Acrylonitrile Research Articles

Synthesis and Characterization of Poly(methyl acrylate)-grafted-Sodium Salt of Partially Carboxymethylated Tamarind Kernel Powder

Ceric ammonium nitrate (CAN)-initiated graft copolymerization of methyl acrylate (MA) onto sodium salt of partially carboxymethylated tamarind kernel powder (Na-PCMTKP, DS = 0.15) was studied in an aqueous medium by solution polymerization technique. The growth of the graft reaction was monitored gravimetrically. The role of various synthesis variables on the grafting yields was examined to achieve the maximum graft yields (%G = 278.27, %GE = 94.38, %Hp = 5.62) and the influence of the synthesis variables in the graft copolymerization has been discussed. The reactivity of methyl acrylate (MA) towards graft copolymerization was compared with that of acrylonitrile (AN) on the basis of the results obtained from the earlier studies and plausible explanation was furnished for the observed reactivity of both the monomers towards grafting. The evaluated optimized reaction conditions were utilized to study the effect of reaction medium on grafting and it was found that reaction medium plays an important role in graft copolymerization. In order to ascertain the grafting, characterization of the samples made by FTIR, TGA and SEM was conducted. The synthesized novel graft copolymer may find potential application to be used as metal adsorbents.

Cross-linked composite proton conductive membranes

Using UV-curing technique the proton conductive polymer materials based on acrylic monomers: 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylic acid (AA) and acrylonitrile (AN), cross-linked by varying amounts of N,N'-methylene(bis)acrylamide (MBA), and the hybrid polymer/inorganic membrane of the same content with addition of sol-gel system (SGS) based on 3-methacryloxypropyl trimethoxysilane (MAPTMS) and tetraethoxysilane (TEOS) were synthesized. The obtained materials were characterized by analysis of thermal, mechanical and morphological properties. Proton conductivity and water uptake were found to depend on the level of cross-linking of the materials. The value of proton conductivity of the hybrid membrane was sufficiently high reaching 3.46 × 10-2 S cm-1.

Akrylonitryl. Metoda oznaczania w powietrzu na stanowiskach pracy Anna Jeżewska, Agnieszka Woźnica

Acrylonitrile (AN) is highly flammable, colorless liquid with an unpleasant odor. Acrylonitrile is used in industry to produce polyacrylonitrile (PAN) and its copolymers. Acrylonitrile can cause cancer. The aim of this study was to develop a method for determining acrylonitrile in workplace air which will allow determination of its concentrations at the level of 0.1 mg/m3 . The method was based on adsorption of acrylonitrile vapors on activated carbon, desorption with acetone solution in carbon disulfide and chromatographic analysis of the obtained solution. The study was performed using a gas chromatograph (GC) with a flame ionization detector (FID) equipped with a DB-VRX capillary column (60 m × 0.25 mm, 1.4 µm). The method was validated in accordance with the requirements of Standard No. EN 482. The method allows the determination of acrylonitrile in workplace air at the concentration range from 0.1 to 2 mg/m3. The method for determining acrylonitrile has been recorded in the form of an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Unraveling the effect of Ti doping on the sensing properties of AlN nanotubes toward acrylonitrile gas

The adsorption of acrylonitrile (AC) is explored onto a pure and a Ti-doped AlN nanotube (AlNNT) through density functional theory computations. An adsorption energy of (Ead) −6.8 kcal/mol is predicted when AC comes nearer the pure AlNNT, which shows that the adsorption is weak. Also, there is no considerable change in the electronic properties of the pure AlNNT. Doping the AlNNT with titanium (Ti) improves its performance, making it more reactive and sensitive to AC. Our calculations of standard Gibbs free energy of formation indicate that replacing an Al atom in the structure of the AlNNT with a Ti atom is more favorable than an N atom. Doping a Ti atom into the surface of the AlNNT changes Ead of AC from −6.8 to −22.2 kcal/mol. The sensing response significantly rises to 94.7 after Ti-doping, which shows that there is an increase in the electrical conductivity of the AlNNT. Finally, we show that the Ti-doped AlNNT can selectively detect AC in the presence of HCN, formaldehyde, ethanol, toluene, and acetone. The recovery time for the desorption of AC from the surface of the Ti-doped AlNNT is computed to be 15.0 s, which has a short recovery time.

