AB Block Research Articles

Vitrimers based on block copolymers with diverse block sequences

Vitrimers based on block copolymers give access to adaptable polymer networks where the resulting properties can be adjusted not only by the vitrimer chemistry itself but also can be influenced by the structure of the block copolymer. In this work, linear AB, ABA, and BAB block copolymers are introduced as backbones in vinylogous urethane vitrimers to produce crosslinked materials that are reprocessable and have a wide range of tunable mechanical properties. The narrow-disperse block copolymers were synthesized by photoiniferter reversible addition-fragmentation chain transfer polymerization (photoRAFT). Two different types of hydrophobic A blocks, poly(methyl methacrylate) and poly(ethyl methacrylate) with a higher glass transition temperature compared to the hydrophilic B block, poly(2-hydroxyethyl methacrylate), were chosen. The B block carries the functional groups for further modification to obtain acetoacetylated side groups, which are then transformed to vinylogous urethane crosslinks. It has been found that the architectures of backbones as well as the alkyl substituents in the side groups of the A block influence the final performance of the vitrimers. By adjusting block sequences, the mechanical properties can be varied from hard to tough to elastic materials corresponding to BAB, ABA, and AB block copolymer vitrimers, respectively. These materials are reprocessable and have self-healing as well as shape-memory properties.

The crosslinking and decrosslinking of fluorinated diblock copolymer from RAFT emulsion polymerization toward surface anti‐icing

AbstractHere, we demonstrate disulfide‐crosslinked polyfluoroacrylate AB block copolymer films with excellent anti‐icing properties. The fluorinated latexes of AB block copolymers were synthesized via two‐step reversible addition‐fragmentation chain‐transfer (RAFT) emulsion polymerization using polyacrylic acid and its sodium salts as the hydrophilic A‐block, and polyhexafluorobutyl acrylate as the hydrophobic B‐block. Diacetone acrylamide was copolymerized in different blocks as a crosslinking anchor. A disulfide‐containing compound dithiodipropionic acid dihydrazide was chosen as the crosslinking agent to form disulfide‐crosslinked fluorinated films to enhance the mechanical properties, surface properties, swelling properties, and anti‐icing properties of the films. It has proved that the crosslinking site has a great impact on the film formation process which in turn affects the film performance. The B‐block crosslinked films showed better resistance to water while the A‐block crosslinked films were more organic solution resistant. The A‐block crosslinked films also possessed better anti‐icing properties due to the high F/O value. Furthermore, decrosslinking experiments were conducted using a reductant tris(2‐carboxyethyl)phosphine hydrochloride to break the disulfide bond. The recycling rate of the B‐block crosslinked films could reach >90% while the recycling rate of the A‐block crosslinked films reached >75%.

Cyclic and Linear Tetrablock Copolymers Synthesized at Speed and Scale by Lewis Pair Polymerization of a One-Pot (Meth)acrylic Mixture and Characterized at Multiple Levels.

Cyclic block copolymers (cBCP) are fundamentally intriguing materials, but their synthetic challenges that demand precision in controlling both the monomer sequence and polymer topology limit access to AB and ABC block architectures. Here, we show that cyclic ABAB tetra-BCPs (cABAB) and their linear counterpart (lABAB) can be readily obtained at a speed and scale from one-pot (meth)acrylic monomer mixtures, through coupling the Lewis pair polymerization's unique compounded-sequence control with its precision in topology control. This approach achieves fast (<15 min) and quantitative (>99%) conversion to tetra-BCPs of predesignated linear or cyclic topology at scale (40 g) in a one-pot procedure, precluding the needs for repeated chain extensions, stoichiometric addition steps, dilute conditions, and postsynthetic modifications, and/or postsynthetic ring-closure steps. The resulting lABAB and cABAB have essentially identical molecular weights (Mn = 165-168 kg mol-1) and block degrees/symmetry, allowing for direct behavioral comparisons in solution (hydrodynamic volume, intrinsic viscosity, elution time, and refractive indices), bulk (thermal transitions), and film (thermomechanical and rheometric properties and X-ray scattering patterns) states. To further the morphological characterizations, allylic side-chain functionality is exploited via the thiol-ene click chemistry to install crystalline octadecane side chains and promote phase separation between the A and B blocks, allowing visualization of microdomain formation.

