Impregnation of paper with cellulose nanofibrils and polyvinyl alcohol to enhance durability

2020 ◽  
Vol 35 (1) ◽  
pp. 106-114
Author(s):  
Hyeonji Park ◽  
Shin Young Park ◽  
Simyub Yook ◽  
Tae-Young Kim ◽  
Hye Jung Youn
Keyword(s):  
Polyvinyl Alcohol ◽  
Mechanical Strength ◽  
Shear Viscosity ◽  
Cellulose Nanofibrils ◽  
Control Sample ◽  
High Mechanical Strength ◽  
Base Paper ◽  
Low Shear Viscosity ◽  
Impregnation Solution ◽  
Low Shear

AbstractDurable papers should exhibit high mechanical strength and good soiling resistance. In this study, cellulose nanofibrils (CNF) was investigated as an additive to the polyvinyl alcohol (PVA) impregnation solution to improve the durability of paper. The impregnation suspensions were prepared by adding CNF to PVA solution in various ratios, and were used to impregnate a base paper. The PVA-CNF suspensions exhibited good dispersion stability; however, the low shear viscosity increased as its CNF content increased. The pickup weights of the papers impregnated with the PVA-CNF suspensions were found to be lower than those of the control sample, which were impregnated with the pure PVA solution only. Although the strength of the paper was not significantly improved by the addition of CNF, when the paper was impregnated with a PVA-CNF suspension containing 5 % CNF content, the product exhibited similar strength to the papers impregnated with only a 3 % PVA solution despite its lower pickup weight. The mechanical strength of the impregnated paper was affected by the pickup weight and penetration of the impregnating agent. The addition of a wet strengthening agent to the mixed suspensions was seen to enhance the wet soiling resistance of the papers.

Low shear viscosity of polypropylene melts

1963 ◽  
Vol 1 (7) ◽  
pp. 381-384 ◽  
Author(s):  
D. Poller ◽  
A. M. Kotliar ◽  
R. L. Kruse
Keyword(s):  
Shear Viscosity ◽  
Low Shear Viscosity ◽  
Low Shear

scholarly journals Cement-Based Materials Containing Graphene Oxide and Polyvinyl Alcohol Fiber: Mechanical Properties, Durability, and Microstructure

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 638 ◽  
Author(s):  
Wenguang Jiang ◽  
Xiangguo Li ◽  
Yang Lv ◽  
Mingkai Zhou ◽  
Zhuolin Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Flexural Strength ◽  
Polyvinyl Alcohol ◽  
Mechanical Strength ◽  
Mechanical Performance ◽  
Control Sample ◽  
Corrosion Condition ◽  
Cement Based Materials ◽  
Strength And Durability ◽  
Pva Fiber

The influence of graphene oxide (GO) and polyvinyl alcohol (PVA) fiber on the mechanical performance, durability, and microstructure of cement-based materials was investigated in this study. The results revealed that compared with a control sample, the mechanical strength and durability of cement-based materials were significantly improved by adding PVA fiber and GO. The compressive and flexural strength at 28 d were increased by 30.2% and 39.3%, respectively. The chloride migration coefficient at 28 d was reduced from 7.3 × 10−12 m2/s to 4.3 × 10−12 m2/s. Under a sulfate corrosion condition for 135 d, the compressive and flexural strength still showed a 13.9% and 12.3% gain, respectively. Furthermore, from the Mercury Intrusion Porosimetry (MIP) test, with the incorporation of GO, the cumulative porosity decreased from more than 0.13 cm3/g to about 0.03 cm3/g, and the proportion of large capillary pores reduced from around 80% to 30% and that of medium capillary pores increased from approximately 20% to 50%. Scanning electron microscope (SEM) images showed a significant amount of hydration products adhering to the surface of PVA fiber in the GO and PVA fiber modified sample. The addition of GO coupling with PVA fiber in cement-based materials could promote hydration of cement, refine the microstructure, and significantly improve mechanical strength and durability.

Dispersion and Rheological Properties of Alumina Freeze Casting Slurries Containing Nanoparticle/Whisker SiC

2007 ◽  
Vol 280-283 ◽  
pp. 1035-1038 ◽  
Author(s):  
Tae Young Yang ◽  
Young Min Park ◽  
Gun Dae Lee ◽  
Seog Young Yoon ◽  
Ron Stevens ◽  
...  
Keyword(s):  
Shear Rate ◽  
Shear Viscosity ◽  
Pure Alumina ◽  
Rheological Measurements ◽  
Continuous Shear ◽  
Suspension Viscosity ◽  
Low Shear Viscosity ◽  
Opposite Manner ◽  
High Structure ◽  
Low Shear

The sedimentation density significantly decreased after addition of dispersant; the effect was more pronounced with pure alumina, as compared with SiC-containing slurry. With further addition of surfactant, the sedimentation density increased somewhat, but decreased with binderadditions. The suspension viscosity generally behaved in an opposite manner to the sedimentation density, i.e., low sedimentation density gave high low-shear viscosity, indicative of high structure formation in the suspended particles. Shear rate rheological measurements showed continuous shear thinning behavior.

The Measurement of Viscosity of Liquids Under Tension

2003 ◽  
Vol 125 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Peter A. Kottke ◽  
Scott S. Bair ◽  
Ward O. Winer
Keyword(s):  
Shear Viscosity ◽  
Initial Pressure ◽  
Viscosity Coefficient ◽  
Absolute Zero ◽  
Viscosity Data ◽  
Hydrostatic Tension ◽  
Low Shear Viscosity ◽  
Low Shear

The rheological significance of a state of hydrostatic tension was investigated. A method for measuring the limiting low shear viscosity of liquids under tension was developed. The ability of nine liquids to withstand tension was verified, and the magnitudes of tension achievable through different methods were compared. The use of viscosity data from liquids under tension to more accurately determine the initial pressure viscosity coefficient was investigated. The continuity of the pressure viscosity coefficient across absolute zero pressure was verified.

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