Investigation of the chemical changes during the thermal treatment of acrylonitrile‐co‐methyl acrylate‐polymer (polyacrylonitrile‐precursor) focusing on the fate of the methyl acrylate moiety

AbstractSeventeen samples of acrylonitrile (AN)‐co‐methyl acrylate (MA)‐polymer (MA content 0–11 mol%) are examined. Several selective isotopic labelings are employed (d1‐MA, d2‐MA, 13CO‐MA, CD3‐MA, d1‐AN, d2‐AN, and 15N‐AN). The thermal treatment under inert atmosphere is investigated to gain insight into the chemical transformation mechanisms concerning the MA sub‐unit. The volatiles are determined by means of evolved gas analysis (EGA) (Fourier transform infrared [FTIR] and GC/MS). Methanol is found for the first time as one decisive volatile stemming from the MA sub‐unit, next to water and carbon dioxide. In addition, methylamines are proven to be formed by reaction of ammonia with the MA sub‐unit, while a similar reaction of hydrogen cyanide (HCN) yielding in acetonitrile could be ruled out. Several volatile compounds could even be quantified. The non‐volatile polymeric material is characterized by means of simultaneous thermal analysis (differential scanning calorimetry, thermogravimetric analysis), in‐situ‐FTIR spectroscopy and sophisticated solid‐state NMR methods. Selected defined model compounds are synthesized and analyzed for comparison. Detailed reaction mechanisms for the thermal transformation are concluded from the results, pointing in particular to the importance of ammonia for all processes as stoichiometric and/or catalytic reagent.

Laboratory observation and astronomical search of 1-cyano propargyl radical, HCCCHCN

Context. The reaction between carbon atoms and vinyl cyanide, CH2CHCN, is a formation route to interstellar 3-cyano propargyl radical, CH2C3N, a species that has recently been discovered in space. The 1-cyano propargyl radical (HC3HCN), an isomer of CH2C3N, is predicted to be produced in the same reaction at least twice more efficiently than CH2C3N. Hence, HC3HCN is a plausible candidate to be observed in space as well. Aims. We aim to generate the HC3HCN radical in the gas phase in order to investigate its rotational spectrum. The derived spectroscopic parameters for this species will be used to obtain reliable frequency predictions to support its detection in space. Methods. The HC3HCN radical was produced by an electric discharge, and its rotational spectrum was characterized using a Balle-Flygare narrowband-type Fourier-transform microwave spectrometer operating in the frequency region of 4–40 GHz. The spectral analysis was supported by high-level ab initio calculations. Results. A total of 193 hyperfine components that originated from 12 rotational transitions, a- and b-type, were measured for the HC3HCN radical. The analysis allowed us to accurately determine 22 molecular constants, including rotational and centrifugal distortion constants as well as the fine and hyperfine constants. Transition frequency predictions were used to search for the HC3HCN radical in TMC-1 using the QUIJOTE survey between 30 and 50 GHz. We do not detect HC3HCN in TMC-1 and derive a 3σ upper limit to its column density of 6.0 × 1011 cm−2.

Removal of as(V), Cr(VI) and Cr(III) heavy metal ions from environmental waters using amidoxime and quaternized hydrogels

Acrylonitrile (AN) and 1-vinyl imidazole (VI) based hydrogel was prepared in bulk (macro) dimensions via redox polymerization technique. Afterward, this hydrogel was quaternized (positively charged) and exposed to the amidoximation reaction. The prepared hydrogels (quart-p(AN-co-VI), amid-p(AN-co-VI) and p(VI)) characterized using fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). Swelling experiments were performed gravimetrically at room temperature in deionized water and different pH solution. Water absorbencies of both amidoximated hydrogels and quaternized hydrogels were founded to be high. Prepared hydrogels were used to remove heavy metal ions such as arsenic(V) (As(V)), Chromium(VI) (Cr(VI)) and Chromium(III) (Cr(III)) from aqueous media. The sorption of As(V), Cr(VI) and Cr(III) metal ions by hydrogels were carried out at different initial metal ion concentrations, different pHs, different times in batch sorption experiments at 25oC. The maximum metal ion sorption capacity by all hydrogels was in the order: As(VI)>Cr(VI)>Cr(III). The maximum sorption capacity for As(VI), Cr(VI) and Cr(III) ions was found to be 598, 303.8 and 4.9 mg g-1 for amid-p(AN-co-VI), respectively. As result of, amidoximated hydrogels have more sorption capacity to metal ions than quaternized hydrogels. Three different kinetic models (pseudo first order, pseudo second order and intraparticle diffusion model) were also used to investigate the sorption mechanisms. Furthermore, the Langmuir and Freundlich sorption isotherms were investigated for these metal ions. As a result of, amidoximation and quaternization of AN and VI based hydrogels have been a promising technique to increase the sorption rate and capacity of hydrogels and are thought to provide great advantages in the removal of metal ions from wastewaters. Especially, among the p(AN-co-VI) modification processes, amidoximation reaction was found to give better results than quaternization reaction. Prepared hydrogels were found to be more selective than Cr(III) versus As(V) and Cr(VI).

