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Rationale: Small molecule inhibitors of the acetyl-histone binding protein BRD4 have been shown to block cardiac fibrosis in preclinical models of heart failure (HF). However, since the inhibitors target BRD4 ubiquitously, it is unclear whether this chromatin reader protein functions in cell type-specific manner to control pathological myocardial fibrosis. Furthermore, the molecular mechanisms by which BRD4 stimulates the transcriptional program for cardiac fibrosis remain unknown. Objective: We sought to test the hypothesis that BRD4 functions in a cell-autonomous and signal-responsive manner to control activation of cardiac fibroblasts, which are the major extracellular matrix-producing cells of the heart. Methods and Results: RNA-sequencing, mass spectrometry, and cell-based assays employing primary adult rat ventricular fibroblasts demonstrated that BRD4 functions as an effector of TGF-β (transforming growth factor-β) signaling to stimulate conversion of quiescent cardiac fibroblasts into Periostin ( Postn )-positive cells that express high levels of extracellular matrix. These findings were confirmed in vivo through whole-transcriptome analysis of cardiac fibroblasts from mice subjected to transverse aortic constriction and treated with the small molecule BRD4 inhibitor, JQ1. Chromatin immunoprecipitation-sequencing revealed that BRD4 undergoes stimulus-dependent, genome-wide redistribution in cardiac fibroblasts, becoming enriched on a subset of enhancers and super-enhancers, and leading to RNA polymerase II activation and expression of downstream target genes. Employing the Sertad4 (SERTA domain-containing protein 4) locus as a prototype, we demonstrate that dynamic chromatin targeting of BRD4 is controlled, in part, by p38 MAPK (mitogen-activated protein kinase) and provide evidence of a critical function for Sertad4 in TGF-β-mediated cardiac fibroblast activation. Conclusions: These findings define BRD4 as a central regulator of the pro-fibrotic cardiac fibroblast phenotype, establish a p38-dependent signaling circuit for epigenetic reprogramming in heart failure, and uncover a novel role for Sertad4 . The work provides a mechanistic foundation for the development of BRD4 inhibitors as targeted anti-fibrotic therapies for the heart.

Funder: FP7 Ideas: European Research Council; doi: http://dx.doi.org/10.13039/100011199; Grant(s): FP7-HEALTH-603016, FP7/2007-2013, Background: The inability to observe relevant biological processes in vivo significantly restricts human neurodevelopmental research. Advances in appropriate in vitro model systems, including patient-specific human brain organoids and human cortical spheroids (hCSs), offer a pragmatic solution to this issue. In particular, hCSs are an accessible method for generating homogenous organoids of dorsal telencephalic fate, which recapitulate key aspects of human corticogenesis, including the formation of neural rosettes—in vitro correlates of the neural tube. These neurogenic niches give rise to neural progenitors that subsequently differentiate into neurons. Studies differentiating induced pluripotent stem cells (hiPSCs) in 2D have linked atypical formation of neural rosettes with neurodevelopmental disorders such as autism spectrum conditions. Thus far, however, conventional methods of tissue preparation in this field limit the ability to image these structures in three-dimensions within intact hCS or other 3D preparations. To overcome this limitation, we have sought to optimise a methodological approach to process hCSs to maximise the utility of a novel Airy-beam light sheet microscope (ALSM) to acquire high resolution volumetric images of internal structures within hCS representative of early developmental time points. Results: Conventional approaches to imaging hCS by confocal microscopy were limited in their ability to image effectively into intact spheroids. Conversely, volumetric acquisition by ALSM offered superior imaging through intact, non-clarified, in vitro tissues, in both speed and resolution when compared to conventional confocal imaging systems. Furthermore, optimised immunohistochemistry and optical clearing of hCSs afforded improved imaging at depth. This permitted visualization of the morphology of the inner lumen of neural rosettes. Conclusion: We present an optimized methodology that takes advantage of an ALSM system that can rapidly image intact 3D brain organoids at high resolution while retaining a large field of view. This imaging modality can be applied to both non-cleared and cleared in vitro human brain spheroids derived from hiPSCs for precise examination of their internal 3D structures. This process represents a rapid, highly efficient method to examine and quantify in 3D the formation of key structures required for the coordination of neurodevelopmental processes in both health and disease states. We posit that this approach would facilitate investigation of human neurodevelopmental processes in vitro.

Neural progestin receptors (PR) function in reproduction, neural development, neuroprotection, learning, memory and the anxiety response. In the absence of progestins, PR can be activated by dopamine (DA) in the rodent hypothalamus to elicit female sexual behaviour. The present study investigated mechanisms of DA activation of PR by testing the hypothesis that proteins from DA-treated hypothalami interact with PR in the absence of progestins. Ovariectomised, oestradiol-primed mice were infused with a D1-receptor agonist, SKF38393 (SKF), into the third ventricle 30 minutes prior to death. Proteins from SKF-treated hypothalami were pulled-down with glutathione S-transferase-tagged mouse PR-A or PR-B and the interactomes were analysed by mass spectrometry. The largest functional group to interact with PR-A in a DA-dependent manner was synaptic proteins. To test the hypothesis that DA activation of PR regulates synaptic proteins, we developed oestradiol-induced PR-expressing hypothalamic-like neurones derived from human-induced pluripotent stem cells (hiPSCs). Similar to progesterone (P4), SKF treatment of hiPSCs increased synapsin1/2 expression. This SKF-dependent effect was blocked by the PR antagonist RU486, suggesting that PR are necessary for this DA-induced increase. The second largest DA-dependent PR-A protein interactome comprised metabolic regulators involved in glucose metabolism, lipid synthesis and mitochondrial energy production. Interestingly, hypothalamic proteins interacted with PR-A, but not PR-B, in an SKF-dependent manner, suggesting that DA promotes the interaction of multiple hypothalamic proteins with PR-A. These in vivo and in vitro results indicate novel mechanisms by which DA can differentially activate PR isoforms in the absence of P4 and provide a better understanding of ligand-independent PR activation in reproductive, metabolic and mental health disorders in women.

