A novel bioresin, epoxidized soybean oil was synthesized by in situ method and was characterized employing FTIR and NMR. The bioresin was blended with epoxy (DGEBA) at different ratios as reactive diluents for improved processibility and toughened nature. The composition with 20 wt% bioresin exhibited improved impact strength to the tune of 60% as compared to virgin epoxy. Fracture toughness parameters critical stress intensity factor (K IC ) and critical strain energy release rate (G IC ) were evaluated using single edge notch bending test and demonstrated superior enhancement in toughness. Dynamic mechanical, thermal, thermo mechanical and fracture morphological analyses have been studied for bio-based epoxy blends. Curing kinetics has been evaluated through DSC analysis to investigate the effect of bioresin on cross-linking reaction of neat epoxy with triethylenetetramine as curing agent.

Novel bioresin epoxy methyl soyate was synthesized by transesterification process and subsequently used as reactive diluent for toughening of epoxy.

In the current work, renewable resourced toughened epoxy blend has been developed using epoxidized linseed oil (ELO) and bio-based crosslinker. Epoxidation of linseed oil was confirmed through FTIR and 1 H NMR spectra. The ELO bio-resin was blended at different compositions (10, 20, and 30 phr) with a petroleum-based epoxy (DGEBA) as reactive diluent to reduce the viscosity for better processibility and cured with cardanol-derived phenalkamine to overcome the brittleness. The flow behavior of the neat epoxy and modified bio-epoxy resin blend systems was analyzed by Cross model at low and high shear rates. The tensile and impact behavior studies revealed that the toughened bio-epoxy blend with 20 to 30 phr of ELO showed moderate stiffness with much higher elongation at break 7% to 13%. Incorporation of higher amount of ELO (20 to 30 phr) increases enthalpy of curing without affecting peak temperature of curing. The thermal degradation behavior of the ELO based blends exhibits similar trend as neat epoxy.The higher intensity or broadened loss tangent curve of bio-epoxy blends revealed higher damping ability. FE-SEM analysis showed a rough and rippled surface of bio-based epoxy blends ensuring effective toughening. Reduced viscosity of resin due to maximum possible incorporation of bio-resin and use of phenalkamine as curing agent leads to an eco-friendly toughened epoxy and can be useful for specific coating and structural application. KEYWORDSbio-based epoxy, epoxidized oil, phenalkamine, thermomechanical properties, toughening Functionalized vegetable oils have been reported as renewable resourced toughening diluents for epoxy to overcome its inherent brittleness. [5][6][7][8][9][10][11][12][13][14][15][16] Particularly, epoxidized oils having multiple epoxy groups are more preferable to be used as reactive diluents being eco-friendly and ease synthesis process. Soybean oil due to ease of availability, higher number of reacting sites (4.6 double bonds per triglyceride chain), and low cost has attracted attention of researchers in employing it to enhance toughness of petro-based epoxies in the last decade. However, the tensile and thermal properties of epoxy drastically reduce with increase in ESO content because of its lower reactivity, low oxirane content, and inferior crosslink density. 5-10Further, the wide use of soybean oil in thermoset and thermoplastic has been reported on ELO-based bio-epoxy blends using bio-renewable PKA as curing agent.In the current work, ELO was synthesized through in-situ method, and bio-epoxy blends were prepared with varying ELO content as reactive diluent. The diluent content can be optimized based on rheological, mechanical, and thermo-mechanical specification needed for specific structural application. | Synthesis of epoxidized linseed oilLinseed was epoxidized through in-situ method in the presence of glacial acetic acid and hydrogen peroxide as reported earlier by Kim et al 6 and Sahoo et al. 13 Epoxidation of oil was performed in a 3-necked flask equipped with a magnetic st...

Bio‐based epoxy resins were synthesized from nonedible resources like linseed oil and castor oil. Both the oils were epoxidized through in situ method and characterized via Fourier transform infrared and 1H‐NMR. These epoxidized oils were crosslinked with citric acid without using any catalyst and their properties compared with diglycidyl ether of bisphenol A‐epoxy. The tensile strength and modulus of epoxidized linseed oil (ELO) were found to be more than those of epoxidized castor oil (ECO)‐based network. However, elongation at break of ECO was significantly higher than that of both ELO and epoxy, which reveals its improved flexibility and toughened nature. Thermogravimetric analysis revealed that the thermal degradation of ELO‐based network is similar to that of petro‐based epoxy. Dynamic mechanical analysis revealed moderate storage modulus and broader loss tangent curve of bio‐based epoxies confirming superior damping properties. Bioepoxies exhibit nearly similar contact angle as epoxy and display good chemical resistant. The preparation method does not involve the use of any toxic catalyst and more hazardous solvents, thus being eco‐friendly.

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OBJECT The cause of irreducibility in irreducible atlantoaxial dislocation (AAD) appears to be the orientation of the C1–2 facets. The current management strategies for irreducible AAD are directed at removing the cause of irreducibility followed by fusion, rather than transoral decompression and posterior fusion. The technique described in this paper addresses C1–2 facet mobilization by facetectomies to aid intraoperative manipulation. METHODS Using this technique, reduction was achieved in 19 patients with congenital irreducible AAD treated between January 2011 and December 2013. The C1–2 joints were studied preoperatively, and particular attention was paid to the facet orientation. Intraoperatively, oblique C1–2 joints were opened widely, and extensive drilling of the facets was performed to make them close to flat and parallel to each other, converting an irreducible AAD to a reducible one. Anomalous vertebral arteries (VAs) were addressed appropriately. Further reduction was then achieved after vertical distraction and joint manipulation. RESULTS Adequate facet drilling was achieved in all but 2 patients, due to VA injury in 1 patient and an acute sagittal angle operated on 2 years previously in the other patient. Complete reduction could be achieved in 17 patients and partial in the remaining 2. All patients showed clinical improvement. Two patients showed partial redislocation due to graft subsidence. The fusion rates were excellent. CONCLUSIONS Comprehensive drilling of the C1–2 facets appears to be a logical and effective technique for achieving direct posterior reduction in irreducible AAD. The extensive drilling makes large surfaces raw, increasing fusion rates.

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