Gas-phase formation of interstellar nucleobases from dehydrogenated formamide and vinyl cyanide

Context. Cytosine, thymine, and uracil are three of the five primary nucleobases that function as the fundamental units of the genetic code in nucleic acids. In searching the extraterrestrial origins of microscopic life, previous studies have reported formation routes of nucleobases in interstellar ice analogs. The present work explores the possibility that nucleobases could form from small molecules through gas-phase reactions in the interstellar medium (ISM). Aims. We aim to search energetically favorable synthetic routes toward the formation of cytosine, thymine, and uracil via gas-phase reactions, using first principles calculations. Based on the computation of a reaction energy barrier and reactant formation energy, we tried to identify the specific interstellar environments favorable to the formation of the nucleobases, with respect to the previously reported detection of relevant reactants in the ISM. Methods. Density functional theory calculations were carried out to investigate the chemical reaction pathways using the M06 functional with 6-31+G(d,p)/6-311++G(d,p) basis sets. An ab initio Møller-Plesset perturbation theory in the second order (MP2) was also used to corroborate the results. Results. We report synthetic routes toward the formation of cytosine, thymine, and uracil through gas-phase reactions between partially dehydrogenated formamide (H2NCHO) and vinyl cyanide (H2CCHCN). The most energetically favorable pathway to the formation of 1H-pyrimidin-2-one (C4H4N2O), a direct precursor of nucleobases, was found in a molecule-radical reaction between HNCHO and H2CCHCN, with an energy barrier of 19.3 kcal mol−1. The energy barriers for the optimal reaction pathways between C4H4N2O and amino, methyl, or hydroxyl to finally produce cytosine, thymine, or uracil are about 11.3, 18.6, or 19.9 kcal mol−1, respectively. Conclusions. The optimal energy barriers of 19.3 and 23.8 kcal mol−1 roughly correspond to a reaction rate coefficient of 10−11 cm3 s−1 at 180 and 220 K, respectively. This indicates that the reaction could be thermally feasible through a gas-phase reaction in hot molecular cores or in the inner part of the protoplanetary disks. In contrast, the energy barriers for the reactions between other dehydrogenated radicals and molecules are relatively high, which corresponds to the extinction energy of far-ultraviolet photons in photo-dissociation regions. Furthermore, the computed pathways suggest that prior H migration in the reactants could be the key rate-determining process for the synthesis of the primary nucleobases.

Mechanistic approach of SO4•−/•OH radical toward target pollutants degradation simultaneously enhanced activity and stability of perovskite-like catalyst SrCuxNi1-xO3

• A novel catalyst SrCu x Ni 1-x O 3 were synthesized by citric solgel method. • In-situ generated reactive species SO 4 •– and • OH both play major role on degradation. • Treatment system 0.6SCN/PMS provided very low treatment cost 50.72 $/m 3 of aqueous solution. • The possible degradation pathways of acrylonitrile and acrylamide were proposed. In this study, the degradation of highly toxic pollutants acrylonitrile (ACN) and acrylamide (ACM) by peroxymonosulfate (PMS) activation with series perovskite-like catalyst SrCu x Ni 1-x O 3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) were studied systematically in the batch experiments. Synthesized catalysts were characterized by various analytical techniques e.g., XRD, FTIR, FESEM with EDAX, TEM, XPS and EPR spectroscopy. Subsequently, effects of key parameters viz., PMS dosage, catalyst dosage, pH and reaction temperature were evaluated on the degradation efficiency and simultaneously evaluated the PMS utilization efficiencies along with PMS consumption. Catalyst 0.6SCN exhibited the highest catalytic activity and maximum removal of acrylonitrile (96%) and acrylamide (81%) along with 86% PMS consumption were observed at optimum operatizing conditions. In addition, stability and recyclability of 0.6SCN catalyst were assessed and removal efficiency of acrylonitrile suppressed 6% and acrylamide suppressed 11% over the fourth cycle of experiments along with very low leaching of Cu and Ni observed. Furthermore, electron paramagnetic resonance (EPR) and quenching experimental studies reveal that in-situ generated both reactive species (SO 4 •– and • OH) were accountable for the removal of acrylonitrile and acrylamide synergistically in 0.6SCN/PMS system. Reaction pathways of acrylamide and acrylonitrile degradation were proposed based on the intermediate detected through GC–MS analysis and literature studies. Finally, the operating cost of treatment process was assessed 50.62$/m 3 of wastewater in 0.6SCN/PMS system.