The low-density lipoprotein receptor (LDLR) controls cellular delivery of cholesterol and clears LDL from the bloodstream, protecting against atherosclerotic heart disease, the leading cause of death in the United States. We therefore sought to identify regulators of the LDLR beyond the targets of current clinical therapies and known causes of familial hypercholesterolemia. We show that Cold Shock Domain-Containing Protein E1 (CSDE1) enhances hepatic LDLR mRNA decay via its 3’ untranslated region to regulate atherogenic lipoproteins in vivo. Using parallel phenotypic genome-wide CRISPR interference screens, we found 40 specific regulators of the LDLR left unidentified by observational human genetics. Among these, we show that CSDE1 regulates the LDLR at least as strongly as the mechanistically distinct pathways exploited by the best available clinical therapies: statins and PCSK9 inhibitors. Additionally, we show that hepatic gene silencing of Csde1 treats diet-induced dyslipidemia in mice better than that of Pcsk9. Our results reveal the therapeutic potential of manipulating a newly identified key factor in the post-transcriptional regulation of the LDLR mRNA for the prevention of cardiovascular disease. We anticipate that our approach of modelling a clinically relevant phenotype in a forward genetic screen, followed by mechanistic pharmacologic dissection and in vivo validation, will serve as a generalizable template for the identification of therapeutic targets in other human disease states.One Sentence SummaryA genome-wide CRISPR screen identifies CSDE1 as a key regulator of hepatic LDLR mRNA decay in vivo, making it a promising target for heart disease.Graphical Abstract

In diseased organs, stress-activated signalling cascades alter chromatin, thereby triggering maladaptive cell state transitions. Fibroblast activation is a common stress response in tissues that worsens lung, liver, kidney and heart disease, yet its mechanistic basis remains unclear1,2. Pharmacological inhibition of bromodomain and extra-terminal domain (BET) proteins alleviates cardiac dysfunction3–7, providing a tool to interrogate and modulate cardiac cell states as a potential therapeutic approach. Here we use single-cell epigenomic analyses of hearts dynamically exposed to BET inhibitors to reveal a reversible transcriptional switch that underlies the activation of fibroblasts. Resident cardiac fibroblasts demonstrated robust toggling between the quiescent and activated state in a manner directly correlating with BET inhibitor exposure and cardiac function. Single-cell chromatin accessibility revealed previously undescribed DNA elements, the accessibility of which dynamically correlated with cardiac performance. Among the most dynamic elements was an enhancer that regulated the transcription factor MEOX1, which was specifically expressed in activated fibroblasts, occupied putative regulatory elements of a broad fibrotic gene program and was required for TGFβ-induced fibroblast activation. Selective CRISPR inhibition of the single most dynamic cis-element within the enhancer blocked TGFβ-induced Meox1 activation. We identify MEOX1 as a central regulator of fibroblast activation associated with cardiac dysfunction and demonstrate its upregulation after activation of human lung, liver and kidney fibroblasts. The plasticity and specificity of BET-dependent regulation of MEOX1 in tissue fibroblasts provide previously unknown trans- and cis-targets for treating fibrotic disease. BET proteins regulate a reversible transcriptional switch that governs fibroblast activation in heart disease through the transcription factor MEOX1.

This chapter explores our recent advances in our understanding of how estrogens can modulate spinogenesis within the cortex and its relevance for estrogenic-regulation of cognition. It describes how estrogens, including 17β‎-estradiol and estrogen receptor modulators, rapidly modify dendritic spine density concurrently with influencing cognitive behaviors that require cortical processing. Furthermore, it reviews the evidence that these effects are not limited to female animals but may represent a relevant mechanism in the male brain. This chapter will also explore the emerging role for a novel estrogen receptor, G-protein estrogen receptor (GPER), in mediating the rapid effects of estrogens on dendritic spines. Finally, the chapter also reviews the potential molecular mechanisms that underlie rapid estrogenic signaling, linking this signaling to the modulation of spinogenesis, which may ultimately provide a cellular model by which estrogens can produce long-lasting changes in neural circuitry.

Butyric acid is a monocarboxylic acid which can be produced economically by fermentation from green feedstock. As the recovery of butyric acid from dilute fermentation broth is a challenge and hence it needs to develop a competitive downstream recovery process. Butyric acid finds a wide range of applications in pharmaceutical, food, cosmetics and power industries. Reactive extraction is one of the most promising and accessible methods which can be used as first separation step for recovery of butyric acid from dilute wastewater stream or fermentation broth. In present study, the physical and reactive extraction of butyric acid using tri-n-octylamine (TOA) in biodiesel made from sesame oil, rice bran oil, karanja oil and sunflower oil were studied at 298K and comparatively found the reactive extraction as more efficient. The Partition coefficient P, dimerization constant D and the distribution coefficient KD were obtained in the physical extraction study. In reactive extraction, the results were obtained in terms of distribution coefficient KD, loading ratio O and the degree of extraction E%.

Thermogravimetric Analysis (TGA) is concluding expanding applicability in determination of the thermal stability and degradation nature of materials. The present study investigates the thermal degradation behavior and the kinetics of degradation of epoxy mixed with varying percentages of 0, 2.5, 5, and 7.5 ​wt% fly ash. Thermal stability and degradation behavior of fly ash modified epoxy cast were determined by thermogravimetric analysis. The kinetic parameters of the EF composites were calculated by using Coats–Redfern, Broido and Horowitz–Metzger models under best-fit analysis and further proved by linear regression analysis. The kinetics of thermal degradation was calculated from data scanned at a heating rate of 10 ​°C/min. The obtained results reveal that kinetic parameters and thermal behavior of EF composites were improved with the reinforcement of fly ash. The cure kinetics of the varying content of fly ash reinforced epoxy cast were also studied by using a nonisothermal differential scanning calorimetric (DSC) technique at four different heating rates 5 ​°C/min, 10 ​°C/min, 15 ​°C/min and 20 ​°C/min. The curing kinetics of the EF composite was derived from the nonisothermal differential scanning calorimetry (DSC) data with the three Kissinger, Ozawa, and Flynn–Wall–Ozawa models, respectively.

