Novel Biodegradable Polymer with Redox‐Triggered Backbone Cleavage Through Sequential 1,6‐Elimination and 1,5‐Cyclization Reactions

2017 ◽  
Vol 38 (19) ◽  
pp. 1700395 ◽  
Author(s):  
Chang‐Hee Whang ◽  
Kyeong Soo Kim ◽  
Jungeun Bae ◽  
Jun Chen ◽  
Ho‐Wook Jun ◽  
...  
Keyword(s):  
Biodegradable Polymer ◽  
Backbone Cleavage ◽  
Cyclization Reactions

Mechanistic Study and Development of Catalytic Reactions of Sm(II)

2018 ◽  
Author(s):  
Sandepan Maity ◽  
Robert Flowers
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Proton Donor ◽  
Catalytic Reactions ◽  
Mechanistic Study ◽  
Mechanistic Studies ◽  
Cyclization Reactions ◽  
Mechanistic Approach ◽  
Donor Source

Despite the broad utility and application of SmI<sub>2</sub>in synthesis, the reagent is used in stoichiometric amounts and has a high molecular weight, resulting in a large amount of material being used for reactions requiring one or more equivalents of electrons. We report mechanistic studies on catalytic reactions of Sm(II) employing a terminal magnesium reductant and trimethyl silyl chloride in concert with a non-coordinating proton donor source. Reactions using this approach permitted reductions with as little as 1 mol% Sm. The mechanistic approach enabled catalysis employing HMPA as a ligand, facilitating the development of catalytic Sm(II) 5-<i>exo</i>-<i>trig </i>ketyl olefin cyclization reactions.

Possibilities of using biodegradable polymeric materials in the agricultural sector

2020 ◽  
Vol 67 (2) ◽  
pp. 115-120
Author(s):  
Raisa A. Alekhina ◽  
Victoriya E. Slavkina ◽  
Yuliya A. Lopatina
Keyword(s):  
Mechanical Properties ◽  
Biodegradable Polymers ◽  
Biodegradable Polymer ◽  
Agricultural Sector ◽  
Polymeric Materials ◽  
Polymer Materials ◽  
Limiting Factors ◽  
Research Purpose ◽  
Biodegradable Materials ◽  
Advantages And Disadvantages

The article presents options for recycling polymers. The use of biodegradable materials is promising. This is a special class of polymers that can decompose under aerobic or anaerobic conditions under the action of microorganisms or enzymes forming natural products such as carbon dioxide, nitrogen, water, biomass, and inorganic salts. (Research purpose) The research purpose is in reviewing biodegradable materials that can be used for the manufacture of products used in agriculture. (Materials and methods) The study are based on open information sources containing information about biodegradable materials. Research methods are collecting, studying and comparative analysis of information. (Results and discussion) The article presents the advantages and disadvantages of biodegradable materials, mechanical properties of the main groups of biodegradable polymers. The article provides a summary list of agricultural products that can be made from biodegradable polymer materials. It was found that products from the general group are widely used in agriculture. Authors have found that products from a special group can only be made from biodegradable polymers with a controlled decomposition period in the soil, their use contributes to increasing the productivity of crops. (Conclusions) It was found that biodegradable polymer materials, along with environmental safety, have mechanical properties that allow them producing products that do not carry significant loads during operation. We have shown that the creation of responsible products (machine parts) from biodegradable polymers requires an increase in their strength properties, which is achievable by creating composites based on them. It was found that the technological complexity of their manufacture and high cost are the limiting factors for the widespread use of biodegradable polymers at this stage.

scholarly journals Insights into Biodegradable Polymer-Supported Titanium Dioxide Photocatalysts for Environmental Remediation

Macromol ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 201-233
Author(s):  
Nina Maria Ainali ◽  
Dimitrios Kalaronis ◽  
Eleni Evgenidou ◽  
Dimitrios N. Bikiaris ◽  
Dimitra A. Lambropoulou
Keyword(s):  
Titanium Dioxide ◽  
Biodegradable Polymers ◽  
Biodegradable Polymer ◽  
Environmental Remediation ◽  
Mechanical Stability ◽  
Dip Coating ◽  
Tio2 Photocatalysts ◽  
Chemical Inertness ◽  
Polymeric Substrates ◽  
Published Research

During the past two decades, immobilization of titanium dioxide (TiO2), a well-known photocatalyst, on several polymeric substrates has extensively gained ground since it limits the need of post-treatment separation stages. Taking into account the numerous substrates tested for supporting TiO2 photocatalysts, the use of biodegradable polymer seems a hopeful option owing to its considerable merits, including the flexible nature, low price, chemical inertness, mechanical stability and wide feasibility. The present review places its emphasis on recently published research articles (2011–2021) and exhibits the most innovative studies facilitating the eco-friendly biodegradable polymers to fabricate polymer-based photocatalysts, while the preparation details, photocatalytic performance and reuse of the TiO2/polymer photocatalysts is also debated. The biodegradable polymers examined herein comprise of chitosan (CS), cellulose, alginate, starch, poly(lactid acid) (PLA), polycaprolactone (PCL) and poly(lactide-co-glycolide) (PLGA), while an emphasis on the synthetical pathway (dip-coating, electrospinning, etc.) of the photocatalysts is provided.

scholarly journals Pt(II)-Decorated Covalent Organic Framework for Photocatalytic Difluoroalkylation and Oxidative Cyclization Reactions

2021 ◽  
Vol 13 (5) ◽  
pp. 6349-6358
Author(s):  
Zainab Almansaf ◽  
Jiyun Hu ◽  
Federica Zanca ◽  
Hamid R. Shahsavari ◽  
Benjamin Kampmeyer ◽  
...  
Keyword(s):  
Oxidative Cyclization ◽  
Cyclization Reactions ◽  
Covalent Organic Framework ◽  
Organic Framework
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