A comparative study performance of cationic organic montmorillonite prepared by different methods

2018 ◽  
Vol 25 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Daojin Zhou ◽  
Zepeng Zhang ◽  
Jialun Tang ◽  
Sanqin Wu ◽  
Jiali Zhao
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Comparative Study ◽  
Environment Friendly ◽  
Organic Montmorillonite ◽  
Loop Area ◽  
Structures And Properties ◽  
Swelling Capacity ◽  
Study Performance

AbstractIn this paper, cationic organic montmorillonites (OMts) were prepared by dry, semi-dry, and wet methods. The structures and properties of these OMts according to the modification methods were studied. By the characterization of XRD, TG-DTA, lipophilicity, and thixotropy, the results showed that cationic OMt prepared by wet method with sufficient surfactants had better properties, including contact angle, swelling capacity, thixotropic loop area, and thermal stability compared with cationic OMt prepared by dry and semi-dry methods. Attention should be paid that with low ratio amount of surfactants used, cationic OMt prepared by the semi-dry method had favorable properties compared with cationic OMt prepared by wet method, and it had the potential to be applied in industrial field due to its environment-friendly and modification efficiency characteristics.

scholarly journals Synthesis and Characterization of Biodegradable Polyester/Polyether WPU As The Environmental Protection Coating

2021 ◽  
Author(s):  
Guangfeng Wu ◽  
Xin Song ◽  
ZhiHui Yang ◽  
Ying Chun Li ◽  
HuiXuan Zhang
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Degradation Rate ◽  
Soft Segment ◽  
Buffer Solution ◽  
Water Contact ◽  
Elongation At Break ◽  
Protection Coating

Abstract Polyester diol PCL and PBA, polyether diol PTMG and polycarbonate diol PCDL were used as components of WPU soft segment, respectively. Polyether PTMG-WPU has the worst hydrolytic property and the highest thermal stability. The maximum degradation rate temperature Tmax is 407.8°C, the water contact angle reaches 89.5°. Traditional polyester PCL-WPU shows the strongest hydrolysis performance, the smallest water contact angle, only 71.7°, the water absorption rate of 72 hours at room temperature is as high as 26.7%. However, the thermal stability of PCL-WPU is lower, the soft segment Tg is -52.3°C, and Tmax is only 333.7°C, but the mechanical propertie of which is the best, the tensile strength is 58.3 MPa, and the elongation at break reaches 857.9%. The most important thing is that the structure of polyester PCL-WPU is more easily destroyed by lipase and water molecules. The acidic products produced after hydrolysis will further promote the degradation of polyester. Therefore, compared with other WPUs, PCL -WPU has the best biodegradability and the most obvious degradation effect under the same conditions. The degradation rate of PTMG-WPU after 30 days of degradation in 0.6% lipase PBS buffer solution and soil was only 4.2% and 2.3%, while the highest degradation rate of traditional polyester PCL-WPU reached 41.7% and 32.0%, respectively. In addition, polycarbonate PCDL-WPU has the highest hardness, reaching 95.5 HD. But its other performances are lower than PCl-WPU.

Preparation and Characterization of PET/MMT Nanocomposition Modified by MDI

2014 ◽  
Vol 904 ◽  
pp. 7-9
Author(s):  
Xiao Hua Gu ◽  
Xi Wei Zhang ◽  
Bao Yun Xu ◽  
Peng Zeng
Keyword(s):  
Thermal Stability ◽  
In Situ Polymerization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Organic Montmorillonite ◽  
Polymerization Method ◽  
Thermal Stability Of

In this paper, the diphenyl methane diisocyanate (MDI) was used to modify montmorillonoid (MMT) and got the organic montmorillonite (OMMT), which was used with the monomers of PET by in situ polymerization method to prepare PET/MMT nanocomposition. The OMMT was analyzed by the X ray diffraction (XRD) to test the change of the spacing layer. Dispersion of MMT in the PET/MMT nanocomposites were studied with XRD and SEM and by means of thermogravimetric analyzer (TGA) on the thermal stability of PET/MMT nanocomposites. The results showed that, MDI modified MMT successfully, and the compatibility of MMT and PET was increased .

scholarly journals Characteristics, Compression, and Buffering Performance of Pomelo-Like Hierarchical Capsules Containing Shear Thickening Fluid

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1138 ◽  
Author(s):  
Ting-Ting Li ◽  
Junli Huo ◽  
Xing Liu ◽  
Hongyang Wang ◽  
Bing-Chiuan Shiu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Shear Thickening ◽  
Fickian Diffusion ◽  
Processing Temperature ◽  
Environment Friendly ◽  
Shear Thickening Fluid ◽  
Swelling Capacity ◽  
Swelling Coefficient ◽  
Kinetic Release ◽  
Kinetic Diffusion