Rationale: During each beat, cardiac myocytes (CMs) generate the mechanical output necessary for heart function through contractile mechanisms that involve shortening of sarcomeres along myofibrils. Human-induced pluripotent stem cells (hiPSCs) can be differentiated into CMs (hiPSC-CMs) that model cardiac contractile mechanical output more robustly when micropatterned into physiological shapes. Quantifying the mechanical output of these cells enables us to assay cardiac activity in a dish. Objective: We sought to develop a computational platform that integrates analytic approaches to quantify the mechanical output of single micropatterned hiPSC-CMs from microscopy videos. Methods and Results: We micropatterned single hiPSC-CMs on deformable polyacrylamide substrates containing fluorescent microbeads. We acquired videos of single beating cells, of microbead displacement during contractions, and of fluorescently labeled myofibrils. These videos were independently analyzed to obtain parameters that capture the mechanical output of the imaged single cells. We also developed novel methods to quantify sarcomere length from videos of moving myofibrils and to analyze loss of synchronicity of beating in cells with contractile defects. We tested this computational platform by detecting variations in mechanical output induced by drugs and in cells expressing low levels of myosin-binding protein C. Conclusions: Our method can measure the cardiac function of single micropatterned hiPSC-CMs and determine contractile parameters that can be used to elucidate mechanisms that underlie variations in CM function. This platform will be amenable to future studies of the effects of mutations and drugs on cardiac function.

Organogenesis involves integration of myriad cell types with reciprocal interactions, each progressing through successive stages of lineage specification and differentiation. Establishment of unique gene networks within each cell dictates fate determination, and mutations of transcription factors that drive such networks can result in birth defects. Congenital heart defects are the most common malformations and are caused by disruption of discrete subsets of progenitors1–3, however, determining the transcriptional changes in individual cells that lead to organ-level defects in the heart, or other organs, has not been tractable. Here, we employed single-cell RNA sequencing to interrogate early cardiac progenitor cells as they become specified during normal and abnormal cardiogenesis, revealing how dysregulation of specific cellular sub-populations can have catastrophic consequences. A network-based computational method for single-cell RNA-sequencing that predicts lineage specifying transcription factors4,5identifiedHand2as a specifier of outflow tract cells but not right ventricular cells, despite failure of right ventricular formation inHand2-null mice6. Temporal single-cell transcriptome analysis ofHand2-null embryos revealed failure of outflow tract myocardium specification, whereas right ventricular myocardium differentiated but failed to migrate into the anterior pole of the developing heart. Dysregulation of retinoic acid signaling, responsible for anterior-posterior patterning7, was associated with posteriorization of anterior cardiac progenitors inHand2-null mutant hearts and ectopic atrial gene expression in outflow tract and right ventricle precursors. This work reveals transcriptional determinants in individual cells that specify cardiac progenitor cell fate and differentiation and exposes mechanisms of disrupted cardiac development at single-cell resolution, providing a framework to investigate congenital heart defects.

Estrogens have been shown to rapidly regulate local signalling events at both synapses and within the nucleus. The result of these signalling events is to rapidly modulate synapse structure and function, as well as epigenetic mechanisms including histone modifications. Ultimately these mechanisms are thought to contribute to long-lasting changes in neural circuitry, and thus influences cognitive functions such as learning and memory. However, the mechanisms by which estrogen-mediated local synaptic and nuclear signalling events are coordinated are not well understood. In this study we have found that the scaffold protein afadin, (also known as AF-6), undergoes a bi-directional trafficking to both synaptic and nuclear compartment in response to acute 17β-estradiol (estradiol) treatment. Interestingly, nuclear accumulation of afadin was coincidental with an increase in the phosphorylation of histone H3 at serine 10 (H3S10p). This histone modification is associated with the remodelling of chromatin into an open euchromatin state, allowing for transcriptional activation and related learning and memory processes. Critically, the cyto-nuclear trafficking of afadin was required for estradiol-dependent H3S10p. We further determined that nuclear accumulation of afadin is sufficient to induce phosphorylation of the mitogentic kinases ERK1/2 (pERK1/2) within the nucleus. Moreover, nuclear pERK1/2 was required for estradiol-dependent H3S10p. Taken together, we propose a model whereby estradiol incudes the bi-directional trafficking of afadin to synaptic and nuclear sub-compartments. Within the nucleus, afadin is required for increased pERK1/2 which in turn is required for H3S10p. Therefore this represents a mechanism through which estrogens may be able to coordinate both synaptic and nucleosomal events within the same neuronal population.

Single cardiomyocytes contain myofibrils that harbor the sarcomere-based contractile machinery of the myocardium. Cardiomyocytes differentiated from human pluripotent stem cells (hPSC-CMs) have potential as an in vitro model of heart activity. However, their fetal-like misalignment of myofibrils limits their usefulness for modeling contractile activity. We analyzed the effects of cell shape and substrate stiffness on the shortening and movement of labeled sarcomeres and the translation of sarcomere activity to mechanical output (contractility) in live engineered hPSC-CMs. Single hPSC-CMs were cultured on polyacrylamide substrates of physiological stiffness (10 kPa), and Matrigel micropatterns were used to generate physiological shapes (2,000-µm(2) rectangles with length:width aspect ratios of 5:1-7:1) and a mature alignment of myofibrils. Translation of sarcomere shortening to mechanical output was highest in 7:1 hPSC-CMs. Increased substrate stiffness and applied overstretch induced myofibril defects in 7:1 hPSC-CMs and decreased mechanical output. Inhibitors of nonmuscle myosin activity repressed the assembly of myofibrils, showing that subcellular tension drives the improved contractile activity in these engineered hPSC-CMs. Other factors associated with improved contractility were axially directed calcium flow, systematic mitochondrial distribution, more mature electrophysiology, and evidence of transverse-tubule formation. These findings support the potential of these engineered hPSC-CMs as powerful models for studying myocardial contractility at the cellular level.

The present research work focuses on the mechanical, chemical, and curing characteristics of novolac resin based on renewable resource materials such as cardanol and furfural. Cardanol, a metasubstituted phenol, is a renewable organic resource obtained as a byproduct of the cashew industry. Furfural, an aromatic aldehyde, is also a renewable resource obtained as an agricultural waste product. Novolac resin has been synthesized by the condensation of cardanol with furfural in the presence of an oxalic acid catalyst and using varied molar proportions of the reacting monomers. The reaction was performed at 120°C. The progress of the reaction was monitored by determining the free formaldehyde and free phenol content. The prepared cardanol–furfural-based novolac resins were further characterized by various techniques such as infrared and nuclear magnetic resonance spectroscopic analysis. The resins were cured using the most suitable agent, hexamethylenetetramine. The differential scanning calorimetric technique was used to investigate the curing behavior of the prepared samples. The cured film samples were used for the determination of mechanical properties such as adhesion, flexibility, scratch hardness, gloss, and impact resistance; these cured film samples were also used to observe the effect of various chemicals and solvents (chemical resistance properties) such as sulfuric acid, acetic acid, sodium hydroxide, sodium carbonate and methanol, methyl ethyl ketone, xylene, and deionized water, respectively, on the surface of the film. The resulting coatings based on prepared cardanol–furfural resin were found to have excellent mechanical and chemical resistance properties.

