Effect of manufacture conditions on reverse osmosis desalination performance of polyamide thin film composite membrane and their spiral wound element

The selective laser sintering (SLS) is one of the most important 3D‐printing technologies. However, the challenges in SLS could be in the limited high material cost and single material performance. Development of high‐performance and multifunctional copowders suitable for SLS is of great importance. Here, polyamide 12 (PA12)/boron nitride (BN) thermal conductive copowders suitable for SLS were successfully prepared through solid state shear milling (S3M) technology in combination with cryogenic pulverization technology. The particle size, morphology, grafting reaction between PA12 and BN, rheology behavior, and coalescence behavior of the obtained PA12/BN copowders were carefully investigated. The optimal amount of silica flow additive (0.5 wt %) was determined to achieve the good powder flowability. Under the optimum 3D‐printing conditions, the fabrication of parts with high BN loading could be achieved. When BN content was at 40 wt %, the flexural strength could reach 10.6 MPa and the thermal conductivity could reach 0.55 W/m·k, 77% higher than that of pure PA12. After treated with phenolic epoxy resin, the tensile strength and flexural strength of the printed parts with 40 wt % BN loading could reach 14.2 and 25.6 MPa, which were 130 and 115% higher than those of the untreated 3D‐printed parts, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48766.

Section: Resultsmentioning

confidence: 99%

Solid‐state shear milling method to prepare PA12/boron nitride thermal conductive composite powders and their selective laser sintering 3D‐printing

Yang

Wang

Chen

2019

“…The hydrophobic methyl groups are arranged outward to form a surface layer of hydrocarbon groups, preventing water molecules from coming in contact with the epoxy resin, as shown in Figure 10. The reduction of the surface pores of the modified epoxy resin also helps to reduce water retention 36–38 . Therefore, the water absorption rate of the HTPDMS‐modified epoxy resin is reduced.…”

Section: Resultsmentioning

confidence: 99%

Improving the insulating performance of epoxy resin in humid environments byHTPDMSmodification

Gong

Zhao

Zhang

et al. 2021

The rapid development of the electronic packaging industry imposes stringent requirements on epoxy resin insulation materials for lower water absorption and higher insulation properties. Here, hydroxy‐terminated polydimethylsiloxane (HTPDMS) was grafted on the molecular chain of the epoxy resin for enhanced waterproof and insulating properties of the epoxy resin. The HTPDMS‐modified epoxy resin specimens were prepared and subjected to water absorption and water absorption insulation performance tests. The experimental results indicated that the water absorption rate of the modified epoxy resin was reduced by 34.2%, resulting in a 25.2% reduction of the dielectric loss, an 11.6% increase of the breakdown strength, and a 98.3% increase of the volume resistivity. The satisfactory performance of the HTPDMS‐modified epoxy resin insulation material is attributed to the low surface energy and flexible SiO bond of the introduced HTPDMS. Simultaneously, the reduction of surface defects is also conducive to the epoxy resin insulation performance. Thus, HTPDMS‐modified epoxy resin insulation materials can maintain excellent insulation properties in humid environments, making them a promising application in the field of electronic packaging.

“…In the FTIR spectrum of SM, the absorption peaks at 1855 cm À1 and 1777 cm À1 correspond to the asymmetric and stretching vibrations of C═O in maleic anhydride, respectively. For SMO, the peak at 3452 cm À1 corresponds to an absorption peak of O H. [27][28][29] The absorption peaks of C═O in maleic anhydride disappeared, the absorption peak at 1720 cm À1 is the characteristic C═O stretching vibration of the ester group, and the absorption peaks at 1170 cm À1 and 1061 cm À1 are the C O C asymmetric stretching vibration and symmetric stretching vibration, respectively. The absorption peaks at 1643 cm À1 and 1400 cm À1 are assigned to C═O and C N stretching vibration of the amide group in SMN, the absorption peak at 3441 cm À1 represents the N H stretching band.…”

Section: Characteristics Of Rheology Modifiersmentioning

confidence: 99%

Lipophilic rheology modifier and its application in oil‐based drilling fluids

Zhou

2021

Control of rheological behavior plays an important role in the process of wellbore construction and ensure the success of drilling operation. This paper reports for the first time the use of poly-amide (SMN) and poly-ester (SMO) as potential rheology modifiers. Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance, and thermogravimetric analysis have been carried out to confirm the chemical structures and properties of SMN and SMO. The results from environmental scanning electron microscope (ESEM) illustrated that SMN and SMO are lamellar structures formed by the stacking or interpenetrating of thin sheets. The atomic force microscope test results show that the network structure is formed after dissolving rheology modifier in diesel oil. Combining with the rheology and suspension measurements, it can be determined that the addition of rheology modifier exhibited obvious influence on the viscosity, thixotropy, and settlement factor of W/O emulsion. The rheology control properties and suspension stability between two rheology modifiers and traditional rheology modifier organoclay were compared. After hot rolling at 180 C, the base mud containing organoclay exhibited excellent suspension stability, but the fluid had completely lost fluidity and consolidated into a block. For SMN and SMO addition into the base formula, the rheological parameters of base mud changed moderately and the settlement of barites was not observed after standing for 24 h.