Highly promising recycled low-density polyethylene sheet adsorbents for uranium recovery from seawater

ABSTRACT Amidoximated absorbers based on recycled low-density polyethylene (LDPE) sheets (food packaging bags, breast milk storage bags and grocery bags) for uranium recovery from seawater were investigated. Simultaneous irradiation grafting by gamma ray was performed. A 40-µm thick LDPE sheet submerged in the acrylonitrile (AN): methacrylic acid (MAA) solution of 60: 40 v/v% with the optimal gamma ray dose of 40 kGy showed the highest cografting degree of 85.28% and the highest amidoxime group density of 4.38 mol/kg. The field study was performed along the coastal area of the Gulf of Thailand. After 56 days of soaking, the highest adsorption capacity reached 1.79 g-U/kg-adsorbent. The reusability study for up to 6 cycles revealed about 20% of the adsorption capacity remaining in the last cycle. The study demonstrated that recycled LDPE sheets can be utilized as a substrate to synthesize uranium absorbers. It showed an acceptable uranium loading with good reusability in natural seawater environment. This method of reusing discarded LDPE sheets also helps alleviate environmental issues of non-degradable plastic wastes.

Preparation and Stabilization of High Molecular Weight Poly (acrylonitrile-co-2-methylenesuccinamic acid) for Carbon Fiber Precursor.

Bifunctional comonomer 2-methylenesuccinamic acid (MLA) was designed and synthesized to prepare acrylonitrile copolymer P (AN-co-MLA) using mixed solvent polymerization as a carbon fiber precursor. The effect of monomer feed ratios on the structure and stabilization were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), X-ray diffraction (XRD), proton nuclear magnetic (1H NMR), and differential scanning calorimetry (DSC) for the P (AN-co-MLA) copolymers. The results indicated that both the conversion and molecular weight of polymerization reduce gradually when the MLA content is increased in the feed and that bifunctional comonomer MLA possesses a larger reactivity ratio than acrylonitrile (AN). P (AN-co-MLA) shows improved stabilization compared to the PAN homopolymer and poly (acrylonitrile-acrylic acid-methacrylic acid) [P (AN-AA-MA)], showing features such as lower initiation temperature, smaller cyclic activation energy, wider exothermic peak, and a larger stabilization degree, which are due to the ionic cyclization reaction initiated by MLA, confirming that the as-prepared P (AN-co-MLA) is the potential precursor for high-performance carbon fiber.

Development of a Fibrous Adsorbent Prepared Via Green Vapor-Phase Grafting Polymerization for Uranium Extraction.

Owing to many problems of the detriment by large amount of organic reagents, high cost and difficulty of industrialization, development of high-efficiency economical technologies for uranium extraction is an irresistible trend to support steady supply of nuclear energy. Herein, a novel fibrous adsorbent, named as AO-HPE fibers, was prepared by introduction of amidoxime groups using the green vapor-phase grafting polymerization (VPGP) technology of monomer acrylonitrile (AN). Gaseous AN was grafted onto the ultra high molecular weight polyethylene (UHMWPE) fibers at 80 °C in the enclosed evaporation and condensation reflux system. The innovative technology not only endowed synthetic process high monomer utilization ratio but also excellent environmental friendliness. The AO-HPE fibers exhibited an appreciable calculated maximum adsorption capacity (Qm) of 1144.94 mg·g–1 in uranium solution and an adsorption capacity of 14.11 mg·g–1 in simulated seawater. Meanwhile, the higher uranium selectivity than main competing ion vanadium (adsorption mass ratio was almost 5) was achieved. The adsorption process accorded closely with chemisorption mechanism. This work provided a novel idea for the synthetic method of adsorbents for uranium extraction, and inspired the sustainable technologies for grafting polymerization of monomer AN.