Cardanol-based vinyl ester resin ( CVER ) was blended with varying concentrations of Carboxyl terminated butadiene acrylonitrile (CTBN) ranging between 0 and 15 wt% with an interval increment of 5 wt%, by two different approaches, viz., physical and chemical blending. The formation of various products during the curing of blend samples has been studied by FTIR spectroscopic analysis. The dynamic DSC scans showed that the blend samples of CVERs cured in the temperature range of 100–150 °C. It was observed that the blend sample containing 5 wt% and 10 wt% liquid rubber, for physical and chemical blending, respectively, showed least cure time, at 120 °C, amongst all other blend samples. On evaluation, it was found that in toughened samples thermal and mechanical properties were marginally affected with the increase of CTBN concentration. The blend morphology, studied by scanning electron microscopy analysis, showed the presence of precipitated discrete rubber particles which dispersed throughout the vinyl ester matrix, i.e., they revealed the presence of two phase morphology.

Cardanol-based vinyl ester resin (CVER) was prepared by reacting indigenously synthesized cardanol-based epoxidized novolac resin (CENR) with methacrylic acid (MA) in the presence of triphenylphosphine as catalyst. Five samples of cardanol-based vinyl ester resin containing styrene and glycidyl methacrylate (GMA), as diluents, in the weight ratios 40:0, 30:10, 20:20, 10:30 and 0:40 were prepared at room temperature. Sharp exotherms were observed in DSC scans in the temperature range of 60–170 °C. The onset temperature ( T onset ), peak exothermic temperature ( T p ) and completion temperature ( T stop ) decreased with increase in GMA content in the ternary blend systems of CVER/styrene/GMA. A broad exotherm was observed after the initial sharp exotherm that was attributed to the etherification reaction. Cured samples were found to be stable up to 205–235 °C and started loosing weight above this temperature. Rapid decomposition was observed in the temperature range of 400–550 °C as evidenced by TGA analysis. Increase of GMA content in ternary blend systems of CVER/styrene/GMA lowered the tensile strength progressively and enhanced the impact strength and elongation-at-break. The cured films of VER containing mixture of styrene and GMA exhibited good gloss and impact resistance. The chemical resistance of cured films of VER containing mixture of styrene and GMA showed good resistance to acids, deionized water, synthetic sea water and mineral turpentine oil.

The present paper reports the preparation and thermo-mechanical characterization of epoxy resin from renewable resource materials viz. cardanol and furfural. The cardanol furfural based epoxy resin was prepared by reacting cardanol furfural based novolac resin with molar excess of epichlorohydrin, in basic medium, at 120 °C. The cardanol furfural based novolac resin was synthesized by reacting cardanol and furfural in the molar ratios viz. 1.0:0.5, 1.0:0.6, 1.0:0.7 and 1.0:0.8, respectively, using succinic acid as catalyst. The prepared resin samples were characterized by Fourier-transform infrared and nuclear magnetic resonance spectroscopic analysis. The prepared epoxy resin samples were cured by using diaminodiphenylmethane. The samples were cured at 160 °C, in an air oven, which was determined by peak temperatures from the dynamic differential scanning calorimetric (DSC) scans. DSC technique was used to investigate the curing behavior. Thermal stability, as assesed by dynamic thermogravimetric traces of the epoxy resin sample with molar ratio 1:0.8, was found to be the highest among all other samples. The castings of the cured samples were used for the determination of mechanical properties such as tensile strength, impact strength etc. whereas cured film samples were used to observe the effect of various chemicals and solvents on the surface of the film. The epoxy resin sample prepared from high molar ratio i.e. 1:0.8 was found to exhibit better mechanical and chemical properties than other samples.

Resoles were prepared under microwave irradiation with different phenols, such as phenol, o-, p-, and m-cresols, separately with formaldehyde having formaldehyde/phenol ratio of 2:1 in basic medium. Analogical synthesis was performed using conventional heating for comparing the methods. The methylolation of phenol was confirmed by Fourier transform infrared spectroscopic analysis and a reaction mechanism was proposed. The number-average molecular weight was found by gel permeation chromatography technique. On the basis of the calculated value of kinetic chain length, the structure of the resole-type phenolic resin was proposed. Differential scanning calorimetry technique was used to investigate the curing behavior. As assessed by dynamic thermogravimetry, traces of resole sample prepared from p-cresol were found to possess better thermal stability, both in conventional as well as microwave-irradiated systems, among all other resole samples. The tensile strength, elongation at break, and impact strength showed an increasing trend. The main advantage of the process is about sixfold reduction of reaction time of the process carried at microwave reactors in comparison with the conventional heating.

The esterification reaction of phenol-cardanol based epoxidized novolac-vinyl ester resins was performed in the temperature range of 80–120 °C with an interval of 10 °C using a 1:0.9, epoxy-to-carboxylic group ratio in the presence of triphenyl phosphine as catalyst. The results based on kinetic study, indicated that the reaction followed first order kinetics. FT-IR analysis of vinyl ester resins revealed that addition esterification reaction between carbonyl and epoxy group took place and no side chain reactions occurred during the synthesis. A comparison of mechanism based rate equation and experimental data showed an excellent agreement. Finally, Arrhenius equation and activation energy were presented. The specific rate constants, based on linear regression analysis, were found to obey Arrhenius equation. The values of activation energy, frequency factor, enthalpy, entropy, and free energy of the reaction revealed that the reaction was spontaneous and irreversible and produced a highly activated complex.

