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Water Absorption Properties

Water absorption properties are mainly studied on the polymer composite system to find the effect of micro or nanoparticle incorporation in polymer matrix on water absorption behavior. Specimens of standard size and thickness are cut, finished on the sides and immersed in the liquid under standard conditions for several days. [Pg.334]

The water absorption behavior of the clay-epoxy nanocomposites in terms of maximum water uptake and diffusion coefficient are given in Table 9.18 [47]. The presence of nanoparticle as reinforcement reduces the water absorption of the composite system. The maximum water uptake of epoxy decreases gradually with the increase in clay content. The maximum water absorption decreases by 14.1,17.9 and 24.8% after the incorporation of 1, 3 and 5 wt% nano-clay, respectively, compared with neat epoxy. The presence of high aspect ratio nanofillers can create a tortuous pathway for water molecules to diffuse and enhances the resistance to water absorption. The diffusivity also decreases in the same manner and a significant reduction in diffusivity is obtained for the composites containing 5 wt% clay [112]. [Pg.334]

1 Effect of Water on the Mechanical Properties of Clay-Epoxy Nanocomposites [Pg.334]

The epoxy as well as nanocomposite samples kept in water medivun show a reduction in mechanical properties. The water absorption leads to plasticizing effect in the epoxy matrix, resulting in reduction in interfacial strength between the epoxy and reinforcing particles, which reduces flexural strength and modulus (Table 9.19). [Pg.334]

Sample Maximum Water Uptake (%) Diffusion Coefficient (10 mm Vs) [Pg.335]


GA is used as a stabilizer in frozen products like ice-cream due to its water absorption properties. The role of GA in these products is to cause a fine texture and growth by inhibiting the formation of ice crystals which is achieved by combining a large amount of... [Pg.9]

Field Pea Flour in Other Baked Products. When McWatters (44) substituted 8% field pea flour and 4.6% field pea concentrate for milk protein (6%) in baking powder biscuits, sensory attributes, crumb color, and density of the resulting biscuits were adversely affected. No modifications were made in recipe formulation when pea products were incorporated. The doughs were slightly less sticky than control biscuits that contained whole milk. This might be due to lack of lactose or to the different water absorption properties of pea protein or starch. Panelists described the aroma and flavor of these biscuits as harsh, beany and strong. Steam heating the field pea flour improved the sensory evaluation scores, but they were never equivalent to those for the controls. [Pg.32]

Raidl and Klein (43) substituted 5, 10, and 15% field pea flour in chemically leavened quick bread. The viscosity of the pea flour batters was significantly lower than either the wheat control or soy containing batters. The starch composition of the pea flour and lower water absorption properties of the protein could have affected the viscosity. Volumes of pea flour loaves were lower than the control and soy loaves. Most of the sensory characteristics of the field pea loaves were similar to those of the control quick breads. However, all flavor scores were significantly lower for pea flour products, since they had a recognizably beany or off-flavor. [Pg.32]

The water absorption properties of cellulose may be increased by grafting on polar groups, such as carboxyl groups, as in Super Slurpers, and this absorption may be decreased by the introduction of nonpolar moieties, such as ester groups, as in cellulose acetate. [Pg.207]

Fleming et al. (18) did not examine the effect of pH on water absorption, but these researchers examined the effect of "pH activation" on water absorption of sunflower and soy products. For pH activation, 1.25 N NaOH was added to slurries to achieve pH 12.2 and then 6.0 N HGl was added to return to pH 6.0 in 10 min. The pH activation process improved the water absorption properties for most products but did not increase water absorption of the soy flour. Processes similar to pH activation may be encountered in the processing of vegetable protein additives. [Pg.190]

Evaluation of water absorption properties of pastes in vitro this experiment was conducted as described in Reference 8. Briefly, 10 g of each paste were uniformly distributed on the bottom of a Petri dish, thereby ensuring that the surface of the paste was absolutely plain and unruffled. The preparation was covered with 20 ml of distilled water and left for 30 min at 20°C. The water was removed, and the surface of the product was dried with a soft tissue. The absorptive feature of the paste preparation was calculated from the weight... [Pg.280]

FIGURE 22.3 Water absorption properties of five hydrophilic (HP1 to HP5) and two lipophilic (LP1, LP2) pastes in vitro before and after drying to weight constancy n = 3, means + HSD. [Pg.282]

Surface-active agents are widely used in combination with other suppository bases. The inclusion of these agents in the formulation may improve the wetting and water-absorption properties of the suppository. In addition, emulsifying surfactants help to keep insoluble substances suspended in a fatty base suppository,... [Pg.3593]

Cetyl alcohol is also used for its water absorption properties in water-in-oil emulsions. For example, a mixture of petrolatum and cetyl alcohol (19 1) will absorb 40-50% of its weight of water. Cetyl alcohol acts as a weak emulsifier of the water-in-oil type, thus allowing a reduction of the quantity of other emulsifying agents used in a formulation. Cetyl alcohol has also been reported to increase the consistency of water-in-oil emulsions. [Pg.155]

Vermiculite resembles mica in appearance. In industrial process, vermiculite flakes are rapidly heated at flame temperature approaching 1000°C. Some of the water of hydration is removed and the pressure generated by the water vapor expands (or exfoliates) vermiculite particles which increases in volume by 15 to 20 times. This expansion process must be precisely controlled to achieve the required expansion and to retain its water absorption properties. If the time of heating is extended, vermiculite will no longer absorb water. Thus, different grades may be produced by varying the heating time. [Pg.165]

Salin compared the quality of particleboards manufactured from steam-dried versus air-dried wood particles [26] the bending and tensile strength, and water absorption properties of the former were found to be superior. This results in a 9% reduction in glue consumption in particleboard making. Optimal selection of dryer temperature and heat treatment... [Pg.428]

Helmet materials have ratings for weight, flammability, and water absorption properties. ANSI standards divide helmets into classes A, B, C, and D based on certain combinations of properties. [Pg.399]

Molecular weights available are 2000, 3000 and 5000, with the latter being preferred for the RIM-type processes. Of particular note is the low water absorption properties of these polyurea PUs. [Pg.351]

The selection of a suitable thermoplastic matrix material mostly depends on the desired mechanical properties and the desired long-term service temperature. Depending on the application area, there are other decision criteria known from thermoset matrix materials, which can be of major interest, for example the chemical resistance or the water absorption properties. In contrast, thermoplastic composites are normally featured with an improved toughness compared to their thermoset competitors. Table 8.2 gives an overview on properties of different common polymers which are used for the pultrusion process. [Pg.212]


See other pages where Water Absorption Properties is mentioned: [Pg.295]    [Pg.7]    [Pg.295]    [Pg.122]    [Pg.225]    [Pg.931]    [Pg.209]    [Pg.214]    [Pg.179]    [Pg.153]    [Pg.370]    [Pg.136]    [Pg.139]    [Pg.562]    [Pg.412]    [Pg.295]    [Pg.126]    [Pg.241]    [Pg.125]    [Pg.247]    [Pg.334]    [Pg.339]    [Pg.624]    [Pg.26]    [Pg.273]    [Pg.376]    [Pg.390]    [Pg.140]    [Pg.54]    [Pg.301]    [Pg.74]    [Pg.460]   


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