The present study deals with the enzymatic synthesis of biodiesel by transesterification of Jatropha oil (Jatropha curcas L.) with ethanol in a solvent-free system. Seven commercial lipase preparations immobilized by covalent attachment on epoxy-polysiloxane-polyvinyl alcohol composite (epoxy-SiO2-PVA) were tested as biocatalysts. Among them, immobilized lipases from Pseudomonas fluorescens (li...

1. The activity of chicken pepsin was partially inhibited by dimethyl-(2-hydroxy-5-nitrobenzyl)sulphonium bromide, but was unaffected by p-bromophenacyl bromide. 2. In the presence of Cu2+, diazoacetylnorleucine methyl ester completely inactivated chicken pepsin with the incorporation of 1 mol/mol. The mechanism of the reaction was similar to that with pig pepsin. 3. Chicken pepsin was complete...

In the present work, an attempt has been made to develop high-performance polymeric hybrid binary blends of epoxy/benzoxazine and benzoxazine/cyanate ester with varying weight percentages (25/75, 50/50 75/25 wt%) resins, namely, bisphenol-F epoxy resin (DGEBF), benzoxazines [bisphenol–F/aniline (BF-a) imidazole core-based bisphenol/aniline (IBP-a)] cyanate [bisphenol-F bifunctional (BF-CE)]. Th...

Bio-based alternatives for petroleum-based epoxy resin curing agents, such as maleopimaric acid (MPA), are indispensable sustainable fiber reinforced polymer composites with thermosetting matrices. However, previous investigations disregarded the importance of choosing right stoichiometric ratio R between anhydride groups in rosin-based agent and resin. Therefore, influence on kinetics mechanic...

Over a billion microwave ovens are used every day thus witnessing the importance of microwave heating in the world today. Microwave processing of polymers is a comparatively recent and vastly expanding field in industry due to economical advantages through energy saving and accelerated manufacture. Factors that hinder the use of microwaves in materials processing are decreasing every day. Epoxy...

deprotection of phosphate, phosphate, and sulfite esters by silica chloride is described. silica chloride is a mild, selective, and effective reagent for cleavage of benzyl and t-butyl esters of the above compounds.

The mechanical strength of conventional epoxy resins drops dramatically after irradiation to a fast neutron fluence of 1x10 m (E>0.1 MeV). Recent results demonstrated that cyanate ester / epoxy blends were not affected at this fluence level. The aim of this study is to investigate the performance potential of these blends at higher fluence levels without significant degradation of their mechani...