Cashew nut shell liquid (CNSL), an agricultural renewable resource material, produces natural phenolic distillates such as cardanol. Cardanol condenses with formaldehyde at the ortho- and para-position of the phenolic ring under acidic or alkaline condition to yield a series of polymers of novolac- or resol-type phenolic resins. These phenolic resins may further be modified by epoxidation with epichlorohydrin to duplicate the performance of such phenolic-type novolacs (CFN). The structural changes during curing of blend samples of epoxy and carboxyl terminated poly (butadiene-co-acrylonitrile) (CTBN) were studies by Fourier-transform infrared (FTIR) spectrophotometer. The epoxy samples were synthesized by biomass material, cardanol. Blend sample was prepared by physical mixing of CTBN ranging between 0 and 20 weight percent CTBN liquid rubber into cardanol-based epoxidized novolac (CEN) resin. The FTIR spectrum of uncured blend sample clearly indicated that there appeared a band in the region of 3200–3500 cm− 1 which might be due to the presence of phenolic hydroxyl group and OH group of the opened epoxide. Pure epoxy resin showed peaks near 856 cm− 1 which might be due to oxirane functionality of the epoxidized novolac resin. Both epoxy and its blend sample was cured with polyamine. The cure temperature of CEN resin was found to be decreased by the incorporation of CTBN. The decomposition behavior was also studied by thermogravimetric analyzer (TGA). Two-step decomposition behavior was observed in both epoxy and its blend samples.

Epoxidized cardanol/formaldehyde resins (ERCF) were synthesized by reacting resole type cardanol/formaldehyde resin and epichlorohydrin in basic medium at 120 °C. Resole-type phenolic resins were synthesized by reacting cardanol and formaldehyde (molar ratios 1:1.3, 1:1.5, 1:1.7, 1:1.9,and 1:2.1) in the presence of sodium hydroxide, as catalyst, at five different temperatures ranging between 60 and 80 °C with an interval of 5°C for a maximum period of 6 h. A set of samples were characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopic analysis. The molecular size distribution of resole phenolics was studied by high-resolution gel permeation chromatography. Differential scanning calorimetry technique was used to investigate the curing behavior of the synthesized epoxy resins. Single-step mass loss in dynamic thermo gravimetric traces for the ERCF was observed.

Rationale: Formation and remodeling of the vasculature during development and disease involve a highly conserved and precisely regulated network of attractants and repellants. Various signaling pathways control the behavior of endothelial cells, but their posttranscriptional dose titration by microRNAs is poorly understood. Objective: To identify microRNAs that regulate angiogenesis. Methods and Results: We show that the highly conserved microRNA family encoding miR-10 regulates the behavior of endothelial cells during angiogenesis by positively titrating proangiogenic signaling. Knockdown of miR-10 led to premature truncation of intersegmental vessel growth in the trunk of zebrafish larvae, whereas overexpression of miR-10 promoted angiogenic behavior in zebrafish and cultured human umbilical venous endothelial cells. We found that miR-10 functions, in part, by directly regulating the level of fms-related tyrosine kinase 1 (FLT1), a cell-surface protein that sequesters vascular endothelial growth factor, and its soluble splice variant sFLT1. The increase in FLT1/sFLT1 protein levels upon miR-10 knockdown in zebrafish and in human umbilical venous endothelial cells inhibited the angiogenic behavior of endothelial cells largely by antagonizing vascular endothelial growth factor receptor 2 signaling. Conclusions: Our study provides insights into how FLT1 and vascular endothelial growth factor receptor 2 signaling is titrated in a microRNA-mediated manner and establishes miR-10 as a potential new target for the selective modulation of angiogenesis.

The cure kinetics of vinyl ester–styrene system was studied by non-isothermal differential scanning calorimetric (DSC) technique at four different heating rates. The kinetic parameters of the curing process were determined by isoconversional method for the kinetic analysis of the data obtained by the thermal treatment. Activation energy (Ea = 56.63 kJ mol−1) was evaluated for the cure process and a two-parameter (m, n) autocatalytic model was found to be the most adequate to describe the cure kinetics of the studied cardanol-based vinyl ester resin. Non-isothermal DSC curves, as obtained by using the experimental data, show good agreement with the DSC curves obtained by theoretically calculated data.

Cardanol-based epoxidized resole resins (ERCF) were synthesized by reacting resole type phenolic resin (RCF) and epichlorohydrin in basic medium, at 120 °C. Resole type phenolic resins were synthesized by reacting cardanol (C) and formaldehyde (F) in the presence of sodium hydroxide, as catalyst, at five different temperatures ranging between 60-80 °C with an interval of 5 °C for a maximum period of 6h. These prepared samples were cured using 15% polyamide as curing agent at 120 ± 2 °C for 1h. Mechanical and chemical resistance characteristics of prepared samples were evaluated to assess the possibility of using such thermosetting resins as a new eco-friendly material for engineering applications. Upon evaluation, it was found that the prepared resins systems exhibit better properties compared to commercial epoxy resin in term of increase in tensile strength, elongation-at-break and impact strength, of castings and gloss, scratch hardness, adhesion and flexibility of the films. The anticorrosive properties from chemical resistance of the prepared resin systems are found to be superior than unmodified epoxy resins. The TG/DTG thermograms showed two step decomposition behaviors in all the prepared samples.

Diglycidyl ether of bisphenol—A (DGEBA)—based epoxy resin was blended in the ratio of 3:1 (weight basis) with cycloaliphatic epoxy (CAE) resin. The prepared blend sample was further blended with different weight percentages of carboxyl-terminated butadiene acrylonitrile copolymer (CTBN) ranging between 0 and 25 wt% with an interval of 5 wt% and cured with stiochiometric amounts of 4, 4’- diamino diphenyl sulphone (DDS) cure agent. Structural changes during blending were studied by Fourier-transform infra-red (FTIR) spectroscopic analysis. The kinetic parameters, viz., order of decomposition reaction (n), activation energy (E), pre-exponential factor (Z) and rate decomposition constant (k), for the decomposition of the samples were calculated by applying Coats-Redfern equation over thermogravimetric (TG) data. The degradation of each sample followed second-order degradation kinetics, which was calculated by Coats-Redfern equation using best-fit analysis. This was further confirmed by linear regression analysis. The validity of data was checked by t-test statistical analysis. Further, the blend sample had higher initial degradation temperature and activation energy than its respective pure epoxy resin indicating that the CTBN acted as thermal stabilizer for epoxy resin which improved the thermal stability.