Population Fluctuation of Gram Pod Borer in Rabi Pulses of West Bengal

During the rabi season of 2021-22, a field research has been carried out at BCKV [District Seed Farm (AB Block)] Kalyani, Nadia, West Bengal for studying the pattern of incidence of gram pod borer or tomato fruit borer (Helicoverpa armigera Hubn.) in relation with prevailing meteorological parameters and to record the population fluctuation in four rabi pulse crops, viz., chickpea (var. KWR 108 and JAKI 9218), fieldpea (var. Rachna and VL 42), lentil (var. IPL 220 and L 4727) and grasspea (var. Prateek and Ratan). During the vegetative stage of the fieldpea, the Helicoverpa population first emerged, then gradually increased and declined near maturity; in lentil and grasspea it was recorded from flowering stage and persisted until maturity; in chickpea it was noticed from pod formation stage and continued up to maturity. None of the weather variables were significantly correlated with the Helicoverpa larvae population recorded on fieldpea and lentil while, regression studies denote that maximum (Max. T) and minimum (Min. T) temperature exhibited the most impact on the occurrence of Helicoverpa in grasspea and chickpea, respectively. The comparative study revealed that, Helicoverpa first appeared on lentil and field pea during the first week of January; then population appeared on grasspea during the end of second fortnight of January. Occurrence of the pest was noticed on lentil, field pea and grasspea in January and February and after that the population shifted to grasspea, fieldpea and chickpea during February to March. Chickpea was the most preferred crop as the highest population observed on this crop coinciding with pod formation stage.

Productive Germinal Center Responses Depend on the Nature of Stimuli Received by Anti-Insulin B Cells in Type 1 Diabetes-Prone Mice.

Islet autoantibodies, including those directed at insulin, predict type 1 diabetes (T1D) in mice and humans and signal immune tolerance breach by B lymphocytes. High-affinity insulin autoantibodies and T follicular helper cell involvement implicate germinal centers (GCs) in T1D. The VH125SD BCR transgenic model, in which 1-2% of peripheral B lymphocytes recognize insulin, enables direct study of insulin-binding B cells. Our prior studies showed that anti-insulin B cell receptor transgene site-directed to H chain locus mice fail to generate insulin Ab following T-dependent immunization, but it was unclear whether anti-insulin B cells were blocked for GC initiation, survival, or differentiation into Ab-secreting cells. Here, we show that insulin-binding B cells in T1D-prone anti-insulin B cell receptor transgene site-directed to H chain locus mice can spontaneously adopt a GC phenotype and undergo class switching to the IgG1 isotype, with little if any switching to IgG2b. T-dependent immunizations with insulin SRBC or insulin CFA drove anti-insulin B lymphocytes to adopt a GC phenotype, despite blunted insulin Ab production. Dual immunization against self (insulin) and foreign (4-hydroxy-3-nitrophenylacetyl hapten conjugated to keyhole limpet hemocyanin) Ags showed an anti-insulin (but not anti-4-hydroxy-3-nitrophenylacetyl) Ab block that tracked with increased expression of the apoptosis marker, activated caspase 3, in self-reactive GC B cells. Finally, T-independent immunization with insulin conjugated to Brucella abortus ring test Ag released immune tolerance to allow robust expansion of anti-insulin GC B cells and IgG-switched insulin Ab production. Overall, these data pinpoint GC survival and Ab-secreting cell differentiation as immune tolerance blocks that limit T-dependent, but not T-independent, stimulation of anti-insulin B cell responses.