Homogeneous and heterogeneous atmospheric ozonolysis of acrylonitrile on the mineral dust aerosols surface

Acrylonitrile (ACN) is a highly toxic substance that exists widely in the environment. It can pollute the environment and endanger human health. VOCs prone to nucleation and heterogeneous reaction on the mineral dust aerosols surface. Based on the DFT calculation, the ozonolysis processes of ACN in homogeneous reactions, heterogeneous reactions on SixOy(OH)z clusters surface and heterogeneous reactions on (Al2O3)n clusters surface were studied in this paper. Ozone addition was the rate-determining step for ozonolysis of ACN with the rate constant of 2.03 × 10−18 cm3 molecule−1 s−1 at 298 K and 1 atm. Toxicity assessment showed that ozonolysis degradation effectively reduced the ecotoxicity of ACN. In this study, six kinds of non-metallic oxides SixOy(OH)z clusters and thirteen kinds of metal oxides (Al2O3)n clusters were selected to simulate the adsorption behavior of ACN adsorbed on different mineral dust aerosols surface. ACN-SixOy(OH)z cluster polymers formed hydrogen bond interactions, while ACN-(Al2O3)n cluster polymers mainly formed metallic bonds (Al-N), and they also had hydrogen bond interactions. The adsorption of SixOy(OH)z clusters and (Al2O3)n clusters did not change the reaction mechanisms for ozonolysis of ACN, but affected the reaction rate constant to varying degrees. In addition, it was found that the adsorption modes of mineral dust aerosols surface had no correlation with the rate constants for ozonolysis of ACN.

Experimental and Computational Studies on the Reactivity of Methanimine Radical Cation (H2CNH+•) and its Isomer Aminomethylene (HCNH2+•) With C2H2

Experimental and theoretical studies are presented on the reactivity of the radical cation isomers H2CNH+• (methanimine) and HCNH2+• (aminomethylene) with ethyne (C2H2). Selective isomer generation is performed via dissociative photoionization of suitable neutral precursors as well as via direct photoionization of methanimine. Reactive cross sections (in absolute scales) and product branching ratios are measured as a function of photon and collision energies. Differences between isomers’ reactivity are discussed in light of ab-initio calculations of reaction mechanisms. The major channels, for both isomers, are due to H atom elimination from covalently bound adducts to give [C3NH4]+. Theoretical calculations show that while for the reaction of HCNH2+• with acetylene any of the three lowest energy [C3NH4]+ isomers can form via barrierless and exothermic pathways, for the H2CNH+• reagent the only barrierless pathway is the one leading to the production of protonated vinyl cyanide (CH2CHCNH+), a prototypical branched nitrile species that has been proposed as a likely intermediate in star forming regions and in the atmosphere of Titan. The astrochemical implications of the results are briefly addressed.

Density functional theory study of lignin, carboxymethylcellulose and unsustainable binders with graphene for electrodes in lithium-ion batteries

Electrodes are the fundamental components in lithium-ion batteries to develop high-performance device systems. The fabrication process of electrodes involves a mixing of active materials, a nonconductive polymeric binder material, and an electrically conductive additive. Binders play a critical role during the electrochemical process, which tightly holds the active materials together within the electrode to provide a long-cycle life. The present study investigates the strength of the interaction for different binders such as vinylidene fluoride (VDF), pyrrole (PY), styrene-butadiene (SB), acrylonitrile (AN), tetrafluoroethylene (TFE), carboxymethylcellulose (CMC), and lignin monomers, coumarylalcohol (LCmA), coniferylalcohol (LCnA), and sinapylalcohol (LSiA), using density functional theory calculations. The result reveals that sustainable binders (CMC, LCmA, LiCnA, and LSiA) exhibit higher interaction energy than unsustainable binders (VDF, PY, SB, AN, and TFE). The highest interaction energy is obtained for the graphene-LiSiA system, followed by graphene-LCnA and graphene-LCmA. Comparing the orientation of the binders on the graphene surface, all binders make a face-to-face arrangement with graphene. This interaction is greatly enhanced for those binders that possess aromatic rings with functional groups (methoxy and hydroxyl). These results provide significant insights for the use of lignocellulosic biomass materials such as lignin and cellulose as binders in energy devices toward more sustainability.

Radiation Graft-Copolymerization of Ultrafine Fully Vulcanized Powdered Natural Rubber: Effects of Styrene and Acrylonitrile Contents on Thermal Stability.

