Char-forming behavior of nanofibrillated cellulose treated with \u3ci\u3eglycidyl phenyl\u3c/i\u3e POSS

Cellulose-reinforced composites have received much attention due to their structural reinforcing, light weight, biodegradable, non-toxic, low cost and recyclable characteristics. However, the tendency for cellulose to aggregate and its poor dispersion in many polymers, such as polystyrene, continues to be one of the most challenging roadblocks to large scale production and use of cellulose-polymer composites. In this study, nanofibrillated cellulose (NFC) is modified using GlycidylPhenyl-POSS (a polyhedral oligomeric silsesquioxane). The product yield, morphology, and crystallinity are characterized using a variety of spectroscopy and microscopy techniques. Thermal analyses are performed using thermal gravimetric analysis and pyrolysis combustion flow calorimetry

Synthesis of SiCl₄ via the Chloride Salt-Catalyzed Reaction of Orthosilicates with SOCl₂

This paper details a method to chlorinate tetraalkyl orthosilicates in the presence of a catalyst using SOCl₂ as the chloride source/deoxygenating agent. Several inexpensive catalysts were screened, and it was found that soluble chloride salts performed better than Lewis base catalysts. The optimized reaction employed a widely used and commercially available soluble chloride salt catalyst (e.g., NBu₄Cl, 0.4 equiv), 16 equiv of SOCl₂, and afforded quantitative yield of SiCl₄ after 3 h. As the bulk of the orthosilicate substrate increased, the yield of SiCl₄ decreased. A reaction mechanism has been proposed

Synthesis of SiCl₄ via the Chloride Salt-Catalyzed Reaction of Orthosilicates with SOCl₂

This paper details a method to chlorinate tetraalkyl orthosilicates in the presence of a catalyst using SOCl₂ as the chloride source/deoxygenating agent. Several inexpensive catalysts were screened, and it was found that soluble chloride salts performed better than Lewis base catalysts. The optimized reaction employed a widely used and commercially available soluble chloride salt catalyst (e.g., NBu₄Cl, 0.4 equiv), 16 equiv of SOCl₂, and afforded quantitative yield of SiCl₄ after 3 h. As the bulk of the orthosilicate substrate increased, the yield of SiCl₄ decreased. A reaction mechanism has been proposed

Study on the Shock Sensitivity of the Hydrolysis Products of Hexachlorodisilane

The hydrolysis products of hexachlorodisilane (HCDS) show common heat sensitivity and can become shock sensitive under certain conditions. Study of the shock sensitivity has been difficult due to the unpredictable nature of this phenomenon. We have identified the parameters affecting the shock sensitivity of the materials and developed synthetic methods to consistently prepare the hydrolysis products with a high shock sensitivity. We characterized the composition of the hydrolysis products to be [SiO_<i>x</i>(OH)_{4–2<i>x</i>}]_<i>m</i>­[Si₂O_<i>y</i>(OH)_{6–2<i>y</i>}]_<i>n</i>­(H₂O)_<i>o</i> where <i>x</i> is 0–2, <i>y</i> is 0–3, <i>m</i> is less than <i>n</i>, and <i>o</i> varies. The hydrogen atoms in the silanol groups or absorbed water are the oxidant and the silicon atoms in the Si–Si bonds are the reductant. When the materials are disturbed by a thermal or mechanical impact, fast redox reactions happen to form molecular hydrogen. A sequence of free radical reactions was proposed to explain the shock sensitivity and shock-induced chemical transformation