An equation driven quality classification of (a)symmetric gradient, gradient-block, block-gradient-block and block copolymers

The control of the A/B comonomer distribution over individual chains targeting block and/or gradient monomer distributions is essential to control the macroscopic properties of the resulting copolymers. Matrix-based kinetic Monte Carlo simulations allow to compare each chain of a representative copolymer sample with the desired (mathematical) composition, as defined by monomer inclusion probabilities (PA/B) taking the B-functionalization degree (B-Func) as maximally 50%. A so-called average deviation (SD∗ value) results per chain, with a close to 0 average (normalized) structural deviation 〈SD〉 corresponding to an almost perfect structure and a 〈SD〉 close to 1 representing the worst case scenario of a B-homopolymer. The previously assigned 〈SD〉 transitions from excellent to good and from good to poor are, however, somewhat arbitrary, e.g. for both symmetric gradient and block copolymers a threshold 〈SDGood/Poor〉 of 0.3 is currently utilized and only for specific asymmetric cases (30% B-Func block, block-gradient, and gradient) 〈SDExc/Good〉 and 〈SDGood/Poor〉 values have been reported. The present work puts forward an equation driven method to obtain 〈SD〉 threshold values, minimizing the arbitrary nature of the quality classification for a given copolymer type and more importantly aligning the quality assessment for any copolymer type containing block and/or gradient elements. Emphasis is on the complete SD distribution (instead of only its average) for (a)symmetric AB gradient, block A-gradient AB, block A-gradient AB-block B, and AB block copolymers by introducing the overall gradient and block fractions (fGr/Bl) as a novel parameter alongside the targeted degree of polymerization (target DP) and B-Func. Ideal theoretical structures with equal chain length and a perfect implementation of the desired PA/B profiles are dealt with, as they represent the best case an actual synthesis recipe could deliver in the limit. It is shown that the log-normal distribution can be reliably used to approximate the SD distribution, as coefficients of determination (R2) very close to one follow for (a)symmetric copolymers . It is further showcased that threshold values for gradient dominant structures must be higher than those for block-like structures and that well-defined symmetric structures are more difficult to achieve than asymmetric ones. It is also recommended to report 〈SD〉 together with its standard deviation σSD.

Core-Shell Gyroid in ABC Bottlebrush Block Terpolymers.

Block polymer self-assembly provides a versatile platform for creating useful materials endowed with three-dimensional periodic network morphologies that support orthogonal physical properties such as high ionic conductivity and a high elastic modulus. However, coil configurations limit conventional linear block polymers to finite ordered network dimensions, which are further restricted by slow self-assembly kinetics at high molecular weights. A bottlebrush architecture can circumvent both shortcomings owing to extended backbone configurations due to side chain crowding and molecular dynamics substantially free of chain entanglements. However, until now, network morphologies have not been reported in AB bottlebrush block copolymers, notwithstanding favorable mean-field predictions. We explored the phase behavior by small-angle X-ray scattering of 133 poly(ethylene-alt-propylene)-b-polystyrene (PEP-PS) diblock and PEP-PS-PEO triblock bottlebrush copolymers prepared by ring-opening metathesis polymerization (ROMP) of norbornene-functionalized poly(ethylene-alt-propylene) (PEP), poly(styrene) (PS), and poly(ethylene oxide) (PEO) macromonomers with total backbone degrees of polymerization Nbb between 20 and 40. The PEP-PS diblocks exhibited only cylindrical and lamellar morphologies over the composition range of ca. 30-70%. However, addition of variable-length bottlebrush PEO blocks to diblocks containing 30-50% PS led to the formation of a substantial core-shell double gyroid (GYR) phase window containing 20 bottlebrush triblock specimens, which is the focus of this report. Encouragingly, the GYR unit cell dimensions increased as d ∼ Nbb0.92, portending the ability to access larger network dimensions than previously obtained with linear AB or ABC block polymers. This work highlights extraordinary opportunities associated with applying facile ROMP chemistry to multiblock bottlebrush polymers.

