Natural fibers today are a popular choice for applications in composite manufacturing.Based on the sustainability benefits, biofibers such as plant fibers are replacing synthetic fibers in composites. These fibers are used to manufacture several biocomposites. The chemical composition and properties of each of the fibers changes, which demands the detailed comparison of these fibers. The reinforcement potential of natural fibers and their properties have been described in numerous papers. Today, high performance biocomposites are produced from several years of research. Plant fibers, particularly bast and leaf, find applications in automotive industries. While most of the other fibers are explored in lab scales they have not yet found large-scale commercial applications. It is necessary to also consider other fibers such as ones made from seed (coir) and animals (chicken feather) as they are secondary or made from waste products. Few plant fibers such as bast fibers are often reviewed briefly but other plant and animal fibers are not discussed in detail. This review paper discusses all the six types of plant fibers such as bast, leaf, seed, straw, grass, and wood, together with animal fibers and regenerated cellulose fibers. Additionally, the review considers developments dealing with natural fibers and their composites. The fiber source, extraction, availability, type, composition, and mechanical properties are discussed. The advantages and disadvantages of using each biofiber are discussed. Three fabric architectures such as nonwoven, woven and knitted have been briefly discussed. Finally, the paper presents the overview of the results from the composites made from each fiber with suitable references for in-depth studies.
Ioncell-F, a recently developed process for the production of man-made cellulosic fibers from ionic liquid solutions by dry-jet wet spinning, is presented as an alternative to the viscose and N-methylmorpholine N-oxide (NMMO)-based Lyocell processes. The ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene acetate was identified as excellent cellulose solvent allowing for a rapid dissolution at moderate temperatures and subsequent shaping into continuous filaments. The highly oriented cellulose fibers obtained upon coagulation in cold water exhibited superior tenacity, exceeding that of commercial viscose and NMMO-based Lyocell (Tencel®) fibers. The respective staple fibers, which have been converted into two-ply yarn by ring spinning technology, presented very high tenacity. Furthermore, the Ioncell yarn showed very good behavior during the knitting and weaving processes, reflecting the quality of the produced yarn. The successfully knitted and woven garments from the Ioncell yarn demonstrate the suitability of this particular ionic liquid for the production of man-made cellulosic fibers and thus give a promising outlook for the future of the Ioncell-F process.
SUMMARYAim: To assess the efficacy and safety of budesonide capsules 6 mg daily for prolongation of time to relapse and maintenance of remission in patients with Crohn's disease (CD) affecting the ileum and/or ascending colon. Methods: In a double-blind, placebo-controlled, multicentre trial, 110 patients with CD, who had previously achieved remission in a placebo-controlled trial of budesonide 9 mg daily, were randomly assigned to receive budesonide 6 mg once daily or placebo for 52 weeks. Primary outcome measure was time to relapse [CD activity index (CDAI) of >150 plus an increase of at least 60 points from study entry or withdrawal due to clinical deterioration]. Results: Median time to relapse was 360 days for budesonide patients; 169 days for placebo patients (P ¼ 0.132). No significant differences were seen between groups in relapse rates at 1 year. Budesonide was safe and well tolerated, with a similar adverse events profile to placebo. Conclusion: Patients treated with budesonide 6 mg once daily had a trend towards a prolonged time to relapse and lower CDAI scores compared with patients treated with placebo, but relapse rates were not significantly different at the 1-year end point.
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