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Bionanocomposites, Their Processing, and Environmental Applications
Published in Shakeel Ahmed, Saiqa Ikram, Suvardhan Kanchi, Krishna Bisetty, Biocomposites, 2018
Sagar Roy, Chaudhery Mustansar Hussain
Several varieties of polycarbonates prepared from different monomers are of great interest. Trimethylene carbonate is used as the monomer during the synthesis of poly(trimethylene carbonate) (PTMC) via ring-opening polymerization technique in the presence of diethylzinc as the reaction catalyst. The polymer alone exhibits very poor mechanical properties, thus copolymerized with several other monomers, such as glycolide and dioxanone, to obtain the desired characteristics. Another variety of polycarbonate is poly(propylene carbonate) (PPC), synthesized via copolymerization of propylene oxide and carbon dioxide. The polymer enhances compatibility and impact resistance. However, biodegradability is quite poor and can be improved through blending with other suitable polymers. Introduction of other polymers may decrease crystallinity, which enhances its susceptibility to enzymatic and microbial attacks.
Degradation Studies of Biodegradable Composites
Published in Arbind Prasad, Ashwani Kumar, Kishor Kumar, Biodegradable Composites for Packaging Applications, 2023
The conversion of CO2 into polymeric polymers provides a potential greenhouse gas recycling alternative. Polypropylene carbonate (PPC) is made by copolymerizing carbon dioxide with propylene oxide. The biological breakdown of PPC is aided by high temperatures. After 6 months, a total mass loss of just 3.2% was detected in garden soil (Du, L.C et al., 2004). A mass loss of 8% was recorded at 40°C in a composting setting, followed by a significant rise in disparity (Bahramian et al., 2016). After only 3 months in an industrial composting operation (at 60°C), a full absolute mass loss may be recorded (Luinstra, 2008).
Eco-friendly based stability-indicating RP-HPLC technique for the determination of escitalopram and etizolam by employing QbD approach
Published in Green Chemistry Letters and Reviews, 2022
Durga Devi Perumal, Manikandan Krishnan, K.S. Lakshmi
High-performance liquid chromatography (HPLC) is one of the most effective and quick chromatographic techniques. HPLC machines feature more delicate columns and smaller sizes, which might be a key factor in laboratory environments (5, 6). Any soluble substance, regardless of its volatility, can be handled by HPLC. Selection of suitable eco-friendly solvents could be achieved with the help of several solvent selection guidelines proposed by different companies. Solvent selection guidelines used in various companies such as Pfizer guide, Vapourtec, Gsk, ACS GCI Pharmaceutical Roundtable (7–9). The majority of the guidelines classify solvents according to their environmental hazard safety (EHS) and net cumulative energy demand (NED) (CED). Only a few solvents that are both ecologically friendly and have low CED values are available. However, these solvents cannot be used effectively as an organic phase in drug analysis, owing to limitations such as high equipment noise and poor drug compatibility. This study concluded that ethanol is an excellent alternative to methanol and propylene carbonate, which are hazardous solvents. To make it acidic, orthophosphoric, glacial acetic, or formic acids were used. For the C18 column, the pH should be adjusted to 3–6.5, or the queue should be destroyed. It is possible to adjust the pH from 1 to 11 if an HPLC column is pH stable (10). Therefore, we conclude that ethanol is a greener solvent that can be used instead of dangerous methanol and polypropylene carbonate.
Biodegradable all-polymer field-effect transistors printed on Mater-Bi
Published in Journal of Information Display, 2021
Elena Stucchi, Ksenija Maksimovic, Laura Bertolacci, Fabrizio Antonio Viola, Athanassia Athanassiou, Mario Caironi
Next to these materials, synthetic polymers for biodegradable substrate applications have been presented in literature. The three main examples include polydimethylsiloxane, a well-known biocompatible and biodegradable polymer [52–54], polyvinyl alcohol [47,55–60], and polylactic acid [43,61]. Other synthetic polymers employed as substrates for biodegradable electronics are poly-lactic-go-glycolacid [62–64], polycaprolactone [65], poly(1,8-octanediol-co-citrate) [66], polypropylene carbonate [67], polyvinylpyrrolidone [68] and polyhydroxyalkanoates [69], poly(3-hydroxybutyrate) and its copolymer with poly(3-hydroxyvalerate) [70–72].