Die-less wire drawing using polymer fluids

A die-less wire drawing process has been developed in order to investigate the performance on the reduction of wire size of polymer coating on steel wire. Previous experimental investigations have shown significant reductions in area particularly using nylon and borosiloxane on copper wire. The present investigation shows that satisfactory reductions can also be obtained using these polymers on steel wire. A smooth adhered coating of the wire was produced with the nylon; however, drawing speed limitations were observed where break up of the coatings occurred.     

Studies on adhesion performance of addition-curable liquid silicone rubber on epoxy networks treated with different structures borosiloxane oligomers

In this investigation, 3-glycidoxypropyltrimethoxysilane and boric acid with the molar ratio of 1, 2, and 3 were used to synthesize different structures borosiloxane oligomers (BSiO-1, BSiO-2, and BSiO-3). The structures of these borosiloxane oligomers were evaluated by the gel permeation chromatography, the Fourier transform infrared spectroscopy, the nuclear magnetic resonance spectroscopy, and the thermogravimetric analysis. The influence of borosiloxane oligomers structures on adhesion between addition-curable liquid silicone rubber and epoxy networks was investigated by pull-out test. Results showed that BSiO-1 and BSiO-2 exhibited excellent adhesive property with the adhesion strength being increased from 0.02 to 0.18?MPa, whereas BSiO-3, with an adhesion strength value of 0.1?MPa, displayed a slightly inferior adhesive characteristic. Field emission scanning electronic microscopy revealed the attenuation of adhesive characteristic of BSiO-1, BSiO-2, and BSiO-3 in turn, and an adhesive attenuation mechanism was proposed.     

Synthesis and characterization of novel borosiloxane‐containing aromatic copolyimides with excellent thermal stability and low coefficient of thermal expansion

The properties of borosiloxane‐containing copolyimides with borosiloxane in the main chain and in the side chain were studied. Two series of borosiloxane‐containing copolyimides were synthesized by the reaction of 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (s‐BPDA ) and 2,3′,3,4′‐biphenyltetracarboxylic dianhydride (a‐BPDA ) with p ‐phenylenediamine (PDA ), 4,4′‐oxydialinine (4,4′‐ODA ) and different borosiloxane diamine monomers (BSiAs ). The synthesized borosiloxane‐containing copolyimides exhibited better solubility than borosiloxane‐free copolyimides and showed high glass transition temperatures (320–360 °C), excellent thermal stability (570–620 °C for T ₁₀), great elongation at break (10% ? 14%) and a low coefficient of thermal expansion (14–24 ppm °C^?1). More specifically, the copolyimides containing BSiA‐2 formed nano‐scale protrusions and the copolyimides containing BSiA‐1 formed micro‐scale protrusions. The contact angles of the copolyimides increased from 72° for neat copolyimide to 96° for 5% of borosiloxane in the main chain of the copolymer up to 107° for 10% of borosiloxane in the side chain of the copolymer. © 2017 Society of Chemical Industry     

Preparation and properties of borosiloxane gels

Hybrid gels were synthesized from modified silicon alkoxides (R‐Si(OEt)₃, R?H, Me, Vi) and triiso‐butylborate (B(O? R′)₃, R′ = isoBu). The obtained gels were characterized by Fourier‐transform infrared (FTIR), nuclear magnetic resonance (NMR), elemental analyses, X‐ray diffraction (XRD), and scanning electron microscopy (SEM). Boron atoms in the precursors were homogeneously dispersed in the siloxane network via Si? O? B bonds. The effect of the boron load on oxidation resistance of the gels, and the pyrolysis behavior of the borosiloxane gels with different substituents on silicon, were investigated using various techniques. The experimental results suggest that the addition of a proper fraction of boron alkoxide to the precursors can improve the oxidation stability of the gels, and decrease the weight loss of the samples to 6.9 wt % at 1000°C under air. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 719–724, 2006