Formation of Phenoxynorbornane Pendant Groups by Acid-Catalyzed Hydroalkoxylation of Poly(hydroxystyrene) and Its Application to Photopatterning.

Poly(hydroxystyrene) (PHS) reacts with norbornene in the presence of acid to form a phenoxynorbornane pendent group through the hydroalkoxylation of the norbornene double bond by the phenol -OH group of PHS. Films of PHS, an aqueous base soluble polymer, containing norbornene derivatives and a photoacid generator (PAG) create a negative tone photopatternable composition. Acid generated in the exposed regions of the film promotes the hydroalkoxylation reaction generating the phenoxynorbornane pendent group, rendering the film insoluble in an aqueous base developer. Both dinorbornene and mononorbornene-functional additives were evaluated. In the case of the mononorbornene additive, a unique example of a negative tone photopatterned film that can be reworked after patterning by dissolution in a mild solvent at room temperature was demonstrated. Polymers containing aliphatic alcohol and carboxylic acid pendant functionalities could be photopatterned in the presence of dinorbornene additives showing the generality of this method.

Characterization of sugars from model and enzyme-mediated pulp hydrolyzates using high-performance liquid chromatography coupled to evaporative light scattering detection.

High-performance liquid chromatography (HPLC) coupled to an evaporative light scattering detector was used to quantitatively determine glucose and cellobiose in hydrolyzates from the production of cellulose nanofillers from modified lignocellulosic materials. Prevail Carbohydrate ES 5 micron column proved more suitable for achieving the chromatographic separation of the model pulp hydrolyzate into its constituent sugars than the YMC-Pack Polyamine column. Linear calibration curves for the various sugars in the mixtures were developed. Glucose and cellobiose were clearly detectable in pulp hydrolyzates obtained from enzyme-mediated hydrolysis of recycled pulp, pine and hardwood dissolving pulps. Finally, the amount of glucose in the pulp hydrolyzates was generally higher than cellobiose.

Sono-chemical preparation of cellulose nanocrystals from lignocellulose derived materials.

This study examined the production of cellulose nanocrystals from microcrystalline wood cellulose, Avicel and recycled pulp of wood pulp using sono-chemical-assisted hydrolysis. Two hydrolysis systems: deionized water and maleic acid were evaluated. In deionized water, Avicel produced cellulose nanocrystals with average diameter of 21+/-5 nm (minimum 15 nm and maximum 32 nm). Cellulose nanocrystals from recycled pulp were not distinctively spherical and had an average diameter of 23+/-4 nm (minimum 14 nm and maximum 32 nm). Maleic acid (50 mM) sono-chemical assisted hydrolysis of Avicel at 15 degrees C and 90% power output for 9 min produced cellulose nanocrystals which were cylindrical in shape and were of dimensions, length 65+/-19 nm and width 15 nm.