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Polymer chain mobility and film softness have been demonstrated to determine protein adsorption at the solid–liquid interface, and even overwhelm the hydrophilic effect under certain conditions. Polymers with high chain mobility and softness provide superior protein antifouling properties as a result of the high entropy barrier from film surfaces.

This paper aims to develop a mathematical model for investigating the nonlinear dynamic mixed friction behaviors, including hydrodynamic, contact, deformation, etc., of the novel coupled bearing lubricated with low-viscosity fluid. The model fully integrates the five-degrees-of-freedom (5-DOF) rotor dynamic model with the mixed elastohydrodynamic lubrication model of the novel coupled bearing, considering the unbalance and exciting forces/comments caused by the propeller rotor. A comparative analysis is carried out to validate the effectiveness of the present model. Through the numerical simulation, the dynamic nonlinear mixed friction behaviors of the novel coupled bearing under low-viscosity lubricant are revealed. Based on the established mathematical model, a series of parametric studies are conducted to explore the effect of the structural parameters on the nonlinear mixed friction behavior of the novel coupled bearing. Numerical results demonstrate that the exciting moments increase the range of the axis orbit, thereby generating the edge asperity contact for both the journal and thrust bearings. The angular displacement along the y-axis improves the transient mixed friction performances of the thrust bearing. Furthermore, numerical results reveal that the increasing length-diameter ratio of the journal bearing (the specific pressure remains constant) improves the nonlinear dynamic mixed friction behaviors of the thrust bearing. In addition, the nonlinear dynamic mixed friction performance of the journal bearing becomes better with the increase in the thrust bearing radius.

Polystyrene (PS) was synthesized by emulsion polymerization. 1,4-bis(chloromethoxy)butane (BCMB) was synthesized using 1,4-butanediol, formaldehyde and phosphorus trichloride as raw material. The linear poly(p-chloromethyl styrene) (PS-Meyl-Cl) was prepared high effectively using BCMB and anhydrous aluminium trichloride as the chloromethylation reagent and catalyst, respectively. In this method, carcinogenic compound (chloromethyl ether etc.) was avoided. The resultant polymers were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectrometer (FTIR) and thermogravimetric analyzer. The results show that the molecular weight (Mw) of PS is big. BCMB has been prepared because of the strong absorption band observed at 1130cm-1 (due to C-O-C bond stretching vibration) and two new bands at 640 and 1315cm-1 (due to the bending vibration of C-Cl bond and stretching vibration of C-H bond in -CH2Cl, respectively). Chloromethyl groups were introduced into benzene ring of PS because of the appearance of the absorption peaks at 676 and 1419cm-1 (due to the bending vibration of C-Cl bond and stretching vibration of C-H bond in -CH2Cl, respectively) in the FTIR spectra. The thermal stability of PS-Meyl-Cl was decreased with increasing chloromethyl group. Moreover, there are two decomposing stages. The reaction condition is gentle and the operation is safe, simple and economical.