The effect of fullerene (C60 ) on the radical polymerization of methyl acrylate (MA), in dioxane, was studied kinetically, where triphenyl bismuthonium 1,2,3,4 tetra phenyl cyclopentadiene ylide and ylide-mercuric chloride {ylide-HgCl2} complex were used as initiators. Rp, at low fullerene concentration, may be expressed as Rp ∝ [Ylide]0.5 [MA]1.0 [Full]−0.5 on the basis of the results at 60°C. The {ylide-HgCl2} complex has been found to be more efficient initiator than ylide for the polymerization. The polymer has been characterized by FTIR, 1H-NMR and 13C-NMR spectroscopic analysis. A mechanism for polymerization, involving the reactions of free radical produced by decomposition of ylide or ylide-complex (initiator) with MA and C60 in initiation steps, has been proposed. Fullerene competes with MA for free radicals and acts as a free radical inhibitor that can also be incorporated into the final polymer to produce fullerene terminated polymeric structures.

The degradation of the epoxy system was studied for the prepared six blend samples with the incorporation of 0 wt% - 25 wt% carboxyl terminated butadiene acrylonitrile (CTBN) copolymer, on a dynamic basis using Thermo gravimetric analysis (TGA) technique under a nitrogen atmosphere. The blends were prepared by physical mixing and were cured with diamine. The degradation of each sample followed second-order degradation kinetics, which was calculated by Coats-Redfern equation using best-fit analysis. This was further confirmed by linear regression analysis. The validity of data was checked by t-test statistical analysis. From this value of reaction order, activation energy (E), and pre-exponential factor (Z) were calculated. It was found that the activation energy increased with the addition of liquid elastomer.

Cardanol-based epoxidized novolac vinyl ester resin (CNEVER) was synthesized by reacting cardanol-based epoxidized novolac (CNE) resin and methacrylic acid (MA) (CNE:MA molar ratio 1:0.9) in presence of triphenylphosphine as catalyst at 90 °C. The CNE resin was prepared by the reaction of cardanol-based novolac-type phenolic (CFN) resin and epichlorohydrin, in basic medium, at 120 °C. The CFN resin was synthesized by reacting cardanol (C) and formaldehyde (F) (C/F ratio = 1:0.7) with p -toluene sulphonic acid (PTSA) as catalyst (0.5 wt.%) at 120 °C for 7 h. The resin products were analyzed by Fourier-transform infra-red (FTIR) and nuclear magnetic resonance (NMR) spectroscopic analysis. The number-average molecular weight of the prepared CNEVER was found to be 859 gmol −1 as determined by gel permeation chromatographic (GPC) analysis. The resin was cured by using the mixture of resin, benzoyl peroxide, and styrene at 120 °C. The CNEVER resin was found to be cured in 60 min at 120 °C. Differential scanning calorimetric (DSC) technique was used to investigate the curing behaviour. Single step mass loss in dynamic thermogravimetric (TG) trace of CNEVER was observed. Thermal stability of the vinyl ester sample containing 40 wt.% styrene was the highest amongst all other prepared systems.

The effects of variation of styrene content on the thermal, mechanical and morphological behaviours of epoxy novolac vinyl ester resin (EVER)/glass fabric laminate have been investigated. The vinyl ester resin matrix was synthesized indigenously using epoxy novolac resin and methacrylic acid catalyzed by triphenylphosphine at a temperature of 85 °C in nitrogen atmosphere. Fourier-transform infra-red spectroscopic (FT-IR) analysis was used to see the structural changes during the synthesis of the EVER. Differential scanning calorimetric (DSC) technique was used to investigate the curing behaviour of the EVER matrix. Exothermic peaks (Tp) appeared in the range of 117–127 °C for all the samples of epoxy resin and EVERs. Thermal stability of the prepared samples was analyzed by dynamic thermogravimetric runs. The TG/DTG trace of epoxy showed two-step mass loss decomposition behaviour whereas that of vinyl ester resin exhibited a single step mass loss. Mechanical properties such as tensile, flexural and impact strengths of the prepared laminates were determined and it was found cured resin containing 40% styrene showed the best balance of properties and EVER/glass fabric laminates exhibited better properties as compared to the epoxy/glass fabric laminates Dynamic mechanical analyses of the samples were done to determine the viscoelastic properties. Tg decreased significantly with increased styrene concentration due to increase in cross-linking density. Cross-sections of the cured samples, which failed during impact testing, have been critically studied through scanning electron microscopic (SEM) analysis to gain insight into the phase morphology.

Phenol-modified cardanol–formaldehyde novolac resins have been synthesized using equal proportions of phenol and cardanol. To this mixture of phenol and cardanol, 0.6 and 0.8 mol of formaldehyde were added separately, under acidic conditions, at five different temperatures ranging between 80 and 120°C with an interval of 10°C. This was carried out for a maximum period of 6 h. The free formaldehyde and free phenol contents were determined at regular time intervals to check the completion of the reaction. The synthesized novolacs have been studied by infrared spectroscopic analysis (FT-IR). The reaction between cardanol, phenol, and formaldehyde was found to follow a second-order rate kinetics. The overall rate constant (k) increased with the increase of temperature. Based on the value of rate constants, various other parameters such as activation energy (Ea), change in enthalpy (Δ H) and entropy (Δ S), and free energy change (Δ G) of the reaction were also evaluated. It was found that the condensation reaction of phenol and cardanol with formaldehyde was nonspontaneous and irreversible. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 380–389, 2010