Simple and Rapid Access toward AB, BAB and ABAB Block Copolyesters from One-Pot Monomer Mixtures Using an Indium Catalyst.

The synthesis of well-defined block copolymers from one-pot monomer mixtures is particularly challenging when monomers are from the same class and show similar reactivity. Herein, an indium-based catalyst that shows comparable rates in the ring-opening homopolymerization of β-butyrolactone (β-BL) and ε-decalactone (ε-DL), demonstrates monomer-selective behavior in one-pot copolymerizations of β-BL and ε-DL. This provides simple and rapid access to well-defined di-, tri-, or tetra-block copolyesters from monomer mixtures. The sequence-controlled nature of these polymers was confirmed by kinetic analysis, 13C{1H} NMR spectroscopy, DSC, and TGA measurements.

Stabilizing a Double Gyroid Network Phase with 2 nm Feature Size by Blending of Lamellar and Cylindrical Forming Block Oligomers

Molecular dynamics simulations are used to study binary blends of an AB-type diblock and an AB2-type miktoarm triblock amphiphiles (also known as high-χ block oligomers) consisting of sugar-based (A) and hydrocarbon (B) blocks. In their pure form, the AB diblock and AB2 triblock amphiphiles self-assemble into ordered lamellar (LAM) and cylindrical (CYL) structures, respectively. At intermediate compositions, however, the AB2-rich blend (0.2 ≤ xAB ≤ 0.4) forms a double gyroid (DG) network, whereas perforated lamellae (PL) are observed in the AB-rich blend (0.5 ≤ xAB ≤ 0.8). All of the ordered mesophases present domain pitches under 3 nm, with 1 nm feature sizes for the polar domains. Structural analyses reveal that the nonuniform interfacial curvatures of DG and PL structures are supported by local composition variations of the LAM- and CYL-forming amphiphiles. Self-consistent mean field theory calculations for blends of related AB and AB2 block polymers also show the DG network at intermediate compositions, when A is the minority block, but PL is not stable. This work provides molecular-level insights into how blending of shape-filling molecular architectures enables network phase formation with extremely small feature sizes over a wide composition range.

Sliding dynamics of ring on a fixed rod-like block copolymer in rotaxane: Molecular dynamics simulations vs Lifson-Jackson formula

Rotaxane is a mechanically interlocked molecule in which ring chains are threaded onto a linear axial polymer chain, and a typical feature of rotaxane is that the ring chains can slide along the axial chain. In this study, molecular dynamics simulations and Lifson-Jackson formula are performed to examine the sliding dynamics of ring chain threaded on a fixed rod-like AB block copolymer consisting of A and B blocks in which the A-block composed of NA monomers is attractive to the ring chain, while the B-block with NB monomers is repelled from the ring chain. From a series of studies on ring sliding along the AB block copolymer with the repeat unit of ANABNB, we find that the sliding dynamics of ring relies strongly on the block length of (NA+NB), the volume fraction fa of A-block as well as the block-ring interaction ε. First, the sliding diffusion coefficient D of ring decreases sharply by several orders magnitude with an increase in block length or block-ring interaction strength. Next, the sliding dynamics has a strongly non-monotonic dependence on fa, and the slowest diffusion motion occurs for ring threaded onto the symmetric block copolymer with fa=0.5. From the view of free energy potential, both the width of free energy potential well and the height of free energy potential barrier govern the sliding diffusion behavior of ring chain. According to potential of mean force (PMF) of ring sliding along the fixed rod-like block copolymer, we find that our results are good agreement with the theoretical analysis using the Lifson-Jackson formula. Our investigation can provide a simple as well as practical model to study the diffusion of particle in a periodic medium, which is one of the interesting problems in many different fields of sciences, such as physics, chemistry and biology.

One-Pot Precision Synthesis of AB, ABA and ABC Block Copolymers via Switchable Catalysis.

