Green Modification of Cellulose Nanocrystals and Their Reinforcement in Nanocomposites of Polylactic Acid

Cellulose nanocrystals （CNCs） of rod-like shape were prepared from degreased cotton using sulfuric acid hydrolysis. The obtained CNC suspension was neutralized using a sodium hydroxide solution to remove the residual sulfuric acid and improve the thermal stability of the CNC particles. Then, poly（ethylene oxide） （PEO） was employed to modify the nanocrystals through entanglement and physical adsorption. The goal was to further improve the thermal stability and weaken the hydrophilicity of CNCs. Original and modifed CNCs were dosed into a polylactic acid （PLA） matrix to prepare nanocomposites using a hot compression process. Results of the thermogravimetric analysis showed that the initial thermal decomposition temperature of the modifed CNCs showed a 120℃ improvement compared to the original CNCs. That is, the thermal stability of the modified CNCs improved because of their shielding and wrapping by a PEO layer on their surface. Results from scanning electron microscopy and ultraviolet-visible spectrophotometry showed that the compatibility of the modifed CNCs with organic PLA improved, which was attributed to the compatibility of the PEO chains adsorbed on the surface of the CNCs. Finally, the results of tensile tests indicated a significant improvement in terms of breaking strength and elongation at the break point.

Vitamin E-derived copolymers continue the challenge to hemodialysis biomaterials

Improving material biocompatibility has been a continu-ous effort and remains a major goal of dialysis therapy. In this respect, vitamin E-modified copolymers have been used to produce a generation of biomaterials that has offered new clinical challenges and the chance of further improving the quality of synthetic hemodialyser membranes. This mini review article describes the evo-lution of these copolymers that only recently have been adopted to develop new vitamin E-modifed polysulfone hemodialysers. Biomaterial characteristics and clinical aspects of these membranes are discussed, starting from the most recent contributions that have appeared in the literature that are of interest for the community of nephrology and dialysis specialists, as well as bioma-terial scientists.

Development of Porous Spherical Cellulose Bead Production from Corn Cob as an Exfoliating Agent for Cosmetic Industries

The aim of this research was to develop the porous spherical cellulose production from corn cob as an exfoliating agent for cosmetic industries. In process development of the porous spherical cellulose production from corn cob, it was found that alkaline extraction with 10% sodiumhydroxide gave 85.86% purity of cellulose and the crystallinity index of the pulp of 76.08%. Then, the obtained pulp was extracted with acid sodium chlorite. It was found that the acid sodium chlorite extraction increased the cellulose from 85.86% to 91.86%. The obtained pulp was hydrolyse dwithdilute hydrochloric solution. The result shows that the crystallinity increased from 71.13% to 86.31% with smaller crystallite size compared to that obtained acid sodium chlorite extraction. The hydrolysis pulp was used to prepare porous spherical cellulose which has homogeneous and rough surface. The porosity and pore volume of the porous spherical cellulose increased when the amount of calcium carbonate as porogen was increased. The porous spherical cellulose was prepared from the optimized conditions and the physical and chemical properties were analysed and compared with standard commercial beads （Sephadex G-25）. It was found that the porous spherical cellulose had particle size and pH value similar to the standard value. Hazardous substances such as arsenic, lead and mercury were not found in the obtained porous spherical cellulose. The consumers test shows that 87~/＇0 of consumers accepted the product and the overall complacency was great.

Optimization of Micro Crystalline Cellulose Production from Corn Cob for Pharmaceutical Industry Investment

MCC （micro crystalline cellulose） is a very important product in pharmaceuticals, foods, cosmetics and other industries. MCC can be made from any natural cellulose materials that have high content of cellulose ranging from pure cellulose, commercial grade cellulose to lignocellulosic materials. In this work, Beeswing （-20 L） and Chaff （5/8） which are the parts of corn cobs were used as raw materials to produce MCC via alkaline degradation, bleaching and hydrolysis. The optimum conditions of alkaline degradation, bleaching and hydrolysis were studied. MCC samples that prepared from -20 L and 5/8 were characterized through XRD （X-ray diffraction）, SEM （scanning electron microscopy） and compared with the commercial MCC （Avicel PH 101）. The results show that the degree of crystallinity of alkaline degradation, bleaching and hydrolysis obtained at 10% of NaOH 95 ~C for 2 h, NaCIO21.5 g 10% of acetic acid 0.5 mL 70 ~C for 2 h, 2 N of HC1, 105 ~C for 1 h showed maximum values which are 77.07%, 75.07% and 86.84%, respectively. The degree of crystallinity and the morphology of prepared MCC correspond to that of Avicel PH 101 industrial investment has been studied, the benefits of micro crystalline cellulose production （MCC） is 3,447 baht/kg. The investment of the plant is 7,263,514 baht and the breakeven point is around 6 years.