Influence of Viscosity and Magnetoviscous Effect on the Performance of a Magnetic Fluid Seal in a Water Environment

<p>The magnetic fluid seal is one of the most successful applications of magnetic fluids. The theory of magnetic fluid seals in liquid environments has not been developed. This work mainly presents an experimental study of the influence of viscosity and magnetoviscous effects on the performance of a magnetic fluid seal in a water environment. Three engine oil–based magnetic fluids of different viscosities and similar saturation magnetization values were prepared and a multistage magnetic seal structure was designed. The magnetoviscous effect of the magnetic fluids under different working conditions was measured with an advanced rotational rheometer. An experimental platform and a multistage magnetic seal structure were designed for the critical pressure value and durability tests. The experimental results show that the viscosity of a magnetic fluid is a decisive factor in its sealing performance under a water environment and a discussion is presented that can explain the experimental results qualitatively.</p

Tensile stress-strain curves of PLA plasticized by PEG with different molecular weight.

<p>Tensile stress-strain curves of PLA plasticized by PEG with different molecular weight.</p

Thermogravimetric curves of the composites with different contents of PEG 2000.

<p>Thermogravimetric curves of the composites with different contents of PEG 2000.</p

Preparation of plasticized poly (lactic acid) and its influence on the properties of composite materials - Fig 1

<p>ATR-FTIR spectra of (A) the native PLA, PEG 400, PPLA 400 and (B) PPLA with different <i>M</i>_w: (a) neat PLA, (b)PPLA 400, (c) PPLA 1000, (d) PPLA 2000, (e) PPLA 4000.</p

Preparation of plasticized poly (lactic acid) and its influence on the properties of composite materials - Fig 6

<p>DSC curves of: A. pure PLA; B. PPLA 400: (a) the first heating curve, (b) cooling curve, and (c) the second heating curve.</p

Preparation of plasticized poly (lactic acid) and its influence on the properties of composite materials - Fig 7

<p>(A) <i>T</i>_g. (B) <i>T</i>_c and (C) <i>χ</i>_c of PLA blended with 10 wt% PEG at various <i>M</i>_ws (from the second heating curve): (●) neat PLA, (◆) PPLA.</p

Flexural strength and moduli of PLA plasticized by PEG with different molecular weight.

<p>Flexural strength and moduli of PLA plasticized by PEG with different molecular weight.</p

Preparation of plasticized poly (lactic acid) and its influence on the properties of composite materials - Fig 5

<p>Thermogravimetric curves of: (A) TGA-DTG curves for pure PLA, PEG 400 and PPLA 400. (B) pure and plasticized PLA.</p

DSC traces (the second heating) of the melting behavior of the composites with different amounts of PEG2000.

<p>DSC traces (the second heating) of the melting behavior of the composites with different amounts of PEG2000.</p

Mechanical strength of PLA/WF composites with different amounts of PEG2000.

<p>Mechanical strength of PLA/WF composites with different amounts of PEG2000.</p