The switchable catalysis using a commercial salenMn catalyst was firstly developed and applied in the one-pot selective copolymerization from anhydrides, epoxides, CO2 and ϵ-caprolactone (ϵ-CL) mixtures for the precise synthesis of AB, ABA and novel ABC block copolymers. The observed unique double switch process comprising three different polymerization cycles was rationalized by theoretical calculations. Surprisingly, the first block turned out to be an efficient macromolecular initiator for the consecutive introduction of carbonate linkages into copolymers, albeit with dominant cyclization with the catalyst alone. Further, through the selective reaction on different epoxides, the switchable copolymerization of up to five monomers was achieved yielding well-defined multi-block copolymers with structural diversity and functionality.

One‐Pot Precision Synthesis of AB, ABA and ABC Block Copolymers via Switchable Catalysis

AbstractThe switchable catalysis using a commercial salenMn catalyst was firstly developed and applied in the one‐pot selective copolymerization from anhydrides, epoxides, CO2 and ϵ‐caprolactone (ϵ‐CL) mixtures for the precise synthesis of AB, ABA and novel ABC block copolymers. The observed unique double switch process comprising three different polymerization cycles was rationalized by theoretical calculations. Surprisingly, the first block turned out to be an efficient macromolecular initiator for the consecutive introduction of carbonate linkages into copolymers, albeit with dominant cyclization with the catalyst alone. Further, through the selective reaction on different epoxides, the switchable copolymerization of up to five monomers was achieved yielding well‐defined multi‐block copolymers with structural diversity and functionality.

Comparative Thermodynamic Studies of the Micellization of Amphiphilic Block Copolymers before and after Cyclization.

The enthalpy and entropy of micellization in water, ΔHmic and ΔSmic, respectively, of three linear amphiphilic BAB block copolymers consisting of either poly(methyl acrylate) (Mn ∼ 1200 and 700 Da) or poly(ethyl acrylate) (Mn ∼ 800 Da) as hydrophobic (B) segments and poly(ethylene oxide) (PEO) as the hydrophilic (A, Mn ∼ 3000 Da) segment were determined by isothermal titration calorimetry (ITC). The ΔHmic and ΔSmic of the cyclic AB block copolymers obtained by cyclization of the linear triblock copolymers were determined under the same conditions. The ΔHmic value of the cyclic copolymers was smaller than that of their linear precursors. The ΔSmic value showed the same trend, but the relative difference between the cyclized and linear copolymers was less pronounced. The hydrodynamic diameter (Dh), critical micelle concentration (CMC), molecular weight (Mw-mic), and second virial coefficient (A2) of the micelles were determined. The Dh value of the cyclic copolymer micelles was smaller than the linear counterpart. On the other hand, the CMC value became larger, whereas the A2 value was comparable or increased by cyclization. Overall, the results suggest that, in the unimer state, the hydrophobic segments of the cyclized copolymers form a tightly coiled structure to minimize contact with water, resulting in the smaller ΔHmic value. Contrary to the linear copolymer micelles, the cyclic copolymer micelles have no "dangling chains", which may explain the topology-driven slight difference in the ΔSmic value.

Distinctive Dielectric Permittivity of Hierarchical Nanostructures with Ordered Nanoparticle Networks Self-Assembled from AB-g-NP/AC Block Copolymer Mixtures.

Directing nanoparticles into ordered organization in polymer matrix to improve macroscopic properties of nanocomposites remains a challenge. Herein, by means of theoretical simulations, we show the high permittivity of hybrid nanostructures designed with mixtures of AB block copolymer-grafted nanoparticles and lamella-forming AC diblock copolymers. The grafted nanoparticles self-assemble into parallel stripes or highly ordered networks in the lamellae of the AC diblock copolymers. The ordered nanoparticle networks, including honeycomb-like and kagomé networks, provide bending and conductive pathways for concentrating electric fields, which results in the improvement of the permittivity. We envisage that this strategy will open a gateway to prepare hierarchically ordered functional nanocomposites with distinctive dielectric properties.

