Manju Kumari Thakur

Bio: Manju Kumari Thakur is an academic researcher from Himachal Pradesh University. The author has contributed to research in topics: Polymer & Cellulose. The author has an hindex of 31, co-authored 72 publications receiving 5424 citations.

Progress in Green Polymer Composites from Lignin for Multifunctional Applications: A Review

Abstract: Rising environmental concerns and depletion of petro-chemical resources has resulted in an increased interest in biorenewable polymer-based environmentally friendly materials. Among biorenewable polymers, lignin is the second most abundant and fascinating natural polymer next to cellulose. Lignin is one of the three major components found in the cell walls of natural lignocellulosic materials. Lignin is widely available as a major byproduct of a number of industries involved in retrieving the polysaccharide components of plants for industrial applications, such as in paper making, ethanol production from biomass, etc. The impressive properties of lignin, such as its high abundance, low weight, environmentally friendliness and its antioxidant, antimicrobial, and biodegradable nature, along with its CO2 neutrality and reinforcing capability, make it an ideal candidate for the development of novel polymer composite materials. Considerable efforts are now being made to effectively utilize waste lignin as one ...

Recent Advances in Graft Copolymerization and Applications of Chitosan: A Review

Abstract: Chitosan is among one of the most important and most studied natural polymers. The cationic nature of chitosan makes it a polymer of high importance from environmental and biomedical point of views among the other natural polysaccharides. However, it also suffers from a few disadvantages and requires further development to achieve the targeted results and desired range of efficiency. To overcome some of the disadvantages of the pristine chitosan, it is most imperative to functionalize it with suitable functional groups. Therefore, it is highly desired to understand the chemistry of the reactions used to alter the surface characteristics of chitosan. Among various techniques presently being used to tailor the surface characteristics of chitosan, graft copolymerization is of the utmost importance. The aim of the present perspective is to describe the recent advances in the graft copolymerization of chitosan with particular emphasis on atom transfer radical polymerization (ATRP). This perspective describes t...

Paving the Way for Lignin Valorisation: Recent Advances in Bioengineering, Biorefining and Catalysis.

Abstract: Lignin is an abundant biopolymer with a high carbon content and high aromaticity. Despite its potential as a raw material for the fuel and chemical industries, lignin remains the most poorly utilised of the lignocellulosic biopolymers. Effective valorisation of lignin requires careful fine-tuning of multiple "upstream" (i.e., lignin bioengineering, lignin isolation and "early-stage catalytic conversion of lignin") and "downstream" (i.e., lignin depolymerisation and upgrading) process stages, demanding input and understanding from a broad array of scientific disciplines. This review provides a "beginning-to-end" analysis of the recent advances reported in lignin valorisation. Particular emphasis is placed on the improved understanding of lignin's biosynthesis and structure, differences in structure and chemical bonding between native and technical lignins, emerging catalytic valorisation strategies, and the relationships between lignin structure and catalyst performance.

Bright Side of Lignin Depolymerization: Toward New Platform Chemicals

Abstract: Lignin, a major component of lignocellulose, is the largest source of aromatic building blocks on the planet and harbors great potential to serve as starting material for the production of biobased products. Despite the initial challenges associated with the robust and irregular structure of lignin, the valorization of this intriguing aromatic biopolymer has come a long way: recently, many creative strategies emerged that deliver defined products via catalytic or biocatalytic depolymerization in good yields. The purpose of this review is to provide insight into these novel approaches and the potential application of such emerging new structures for the synthesis of biobased polymers or pharmacologically active molecules. Existing strategies for functionalization or defunctionalization of lignin-based compounds are also summarized. Following the whole value chain from raw lignocellulose through depolymerization to application whenever possible, specific lignin-based compounds emerge that could be in the fu...

Progress in Green Polymer Composites from Lignin for Multifunctional Applications: A Review

Abstract: Rising environmental concerns and depletion of petro-chemical resources has resulted in an increased interest in biorenewable polymer-based environmentally friendly materials. Among biorenewable polymers, lignin is the second most abundant and fascinating natural polymer next to cellulose. Lignin is one of the three major components found in the cell walls of natural lignocellulosic materials. Lignin is widely available as a major byproduct of a number of industries involved in retrieving the polysaccharide components of plants for industrial applications, such as in paper making, ethanol production from biomass, etc. The impressive properties of lignin, such as its high abundance, low weight, environmentally friendliness and its antioxidant, antimicrobial, and biodegradable nature, along with its CO2 neutrality and reinforcing capability, make it an ideal candidate for the development of novel polymer composite materials. Considerable efforts are now being made to effectively utilize waste lignin as one ...

A Review on Natural Fiber Reinforced Polymer Composite and Its Applications

Abstract: Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs) and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs.

Strategies for the Conversion of Lignin to High-Value Polymeric Materials: Review and Perspective

Abstract: The majority of commodity plastics and materials are derived from petroleum-based chemicals, illustrating the strong dependence on products derived from non-renewable energy sources. As the most accessible, renewable form of carbon (in comparison to CO2), lignocellulosic biomass (defined as organic matter available on a renewable basis) has been acknowledged as the most logical carbon-based feedstock for a variety of materials such as biofuels and chemicals. This Review focuses on methods developed to synthesize polymers derived from lignin, monolignols, and lignin-derived chemicals. Major topics include the structure and processing of lignocellulosic biomass to lignin, polymers utilizing lignin as a macromonomer, synthesis of monomers and polymers from monolignols, and polymers from lignin-derived chemicals, such as vanillin.