In this study, a double-walled and pomelo-like hierarchical shear thickening fluid (STF) is successfully encapsulated using the simple and environment-friendly calcium alginate encapsulation technique by instilling STF into sodium alginate (SA) and crosslinking by calcium chloride solution. The encapsulated STF has a pomelo-like structure with a shell thickness of 2.9 μm and core pores with a size of 21.43 μm. The effect of the size of STF capsules (2.10, 1.89, 1.86, 1.83, 1.73, and 1.63 mm) is explored in terms of thermal stability, swelling capacity, mechanical property, and release performance. The buffering performance of different sizes of STF-containing capsules is also investigated. The pomelo-like STF capsules can withstand a processing temperature of 250 °C. With a decrease in particle size, the compression strain energy slowly increases first and then rapidly enhances. The kinetic release of pomelo-like STF capsules conforms to Fickian diffusion. STF-containing capsules with a diameter of 1.83 mm present the greatest thermal stability, the highest STF amount, the maximum swelling coefficient, and the fastest kinetic diffusion. STF-containing capsules also have an improved buffering performance in PU foam. This capsule has the best comprehensive performance and can adapt to diversified applications, such as personnel armor and other protective sports equipment.

Preparation and Characterization of PVA-MSA/mCS Bipolar Membrane

2013 ◽  
Vol 634-638 ◽  
pp. 2336-2341
Author(s):  
Hong Fang Xie ◽  
Yan Chun Xiao ◽  
Mei Zhen Zhou ◽  
Shuang Chen ◽  
Zhen Chen
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Contact Angle ◽  
Nano Materials ◽  
Bipolar Membrane ◽  
Nano Tio2 ◽  
Nano Zno ◽  
Cation Layer ◽  
Nano Fe3o4

Polyvinyl Alcohol (PVA) was blent with sodium alginate (SA) and chitosan (CS) respectively in order to enhance flexibility and compatibility of bipolar membrane(BPM). The PVA-mSA/mCS BPM was prepared by a paste method. The PVA/ SA and the PVA / CS was cross-linked by inorganic nano-materials and glutaraldehyde(GA), respectively. The SEM photographs showed the PVA-ZnO-SA/mCS BPM was consists of anion layer and cation layer. The thickness of the BPM was 121μm, the interface of BPM was 5μm. The Electronic spectrum (EDS) indicated that ZnO well-distributed in cation layer. The J-V curve and the AC impedances of PVA-ZnO-SA/mCS BPM showed lower working voltage and smaller membrane impedance. The contact Angle of PVA-ZnO-SA/mCS dropped down from the original 101.01° to 32.65°. Compared of TG curves of the BPMs modified by nano-Fe3O4, nano-TiO2 and nano-ZnO, the surface of the PVA-ZnO-SA/mCS BPM exhibited stronger hydrophilic. The dopping nano-ZnO improved the hydrophilic property, thermal stability and mechanical properties of the PVA-ZnO-SA/mCS.

scholarly journals The Preparation and Characterization of Chitosan-Based Hydrogels Cross-Linked by Glyoxal

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2449
Author(s):  
Beata Kaczmarek-Szczepańska ◽  
Olha Mazur ◽  
Marta Michalska-Sionkowska ◽  
Krzysztof Łukowicz ◽  
Anna Maria Osyczka
Keyword(s):  
Thermal Stability ◽  
Tannic Acid ◽  
Dental Pulp ◽  
Blood Compatibility ◽  
Dental Pulp Cells ◽  
Preliminary Assessment ◽  
Human Dental Pulp Cells ◽  
Human Dental Pulp ◽  
Pulp Cells

In this study, hydrogels based on chitosan cross-linked by glyoxal have been investigated for potential medical applications. Hydrogels were loaded with tannic acid at different concentrations. The thermal stability and the polyphenol-releasing rate were determined. For a preliminary assessment of the clinical usefulness of the hydrogels, they were examined for blood compatibility and in the culture of human dental pulp cells (hDPC). The results showed that after immersion in a polyphenol solution, chitosan/glyoxal hydrogels remain nonhemolytic for erythrocytes, and we also did not observe the cytotoxic effect of hydrogels immersed in tannic acid (TA) solutions with different concentration. Tannic acid was successfully released from hydrogels, and its addition improved material thermal stability. Thus, the current findings open the possibility to consider such hydrogels in clinics.

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