Small Angle Neutron Scattering Reveals Wood Nanostructural Features in Decay Resistant Chemically Modified Wood

While it is known that modifying the hydroxyls in wood can improve the decay resistance; what is often missing in the literature is whether these modifications alter wood nanostructure, and how these changes correlate to the improved decay resistance. Here, we used small angle neutron scattering (SANS) to probe the effects of alkylene oxide modifications on wood nanostructure. Southern pine wood samples were chemically modified to various weight percentage gains (WPG) using four different alkylene oxides: propylene oxide (PO), butylene oxide (BO), epichlorohydrin (EpH), and epoxybutene (EpB). After modification, the samples were water leached for 2 weeks to remove any unreacted reagents or homopolymers and then equilibrium moisture content (EMC) was determined at 90% relative humidity (RH) and 27°C. Laboratory soil block decay evaluations against the brown rot fungus Gloeophyllum trabeum were performed to determine weight loss and biological efficacy of the modifications. To assist in understanding the mechanism, SANS was used to study samples that were fully immersed in deuterium oxide (D2O). These measurements revealed that the modifications altered the water distribution inside the cell wall, and the most effective modifications reduced the microfibril swelling and preserved the microfibril structure even after being subject to 12 weeks of brown rot exposure.

Efficacy and safety of a novel hemostatic material, BoneStat, compared with Ostene and Bone Wax in a rat calvarial defect model

Hemostasis has critical significance during surgical procedures. Bone Wax has traditionally been commonly used for bone hemostasis despite well-documented undesirable side effects: hindering osteogenesis and induction of inflammatory reactions with consequent increase in infection rates. A later developed formulation, Ostene, offers an alternative to Bone Wax with lesser undesired effects. In this study, BoneStat, a newly developed bone hemostatic formulation comprising water-soluble alkylene oxide co-polymers, was evaluated for water solubility, hemostatic efficacy, ease of handling, bone healing efficacy, and inflammatory reactions compared with Bone Wax and Ostene in a rat calvarial defect model. More than 95% of BoneStat was dissolved in water within 48 h, as was Ostene, but not Bone Wax. The time to hemostasis using BoneStat was significantly faster than with Ostene or Bone Wax. BoneStat also improved ease of handling compared to Ostene or BoneWax. BoneStat- and Ostene-treated groups constantly showed better bone healing than with Bone Wax. The BoneStat and Ostene groups presented no evidence of chronic inflammation reaction contrary to Bone Wax. These results suggest improved hemostasis, ease of handling, non-hindering bone healing, and unnoticeable chronic inflammatory reactions with BoneStat. Thus, Bonestat is a useful and reliable formulation for mechanical hemostasis.

Elastic strain-hardening and shear-thickening exhibited by thermoreversible physical hydrogels based on poly(alkylene oxide)-grafted hyaluronic acid or carboxymethylcellulose

An alternative interpretation of the transient network theory is necessary to explain the evolution of the viscoelastic parameters during the temperature-dependent formation into a solid gel structure.

Study on flame retardant ABS

Flame-retardant ABS resin was prepared by adding fl ame retardant, toughening agent and dispersing silicone oilwith acrylonitrile-butadiene-styrene resin (ABS, grade 0215 A) as raw material. The results showed that in the ABSresin, fl ame retardant with tetrabromobisphenol A and antimony trioxide as the composite system (the mass ratio of2:1) was added. When the bromine content of the system was more than 10%, the flame retardant ABS meets therequirements of UL 94 V-0. The best toughening agent for flame retardant ABS resin is ABS graft powder. Whenthe amount of fl ame retardant ABS is 9% ~ 19% (mass fraction) Strength of 150-200 J / m; in the same formula andoperating conditions, brominated alkylene oxide as fl ame retardant prepared fl ame retardant ABS resin, the weatherresistance is better than tetrabromobisphenol A as fl ame retardant The Composite expansion fl ame retardant and coatedred phosphorus is an eff ective halogen-free fl ame retardant.