Three samples of vinyl ester resins (VERs) were synthesized using bisphenol-A-based epoxy resins of varying epoxide equivalent weights (EEW) and acrylic acid in presence of triphenylphosphine as a catalyst at 80 ± 2°C. The cresyl glycidyl ether was used as reactive diluent during the synthesis of VERs. A suitable reaction mechanism was proposed and discussed for the reactions involving epoxide group and acid groups. This was further confirmed by infrared spectroscopic analysis. The maximum peak temperature from DSC were at 106.05°C, 114.20°C, and 128.86°C for benzoyl peroxide initiated VERs viz. samples V1CV, V2CV, and V3CV, respectively, increased with the increase of EEW of the parent epoxy resin. It has also been found that the films of VER having highest EEW of bisphenol-A epoxy resin showed best chemical resistance amongst all other VERs in this study. The mechanical properties such as hardness and flexibility also showed a similar trend. The thermal stability was found to decrease with the increase of EEW of bisphenol-A epoxy resin in the VERs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Cardanol-based novolac resins were separately prepared with different mole ratios of cardanol-to-formaldehyde with different acid catalysts. These resins were epoxidized with epichlorohydrin, in basic medium, at 120°C. The resins were, separately, blended with different weight percentages of carboxyl-terminated butadiene acrylonotrile copolymer and cured with polyamine. Structural changes during blending were studied by FTIR spectroscopic analysis. Coats–Redfern equation was utilized to calculate the kinetic parameters, viz., order of decomposition reaction (n), activation energy (E), pre-exponential factor (Z), and rate decomposition constant (k), for the decomposition of the samples. It was found that the degradation of the epoxies and their blend samples proceeded in two steps. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Five blend samples of cardanol-based epoxidized novolac resin containing varying concentrations of carboxyl-terminated poly(butadiene-co-acrylonitrile) (CTBN) ranging between 0 and 25 wt % with an interval of 5 wt % were prepared. The epoxidized novolac resin (ECF) was synthesized from the epoxidation of cardanol-based novolac-type phenolic resin (CF) with molar excess of epichlorohydrin (i.e., about 10 mol at 120°C in basic medium). The CF resin was synthesized with a molar ratio of 1 : 0.5 of CF using dicarboxylic acid catalyst such as succinic acid at 120°C for 5 h. The pure epoxy and its blend were cured with stoichiometric amounts of polyamine curing agent. The formation of various products during the synthesis of cardanol-based novolac resin, epoxidized novolac resin, and blending of epoxidized novolac resin with CTBN have been studied by Fourier transform infrared (FTIR) spectroscopic analysis. Further, a reaction mechanism for the step-growth reaction was proposed on the basis of the results of FTIR analysis. Also, the structures of CF and ECF were proposed on the basis of the results of nuclear magnetic resonance and MALDI-TOF mass spectroscopic analysis along with gel permeation chromatographic (GPC) analysis. GPC analysis resulted in Mn of 670 gmol−1. The blend sample having 15 wt % CTBN concentration showed minimum cure time, whereas the presence of CTBN in blend systems showed marginal change in the values of ΔH. A clear-cut two-step mass loss in dynamic thermogravimetric trace of unmodified and CTBN-modified systems was observed. Thermal stability of the blend sample containing 15 wt % CTBN into the pure epoxy resin was the highest among all other prepared systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Cardanol-based, novolac-type phenolic resins were synthesized with a cardanol-to-formaldehyde molar ratio of 1 : 0.7 with different dicarboxylic acid catalysts, including oxalic and succinic acids. These novolac resins were epoxidized with a molar excess of epichlorohydrin at 120°C in a basic medium. The epoxidized novolac resins were separately blended with different weight ratios of carboxyl-terminated butadiene–acrylonitrile copolymer (CTBN) ranging between 0 and 20 wt % with an interval of 5 wt %. All of the blends were cured at 120°C with a stoichiometric amount of polyamine. The formation of various products during the synthesis of the cardanol-based novolac resin and epoxidized novolac resin and the blending of the epoxidized novolac resin with CTBN was studied by Fourier transform infrared spectroscopy analysis. Furthermore, the products were also confirmed by proton nuclear magnetic resonance and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy analysis. The molecular weights of the prepared novolacs and their epoxidized novolac resins were determined by gel permeation chromatography analysis. The blend samples, in both cases, with 15 wt % CTBN concentrations showed the minimum cure times. These blend samples were also the most thermally stable systems. The blend morphology, studied by scanning electron microscopy analysis, was, finally, correlated with the structural and property changes in the blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Novolac resins having cardanol-to-formaldehyde mole ratios of 1:0.4, 1:0.5, and 1:0.6 were prepared by using aromatic sulphonic acid as the catalyst at four different temperatures ranging between 90°C and 120°C, with an interval of 10°C. Free formaldehyde and free phenol contents were determined at regular time intervals to check the completion of the reaction. The synthesized novolacs were characterized by Fourier-transform infrared spectroscopic analysis, nuclear magnetic resonance, and gel permeation chromatography. The reaction between cardanol and formaldehyde was found to follow second-order kinetics. The overall rate constant (k) increased with the increase of temperature. On the basis of the value of k, various other activation parameters such as activation energy (Ea), change in enthalpy (ΔH), entropy (ΔS), and free energy (ΔG) of the reaction were also evaluated. It was found that the condensation reaction of cardanol and formaldehyde with aromatic sulphonic acid was nonspontaneous and irreversible. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 559–572, 2009

The curing kinetics of blends of diglycidyl ether of bisphenol A (DGEBA), cycloaliphatic epoxy resins, and carboxyl-terminated butadiene-acrylonitrile random copolymer (CTBN) in presence of 4,4′-diamino diphenyl sulfone (DDS) as the curing agent was studied by nonisothermal differential scanning calorimetry (DSC) technique at different heating rates. The kinetic parameters of the curing process were determined by isoconversional method given by Malek for the kinetic analysis of the data obtained by the thermal treatment. A two-parameter (m, n) autocatalytic model (Sestak-Berggren equation) was found to be the most adequate selected to describe the cure kinetics of the studied epoxy resins. The values of Ea were found to be 88.6 kJ mol−1 and 61.6 kJ mol−1, respectively, for the studied two sample series. Nonisothermal DSC curves obtained using the experimental data show a good agreement with that theoretically calculated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Differential scanning calorimetric (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) of the blends of cycloaliphatic epoxy (CAE) resin toughened with liquid elastomer such as carboxyl terminated butadiene acrylonitrile copolymer (CTBN) have been carried out. Exothermal heat of reaction due to cross linking of the resin in the presence of diamino diphenyl sulphone (DDS, an amine hardener) showed a decreasing trend with increasing rubber concentration. Enhancement of thermal stability as well as lower mass loss of the epoxy-rubber blends with increasing rubber concentration have been observed in thermogravimetric analysis (TGA). Dynamic mechanical properties reflected a monotonic decrease in the storage modulus (E′) with increasing rubber concentration. The loss modulus (E″) and the loss tangent (tan δ) values, however, showed an increasing trend with rise of temperature up to a maximum (peak) followed by a gradual fall in both cases.

Different types of cardanol-based novolac-type phenolic resins are produced under a wide range of operating conditions for the application in the resin producing industries. Different operating conditions employed for the production of such resins result in different extent of conversion. In order to understand the system behavior, mathematical relationship between the process variables and the extent of conversion was established by employing the ‘Response surface methodology’. Geometrical representation of the mathematical models in three-dimensional surface plots served as a good aid in understanding the behaviour of reaction under different operating conditions. The maximum extent of conversion of the condensation reaction of cardanol and formaldehyde was found to be 93.0 percent at optimum sets of condition of reaction temperature, time, catalyst concentration and pH of the reaction mixture. All the predicted values for optimum process conditions were in good agreement with experimental data.

