corresponding zinc soap (C22TA-Zn) and calcium soap (C22TA-Ca) by the two different synthetic routes. Mixed Ca/Zn salts between DFA-Ca and DFA-Zn, and between C22TA-Zn and C22TA-Ca were used as thermal stabilizers for poly(vinyl chloride) (PVC). The PVC thermal stability was determined using Congo red test, discoloration test, torque rheological analysis and TGA. Dynamic mechanical properties were also tested. Results indicated that the DFA-Ca/DFA-Zn thermal stabilizer from direct neutralization technology was found to be superior to that of the metathesis product. The C22TA-Ca/C22TA-Zn thermal stabilizer from direct neutralization method had overall superior thermal stability, and displayed modulus and glass transition comparable to that of metathesis product. Direct neutralization method was more excellent and convenient than metathesis technology.

Influence of Polyols as a Co-Stabilizer on Stabilization Efficiency of Calcium/Zinc Stabilizers to PVC/ACS Blend

2012 ◽  
Vol 549 ◽  
pp. 453-456
Author(s):  
Jun Gang Gao ◽  
Jiang Bo Yang ◽  
Xiao Qian Liu ◽  
Feng Li Zhu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Congo Red ◽  
Dynamic Mechanical Properties ◽  
Synergy Effect ◽  
Dynamic Mechanical Analyzer ◽  
Melt Viscosity ◽  
Rotational Rheometer ◽  
Dynamic Mechanical ◽  
Thermal Stabilizer

In order to prepare good thermal stabilizer for PVC/ACS blends, the Congo red methods was adopted to determine the thermal stabilizing time of blends and study the synergy effect between polyols and Ca/Zn stabilizer for PVC/ACS blends. The rheological behaviors and dynamic mechanical properties of PVC/ACS blends were investigated by rotational rheometer and dynamic mechanical analyzer (DMA). The results showed that the different polyols have different influences on the thermal stability, melt viscosity, dynamic mechanical properties of PVC/ACS blends. The pentaerythritol has a good synergy effect with Ca/Zn stability and the PVC/ACS blend has a lower melt viscosity.

Synthesis and properties of phthalonitrile-based resins containing spirocycle acetal

2020 ◽  
pp. 095400832097759
Author(s):  
Ke Li ◽  
Hua Yin ◽  
Kun Yang ◽  
Pei Dai ◽  
Ling Han ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Room Temperature ◽  
Laser Desorption Ionization ◽  
Scanning Calorimetry ◽  
Rheological Analysis ◽  
Ionization Time ◽  
Dynamic Mechanical ◽  
Nmr Spectrometry ◽  
Current Context

Designing novel low-melting, high-rigidity phthalonitrile resin is of great significance in the current context of development. In this study, rigid spirocycle acetal structure was introduced into phthalonitrile to reduce the melting point and maintain their thermal stability. The chemical structure of resins was confirmed by nuclear magnetic resonance (NMR) spectrometry, matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and Fourier-transform infrared (FTIR) spectroscopy. The curing behaviors were studied by differential scanning calorimetry (DSC). Thermal stability and mechanical properties of the cured resins were investigated by dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The processability was studied by rheological analysis. The results indicated the three monomers had a low melting temperature, wide processing windows and low viscosities. These polymers did not exhibit Tg from room temperature to 400°C, exhibited superb dynamic mechanical property and thermal stability.

scholarly journals Facile synthesis of exfoliated vermiculite nanosheets as a thermal stabilizer in polyvinyl chloride resin

RSC Advances ◽  
2019 ◽  
Vol 9 (34) ◽  
pp. 19675-19679
Author(s):  
Weiliang Tian ◽  
Zhong Li ◽  
Kewei Zhang ◽  
Zhenhong Ge
Keyword(s):  
Thermal Stability ◽  
Hydrogen Chloride ◽  
Anion Exchange ◽  
Polyvinyl Chloride ◽  
Facile Synthesis ◽  
Excellent Thermal Stability ◽  
Thermal Stabilizer

Well-defined vermiculite nanosheets are exfoliated by a facile water-assisted anion-exchange approach. As its negatively charged laminates can stabilize hydrogen chloride, the VMT nanosheets show excellent thermal stability for PVC resin.