Bio-based ABA triblock copolymers with central degradable moieties

A set of (poly-α-methylene-γ-butyrolactone)–co-(poly-δ-decalactone)–co-(poly-α-methylene-γ-butyrolactone) (PMBL-co-PDL-co-PMBL) ABA block copolymers containing different stimuli cleavable groups at the central point of the poly(δ-decalactone) (PDL) block were synthesized by a combination of Ring Opening Transesterification Polymerization (ROTEP) of DL, diol end-group functionalization as α-bromoester and Atom Transfer Radical Polymerization (ATRP) of α -methylene-γ-butyrolactone (MBL). Diols containing acetal, spiroacetal, thioacetal and disulphide units were used as initiators for the bulk room temperature controlled polymerization of δ-decalactone (DL) using 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as catalyst. PDL diols were functionalized in a one-pot two-steps procedure using N-(2-bromoisobutyryl)imidazole (BiB-Im). The resulting macroinitiators were chain extended by atom transfer radical polymerization (ATRP) in DMF at 50 °C using MBL as methacrylic-like monomer and the conventional CuCl/CuCl2/2,2′-bipyridine catalyst system. The cleavage behaviour of the copolymers under reductive, acidic and photooxidative conditions has been studied and the resulting AB block copolymers structurally characterized.

Modular Genetic Code Expansion Platform and PISA Yield Well-Defined Protein-Polymer Assemblies.

We present a modular platform from which biohybrid protein-polymer nanostructures can be generated in a straightforward and facile manner. Specifically, an aqueous polymerization-induced self-assembly (PISA) AB block copolymerization system was derived from a mutant superfolder green fluorescent protein (sfGFP) as the solvophilic, stabilizing A block. By genetically encoding sfGFP with an isobutyryl bromide functionality, we grafted a quintessential atom-transfer radical polymerization initiation site with hydroxypropyl methacrylate (HPMA) to form the solvophobic B block. Monitoring nanostructure formation using dynamic light scattering, gel permeation chromatography, and transmission electron microscopy revealed uniform micellar morphologies. The radii of the micelles increased with increasing HPMA block length, resulting in nanoparticle sizes ranging from 15 to 48 nm. Solvophilic stabilization afforded by the encoded sfGFP makes this an ideal PISA initiator, and we posit this platform has potential for generating complex biohybrid nanostructures for other protein-polymer systems.

Genetic diversity analysis in bread wheat (Triticum aestivum L.) under Gangetic Alluvium Zone of West Bengal

Forty-nine genotypes of bread wheat (Triticum aestivum L.) were screened at District farm, AB Block, B.C.K.V., Kalyani,&nbsp;Nadia, West Bengal during Rabi season for two years, i.e. 2015-2016 and 2018-2019 following Randomized Block&nbsp;Design with two replications to study genetic diversity following the Mahalanobis D2 statistics and principal component&nbsp;analysis. The highest contribution towards total divergence was yield plant-1 followed by the number of grains spike-1,&nbsp;plant height, weight of grains spike-1 and the test weight. The maximum inter-cluster distance was observed between&nbsp;cluster IX and I (86.392), followed by clusters VIII and IX (82.829) indicating that the genotypes being represented in&nbsp;these clusters were distantly related. Therefore, any two genotypes selected from these two clusters may be utilized&nbsp;in crossing programs to synthesis potential high yielding genotypes. Principal component analysis (PCA) extracted 5&nbsp;principal components explaining 80% to genetic variation. The PCA suggested that the genotypes are highly diverse.

