what fibres are present in a plant
Answers
Answer:
Plant Fibers. With the exception of synthetic polymers, most economically important products, such as paper, cordage (cords and rope) and textiles, are derived from plant fibers. Fibers are elongate cells with tapering ends and very thick, heavily lignified cell walls.
Explanation:
Answer:
Plant fibers are hydrophilic owing to the presence of functional groups such as hydroxyl in their structure.110 Therefore, plant fibers absorb a considerable amount of moisture from the surrounding environment. The moisture absorption capacity of plant fibers depends mainly on their chemical composition and crystallinity. Table 13.5 lists the moisture absorption of some selected plant fibers.110
The high moisture absorption of plant fibers leads to a number of problems when used for the reinforcement of cementitious materials such as85,110: (1) plant fibers swell due to absorption of moisture and shrink when moisture is removed due to dry atmosphere and elevated temperatures. Then, when plant fibers are used to reinforce cementitious matrix, their frequent swelling–shrinking phenomena leads to formation of cracks. This leads to reduced mechanical performance and durability of cementitious composites. (2) High absorption of alkaline solution present within the cement mixture leads to degradation of plant fibers with time. These result in the deterioration of properties of plant fibers as well as plant fiber-reinforced cementitious composites. (3) If plant fibers are not saturated, during mixing with cementitious materials they absorb considerable amount of water and reduce the water required for cement hydration. This leads to a reduced degree of cement hydration and, consequently, poor mechanical performance of cementitious composites. (4) Moisture absorption of plant fibers leads to breakage of hydrogen bonds between the fiber and cementitious matrix and, therefore, weakens the fiber/matrix interface and, consequently, it deteriorates mechanical strength. Therefore, a number of fiber surface treatment methods have been tried to reduce the moisture absorption of plant fibers for applying them in cementitious composites.
Explanation: