Cationic starch adsorption onto cellulosic pulp in the presence of other cationic synthetic additives

Enzyme activity test paper with high wet strength and anion adsorption properties fabricated from whole cationized softwood chemical fiber

Paper-based test film material is widely used in a variety of test instruments for different applications. The enzyme activity test paper sheet is one of the most popularly used test papers. Here we present a novel fabrication of paper-based enzyme activity test paper without cationic resin added in. The chemical pulping fibers were first beaten to different degrees (from 14.6 to 41.5°SR) with a PFI beater. After that, the fibers were modified with a cationic agent (3-chloro-2-hydroxypropyl trimethyl ammonium chloride) under the system of alkali and water solution. Finally, the test papers were made with the modified fiber by a regular paper former in lab. The results showed that beating is beneficial for the improvement of the cationization reaction which is indicated by the Zeta potential, FTIR and EDS. The main mechanisms involved are the destruction of crystalline zone, increase of free hydroxyl group and defibrillation. This hypothesis was supported by the SEM, XRD and fiber analyzer. Beating under the optimized condition, the wet strength and liquid absorbability of test paper can meet the application requirement, and the test results of enzyme activity are quite close to those of commercial test papers.

Valorization and Development of Acorn Starch as Sustainable and High-Performance Papermaking Additive for Improving Bagasse Pulp and Paper Properties

Improving bagasse pulp and paper properties using forest-byproduct biomass, native Acorn starch (NAS), was compared with conventional wet-end additive cationic corn starch (CCS). The extracted acorn starch was characterized by SEM, XRD, and GPC. The results clearly showed irregular granular shape (6-12 μm) with rough surfaces, C_A-type XRD pattern, and 436.2 kDa molecular weights for NAS. The bagasse pulp retention and drainage as keys of operation performance and runnability were superior by NAS in comparison with CCS, while the lowest dosage of NAS (0.5%) showed superior results than the highest dosages of CCS (1% & 1.5%). The higher NAS adsorption onto the fiber surfaces compared to CCS could be concluded by higher water retention value (WRV) of the pulp together with higher density (up to 20%) and mechanical properties of the produced paper, e.g., tensile (up to 63%), burst (up to 37%) and tear (up to 11%) indices. NAS exploiting naturally as a papermaking additive would provide performance higher than commercial chemically-modified starch.

Investigation of the Adsorption Behavior of Jet-Cooked Cationic Starches on Pulp Fibers

The optimization of the thermal treatment of cationic starch in the paper industry offers the opportunity to reduce the energy consumption of this process. Four different industrially relevant cationic starches, varying in source, cationization method and degree of substitution were treated by a steam-jet cooking procedure, comparable to industrially employed starch cooking processes. The influence of the starch properties and cooking parameters on the adsorption behavior of the starches on cellulosic pulp was investigated. The adsorbed amount was affected by the cooking temperature and the type of starch. For some starch grades, a cooking temperature of 115 °C can be employed to achieve sufficient starch retention on the pulp fibers. The energy consumption could further be reduced by cooking at higher starch concentrations without loss of adsorption efficiency.

Characterization and Quantification of Polyquaterniums via Single-Use Polymer Membrane-Based Polyion-Sensitive Electrodes

Two facile, robust, and universal methods by which various polymeric quaternary ammonium salts (polyquaterniums (PQs)) can be quantified and characterized using simple potentiometric polymeric membrane polyion-sensitive electrodes as detectors are described. The two methods are (a) direct detection with polycation sensitive membrane electrodes based on the sodium salt of dinonylnaphthalenesulfonate (NaDNNS), and (b) indirect detection using polyanion sensors based on tridodecylmethylammonium chloride (TDMAC) and dextran sulfate (DS) as a titrant to complex the various polyquaternary species (four different PQs: PQ-2, PQ-6, PQ-10, and poly(2-methacryloxyethyltrimethylammonium) chloride (PMETAC)). Direct detection yields information regarding the charge density of the polycationic species. For the titration method, a series of polyanion sensors doped with TDMAC are used to follow a potentiometric titration of a PQ species using a syringe pump to deliver the titrant. This indirect detection method is more reliable and yields limits of detection in the ppm range for the four PQs examined. The titration method is further explored for detecting excess levels of PQ-6, a common flocculating agent for municipal water supply systems, within the purified water emitted by the Ann Arbor, MI, drinking water treatment plant.