Search

Showing total 3 results
Start Over Topic thermal treatment
3 results

1. Preparation and characterization of corn starch–calcium carbonate hybrid pigments.

Author

Kuusisto, Jonna and Maloney, Thad C.

Subjects
*CORNSTARCH, *CALCIUM carbonate, *PAPERMAKING, *MICROENCAPSULATION, *SCANNING electron microscopes, *PARTICLE size determination
Abstract

This article presents a novel method for integrating native corn starch and calcium carbonate (CaCO 3 ) into a hybrid pigment, which can be applied in papermaking to increase the amount of starch in paper and improve sheet bonding without impairing dewatering. Starch was first thermally treated to partially gelatinize and swell the granules. The aim of the treatment was to change the surface properties of starch and thus to improve the interaction with CaCO 3 particles. CaCO 3 shell was precipitated around the swollen granules and the encapsulated starch was then cooked to achieve complete gelatinization. When the granules were cooked, the starch became active for bonding, but its solubility was very limited due to the encapsulation. Particle size measurement and scanning electron microscopy were used to analyze the sample properties during the preparation. The hybrid pigment was added to paper sheets and its effect on the paper properties was examined. Starch was shown to be effectively bound to the pigment structure. The hybrid pigment allowed a large amount of native corn starch to be added to paper without interfering with the papermaking process. Furthermore, it gave excellent mechanical paper properties. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

2. Preparation and characterization of corn starch–calcium carbonate hybrid pigments

Author

Jonna Kuusisto and Thad Maloney

Subjects
Paper, 0106 biological sciences, Starch, Scanning electron microscope, Composite, 02 engineering and technology, 01 natural sciences, law.invention, chemistry.chemical_compound, Pigment, law, 010608 biotechnology, Botany, Thermal treatment, Solubility, Crystallization, ta215, Corn starch, Papermaking, food and beverages, 021001 nanoscience & nanotechnology, Dewatering, Calcium carbonate, chemistry, Chemical engineering, visual_art, visual_art.visual_art_medium, 0210 nano-technology, Agronomy and Crop Science
Abstract

This article presents a novel method for integrating native corn starch and calcium carbonate (CaCO3) into a hybrid pigment, which can be applied in papermaking to increase the amount of starch in paper and improve sheet bonding without impairing dewatering. Starch was first thermally treated to partially gelatinize and swell the granules. The aim of the treatment was to change the surface properties of starch and thus to improve the interaction with CaCO3 particles. CaCO3 shell was precipitated around the swollen granules and the encapsulated starch was then cooked to achieve complete gelatinization. When the granules were cooked, the starch became active for bonding, but its solubility was very limited due to the encapsulation. Particle size measurement and scanning electron microscopy were used to analyze the sample properties during the preparation. The hybrid pigment was added to paper sheets and its effect on the paper properties was examined. Starch was shown to be effectively bound to the pigment structure. The hybrid pigment allowed a large amount of native corn starch to be added to paper without interfering with the papermaking process. Furthermore, it gave excellent mechanical paper properties.

Published
2016

3. Characterization of purified bacterial cellulose focused on its use on paper restoration

Author

Sara M. Santos, Juan C. Villar, M. Eugenia Eugenio, Miguel Ladero, David Ibarra, Nuria Gómez, Ester Quintana, and José M. Carbajo

Subjects
Paper, Aging, Hot Temperature, Materials science, Polymers and Plastics, Characterization, Mineralogy, Thermal treatment, Degree of polymerization, Dynamic contact, Bacterial cellulose, Crystallinity, chemistry.chemical_compound, X-Ray Diffraction, Spectroscopy, Fourier Transform Infrared, Paper restoration, Materials Chemistry, Fourier transform infrared spectroscopy, Cellulose, Porosity, Purification, Ethanol, Viscosity, Organic Chemistry, Characterization (materials science), Gluconacetobacter, Chemical engineering, chemistry
Abstract

Bacterial cellulose (BC) synthesized by Gluconacetobacter sucrofermentans CECT 7291 seems to be a good option for the restoration of degraded paper. In this work BC layers are cultivated and purified by two different methods an alkaline treatment when the culture media contains ethanol and a thermal treatment if the media is free from ethanol. The main goal of these tests was the characterization of BC layers measured in terms of tear and burst indexes, optical properties, SEM, X-ray diffraction, FTIR, degree of polymerization, static and dynamic contact angles, and mercury intrusion porosimetry. The BC layers were also evaluated in the same terms after an aging treatment. Results showed that BC has got high crystallinity index, low internal porosity, good mechanical properties and high stability over time, especially when purified by the alkaline treatment. These features make BC an adequate candidate for degraded paper reinforcement. © 2014 Elsevier Ltd.

Published
2015