Pattern of Capsule and Seed Development in Sesame (Sesamum indicum L.) as Influenced by Seed Priming

Aim: To study the influence of seed priming on the pattern of capsule and seed development in sesame.&#x0D; Place and Duration of Study: The field experiment was conducted during the pre kharif seasons of 2017-2018 and 2018-2019 in sesame variety Savitri at AB Block farm, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia, West Bengal, India.&#x0D; Methodology: Experiment was laid out in split plot design with 3 replications. Ten schedules of seed priming viz T1 (KNO3 @ 10 mM), T2 (KNO3 @ 20 mM), T3 (KNO3 @ 50 mM), T4 (KH2PO4 @ 50 mM), T5 (KH2PO4 @ 100 mM),T6 (KH2PO4 @ 200 mM), T7 [Polyethylene glycol (PEG) 6000 @ -0.4 MPa], T8 [Polyethylene glycol (PEG) 6000 @ -0.3 MPa], T9 [Polyethylene glycol (PEG) 6000 @ -0.2 MPa], T10 Distilled water (Hydro priming) along with control T11 (Dry seed) were taken as main plot treatment and stage of harvest was considered as sub plot treatment. The pattern of capsule and seed development was studied at 10 days after anthesis (DAA), 20 days after anthesis (DAA), 30 days after anthesis (DAA), 40 days after anthesis (DAA) and 50 days after anthesis (DAA) interval. Ten plants from each replication and in each treatment were selected at random to record data on morphological and physiological characters.&#x0D; Results: Fresh capsule length, fresh capsule breadth, fresh capsule weight, fresh seed weight and dry seed weight showed a steady increase up to 40 days after anthesis (DAA) then decreased slowly up to maturity.&#x0D; Conclusion: Considering seed yield and quality parameters, T7 [Polyethylene glycol (PEG) 6000 @ -0.4 MPa] and T9 [Polyethylene glycol (PEG) 6000 @ -0.2 MPa] appears to be ideal among the treatments for quality seed production in sesame.

Growth, Yield, Seed and Seedling Quality Parameters of Rapeseed-mustard Varieties under Different Seed Priming Options

Rationale: Crop production and quality of produce get affected by drought, stand establishment and low availability of nutrients. Apart from various prevailing methods, seed treatment through priming now-a-days has been found to noticeably improve crop establishment for increasing seed yield and quality.&#x0D; Aim: To study the effect of various seed priming options on rapeseed-mustard varieties.&#x0D; Place of Study: A field experiment was conducted at AB Block Farm, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia, West Bengal, India during winter season of 2017-2018.&#x0D; Methodology: Experiment comprised six rapeseed-mustard varieties (Anushka, Sanchita, TBM-143,TBM-204, Kranti and Pusa Bold) in main plot and five seed priming options (KH2PO4 @ 0.15 mol 100 ml water-1 5 g seeds-1, KNO3 @ 0.1 mol 100 ml water-1 5 g seeds-1, PEG 6000 @ -0.3 MPa 100 ml water-1 5 g seeds-1, hydro priming @ 100 ml 5 g seeds-1 and control) in subplot, replicated thrice in a split plot design. Observations on growth and yield contributing parameters were recorded from the field. Further, various quality parameters of seed and seedlings were evaluated in the laboratory. Data on all the parameters were finally statistically analyzed.&#x0D; Results: Among the varieties, Pusa Bold performed better in terms of growth, yield contributing parameters and seed yield under seed priming through either KH2PO4 @ 0.15 mol 100 ml water-1 5 g seeds-1 or PEG 6000 @ -0.3 MPa 100 ml water-1 5 g seeds-1. Seed and seedling quality parameters such as root and shoot lengths, seedling fresh and dry weights, germination % and vigour index were also improved under the same.&#x0D; Conclusion: Cultivation of mustard variety, Pusa Bold by seed priming through any of those two chemicals (KH2PO4 or PEG 6000) can be recommended for New alluvial zone of West Bengal, India.

Poly(diallyldimethylammonium) based poly(ionic liquid) di- and triblock copolymers by PISA as matrices for ionogel membranes

Poly(diallyldimethylammonium)-b-polystyrene AB and ABA block copolymers were synthesized using MADIX under PISA conditions. Ionogels for sodium batteries were prepared using the poly(ionic liquid) triblock copolymers.