Resoles were prepared with different phenols, separately, with formaldehyde having phenol-to-formaldehyde molar ratio of 1 : 2 in basic medium at 70°C. These resoles were physically blended with different weight percentages of diglycidyl ether bisphenol-A (DGEBA)-epoxy resin. The blends were cured with 40, 50, and 60 wt % polyamide based on the total weight of the blend resin at 100°C. It was found that the blend system containing equal weight ratio of resole, prepared from p-cresol, and epoxy resins showed the least cure time with 40 wt % polyamide among all other blend systems. Also, the cured films of such blend systems showed the best chemical resistance, thermal stability, and hardness as compared to their other blend systems and blend counterparts. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Toughening of blend of diglycidyl ether of bisphenol-A (DGEBA) and 3,4 epoxy cyclohexylmethyl, 3′,4′-epoxycylohexane carboxylate, i.e. cycloaliphatic epoxy resin (CAE) with varying weight ratios (0–25 wt%) of carboxyl terminated butadiene acrylonitrile (CTBN) copolymer have been investigated. Fourier transform infrared (FTIR) spectroscopic analysis established that the interaction between oxirane groups of DGEBA, CAE and CTBN were responsible for characteristics peak shifts in the blends compared to their counterparts. Physico-mechanical properties of the prepared samples, e.g. tensile, flexural and impact strengths showed an optimum concentration of CTBN (15 wt%) into epoxy matrix, which offered maximum toughening. Thermal stability of the prepared samples was analyzed by dynamic thermogravimetric runs. Cross-sections of the cured samples which failed during impact testing have been critically studied through scanning electron microscopic (SEM) analysis to gain insight into the phase morphology.

Cardanol-based novolac-type phenolic resin was synthesized with a mole ratio 1.0:0.5 of cardanol-to-formaldehyde using a dicarboxylic acid catalyst such as succinic acid. The cardanol-based novolac-type phenolic resin may further be modified by epoxidation with epichlorohydrin excess at 393 K in a basic medium to duplicate the performance of such phenolic-type novolacs. Carboxyl-terminated butadiene acrylonitrile copolymer (CTBN) has been studied by various researches with diglycidyl ether of bisphenol-A (DEGBA) epoxy resin and epoxidized phenolic novolac resins. The epoxidized novolac resin was blended with different weight ratios of carboxyl-terminated butadiene acrylonitrile copolymer (CTBN) and cured with a stoichiometric amount of polyamine curing agent. The formation of various products during the synthesis of cardanol-based novolac resin, epoxodized novolac resin and blending of epoxidized novolac resin with CTBN has been studied by Fourier-transform infrared (FTIR) spectroscopic analysis. Further, the products were confirmed by a proton nuclear magnetic resonance (1H-NMR) spectroscopic analysis. The number average molecular weight was determined by a gel permeation chromatography (GPC) analysis. The blend sample, having 15 wt % CTBN concentration showed minimum cure time and most thermally stable systems.

The hypersonic velocity impact protection properties of carbon-nanotube-reinforced amorphous silicon carbide composites are investigated using molecular dynamics simulation. The projectile-impact-induced damage to target materials is analyzed for composite targets having perpendicular and parallel alignments of carbon nanotubes with respect to impact direction, and compared to that of pristine amorphous silicon carbide target. It was found that, in the considered range of impact velocities, the penetration depth is approximately the same for both CNT-reinforced composites and pristine a-SiC target. At short time-scales, damage to a target is defined by penetration depth of projectile and density rearrangements taking place in the target material. In the composite with carbon nanotubes aligned parallel to the impact direction, a channeling of damage to deeper regions of the target occurs. In the case of perpendicular alignment, the damage is confined to a narrow region underneath the penetrating projectile. For both considered composite samples, we found that a significant damping of the amplitudes of compressive shock-waves takes place, thus reducing the special extent of damage in composites as compared to that in the pristine a-SiC target.

Representative results of computer simulation and/or modeling studies of the nanomechanical and thermal transport properties of an individual carbon nanotube, silicon nanowire, and silicon carbide nanowire systems have been reviewed and compared with available experimental observations. The investigated nanomechanical properties include different elastic moduli of carbon nanotubes, silicon nanowires, and silicon carbide nanowires, all obtained within their elastic limits. Moreover, atomistic mechanisms of elastic to plastic transition under external stresses and yielding of carbon nanotubes under experimentally feasible temperature and strain rate conditions are discussed in detail. The simulation and/or modeling results on thermal properties, presented in this work, include vibrational modes, thermal conductivity and heat pulse transport through single carbon nanotubes, and thermal conductivity of silicon nanowires.

A kinetic study of the reaction of cardanol ( C ) and formaldehyde ( F ) (molar ratio 1:0.5) was carried out at four different temperatures ranging between 100 and 130 °C with an interval of 10 °C using three different catalyst systems. The reaction between cardanol and formaldehyde was found to follow second-order rate kinetics with all three catalyst systems. The change of the catalyst system affected the values of k , k 1 , and k 2 with temperature. In all the systems, the values of k 1 were found to be lower than the values of k 2 . Based on the values of rate constants, various other parameters such as activation energy ( E a ), change in enthalpy (Δ H ) and entropy (Δ S ), and free energy change (Δ G ) of the reaction were also evaluated. It was found that the condensation reaction of cardanol and formaldehyde with di- and tricarboxylic acids was anti-spontaneous and irreversible.

Blend samples were prepared by physical blending of nonglycidyl-type epoxy resin with varying weight ratios of carboxyl-terminated butadiene acrylonitrile (CTBN) copolymer ranging between 0 and 25 wt%. The blend samples were cured with stoichiometric quantity of diamine. A comparative study of prepared blend samples by Fourier transform infrared (FTIR) spectroscopy showed the modification as a result of chemical reactions between cycloaliphatic epoxy, CTBN, and 4,4′-diamino diphenyl sulfone. The impact strength of the blend systems increased up to 15 wt% addition of CTBN in the blend and decreased thereafter. The toughness and elongation at break increased, whereas tensile strength decreased up to 20 wt% loading of CTBN in the blends. Two-phase morphology appeared with the incorporation of CTBN in the cycloaliphatic epoxy resin matrix. © 2008 Wiley Periodicals, Inc. Adv Polym Techn 26:258–271, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20106