Advances in preparation, modification, and application of polypropylene membrane

2016 ◽  
Vol 36 (4) ◽  
pp. 329-362 ◽  
Author(s):  
Nurul F. Himma ◽  
Sofiatun Anisah ◽  
Nicholaus Prasetya ◽  
I Gede Wenten
Keyword(s):  
Thermal Stability ◽  
High Performance ◽  
Chemical Resistance ◽  
Low Cost ◽  
Comprehensive Overview ◽  
Preparation Methods ◽  
Good Thermal Stability ◽  
Polypropylene Membrane ◽  
Membrane Fabrication ◽  
Potential Applications

Abstract Polypropylene (PP) is one of the most used polymers for microporous membrane fabrication due to its good thermal stability, chemical resistance, mechanical strength, and low cost. There have been numerous studies reporting the developments and applications of PP membranes. However, PP membrane with high performance is still a challenge. Thus, this article presents a comprehensive overview of the advances in the preparation, modification and application of PP membrane. The preparation methods of PP membrane are firstly reviewed, followed by the modification approaches of PP membrane. The modifications includes hydrophilic and superhydrophobic modification so that the PP membranes become more suitable to be applied either in aqueous applications or in non-aqueous ones. The fouling resistant of hydrophilized PP membrane and the wetting resistant of superhydrophobized PP membrane are then reviewed. Finally, special attention is given to the various potential applications and industrial outlook of the PP membranes.

One-pot synthesis of PMMA/montmorillonite nanocomposites

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Adam Kiersnowski ◽  
Maria Trelinska-Wlazlak ◽  
Justyna Dolega ◽  
Jacek Piglowski
Keyword(s):  
Single Step ◽  
Layered Silicates ◽  
Trimethylammonium Chloride ◽  
One Pot ◽  
Structural Investigations ◽  
Preparation Methods ◽  
Simple Preparation ◽  
Acrylic Copolymers ◽  
Synthetic Routes ◽  
Montmorillonite Nanocomposites

AbstractThis article describes simple preparation methods of poly(methyl methacrylate) (PMMA)/synthetic montmorillonite nanocomposites by single-step insitu polymerizations. Compatibility between PMMA and the silicate was ensured by an addition of (3-acrylamidepropyl) trimethylammonium chloride (AAPTMA). The work also compares how different synthetic routes, namely emulsion and solution polymerization, affect the structure as well as thermal and mechanical properties of obtained nanocomposites. The results of structural investigations clearly show, that both the techniques lead to intercalated nanocomposites, but emulsion polymerization allows more effective deflocculating and intercalating of the clay with acrylic copolymers. The addition of small amounts of layered silicates causes an increase in thermal stability and stiffness of the materials. It is demonstrated that at 5 wt. % of the filler, the temperature of 10 % weight loss was shifted up by nearly 50 K in comparison to the neat PMMA. In the same sample, the Young’s modulus of the material was found to be increased by 26 %.

Pt/UiO-66 Nanocomposites as Catalysts for CO2 Methanation Process

2019 ◽  
Vol 19 (6) ◽  
pp. 3187-3196 ◽  
Author(s):  
Maria Mihet ◽  
Gabriela Blanita ◽  
Monica Dan ◽  
Lucian Barbu-Tudoran ◽  
Mihaela D Lazar
Keyword(s):  
Thermal Stability ◽  
Surface Area ◽  
Metal Organic Framework ◽  
Catalytic Performance ◽  
Molar Ratio ◽  
High Dispersion ◽  
Co2 Methanation ◽  
Preparation Methods ◽  
Good Thermal Stability ◽  
Catalytic Support

Pt/UiO-66 nanocomposites with platinum target concentration of 3 wt.% were prepared by 3 preparation methods, characterized and tested in the CO2 methanation process. Choice of the microporous UiO-66 metal-organic framework (Zr6O4(OH)4 with 1,4-benzene-dicarboxylate ligand) as catalytic support was motivated by the CO2 chemisorption capacity (proven by CO2-TPD profiles), large specific surface area (1477 m2/g) which favors a high dispersion of metal nanoparticles and good thermal stability. The preparation methods for the Pt/UiO-66 nanocomposites are: (1) wetimpregnation followed by reduction in H2 at 200 °C for 2 h; (2) wet-impregnation followed by reduction with an aqueous solution of NaBH4; and (3) “double-solvent” method, followed by reduction with NaBH4. The UiO-66 based nanocomposites were characterized by N2 adsorption–desorption (BET method), XRD, and SEM/TEM. The Pt/UiO-66 catalyst prepared by method 3 was chosen for catalytic testing due to its highest surface area, smallest platinum nanoparticles (PtNPs) size, the localization of PtNPs both on the grain’s internal and external surface and best thermal stability in the desired temperature range. Its capacity to adsorb and activate CO2 and H2 was evaluated in thermo-programmed desorption experiments (H2-TPD and CO2-TPD). Hydrogen is molecularly adsorbed, while CO2 is adsorbed both molecularly and dissociatively. The catalytic performance in the CO2 methanation process was evaluated by Temperature Programmed Reactions (TPRea, 2 °C/min, 30–350 °C), at atmospheric pressure. The best results were obtained at 350 °C, CO2:H2 molar ratio of 1:5.2 and GHSV ═ 1650 h−1. In these conditions CO2 conversion is almost 50% and CH4 selectivity is 36%, the rest of the converted CO2 being transformed in CO.

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