Graft copolymers, deproteinized natural rubber-graft-polystyrene (DPNR-g-PS) and deproteinized natural rubber-graft-polyacrylonitrile (DPNR-g-PAN), were prepared by the grafting of styrene (St) or acrylonitrile (AN) monomers onto DPNR latex via emulsion copolymerization. Then, ultrafine fully vulcanized powdered natural rubbers (UFPNRs) were produced by electron beam irradiation of the graft copolymers in the presence of di-trimethylolpropane tetra-acrylate (DTMPTA) as a crosslinking agent and, subsequently, a fast spray drying process. The effects of St or AN monomer contents and the radiation doses on the chemical structure, thermal stability, and physical properties of the graft copolymers and UFPNRs were investigated. The results showed that solvent resistance and grafting efficiency of DPNR-g-PS and DPNR-g-PAN were enhanced with increasing monomer content. SEM morphology of the UFPNRs showed separated and much less agglomerated particles with an average size about 6 μm. Therefore, it is possible that the developed UFPNRs grafted copolymers with good solvent resistance and rather high thermal stability can be used easily as toughening modifiers for polymers and their composites.

Regulating lithium deposition via electropolymerization of acrylonitrile in rechargeable lithium metal batteries

We report acrylonitrile (AN) as an effective additive in carbonate-based electrolytes to enable uniform and dense lithium (Li) deposition and to improve the coulombic efficiency of Li metal anode. Our electrochemical, spectroscopic, and theoretical study reveal that AN is cathodically electropolymerized on the Li surface prior to the electrochemical decomposition of the electrolyte during Li deposition. The resultant polyacrylonitrile artificial solid electrolyte interphase enables uniform nucleation and growth of Li deposition with significantly reduced side reactions. The effectiveness of the AN additive is demonstrated in 0.4 Ah Li||LiNi 0.6 Mn 0.2 Co 0.2 O 2 pouch cells (using 50-μm Li anode, 3 mAh cm −2 cathode areal capacity, and 4 g Ah −1 electrolyte) with excellent cycle stability under realistic charge-discharge condition. • Acrylonitrile is revealed as an excellent electrolyte additive for lithium metal rechargeable batteries. • Polyacrylonitrile solid electrolyte interphase via electropolymerization improves the properties of lithium plating-stripping. • Excellent battery performance in 0.4Ah Li||LiNi 0.6 Mn 0.2 Co 0.2 O 2 pouch cells using crylonitrile additive is demonstrated.

Structure and properties of heat-resistant ABS resins innovated via MSAMI random copolymer

This work proposed an efficient method to synthesize acrylonitrile-butadiene-styrene (ABS) copolymer and α-Methylstyrene (α-MSt)/N-phenylmaleimide (NPMI)/Acrylonitrile (AN) (MSAMI) random copolymer via emulsion polymerization, aiming to combine the excellent heat resistance of MSAMI and numerous advantages of ABS resin including mechanical properties, processing and recyclability. The effects of the MSAMI content and α-MSt/AN ratio on the thermal performance, mechanical properties and the morphology of heat-resistant ABS were investigated by FITR, dynamic mechanical analyses (DMA), Vicat Softening Temperature (VST), Thermogravimetric Analysis (TGA) and Scanning Electron Microscope (SEM). As a result, the heat-resistant of ABS resin was obviously enhanced by MSAMI, and its glass transition temperature (Tg) could be extended with the increase of NPMI content. The Tg could reach 173°C when NPMI content was 20% at the same trend as the VST. Synthetically, the contradiction between the heat resistance and mechanical properties of ABS resin reached a good balance when the NPMI content was 15% and α-MSt/AN ratio was 69/31. In SEM, the fracture morphology of the heat-resistant ABS resin was gradually tended to be smooth with the increase of the NPMI content. Therefore, the MSAMI random copolymer was successful prepared, which provided insight for the synthesis of heat-resistant modifiers and promoted the potential application of heat-resistant modifiers in automobiles and aircraft.

Preparation and Properties of Thermally Expandable Microspheres for Foam Coating

A type of thermally expandable microspheres (TEMs) for foam coating was prepared by suspension polymerization with acrylonitrile (AN), methyl methacrylate (MMA), vinyl acetate (VAC) as shell polymer monomers and i-pentane as core foaming agent. The effects of an aqueous additive (Sodium Chloride, NaCl) on the size and distribution of TEMs, and the effects of crosslinking degree, i-pentane dosage and monomer mass ratio on the expansion property, expansion temperature and solvent-resistance of TEMs were investigated. The results showed that when the dosage of NaCl was close to the saturation solubility (30%), the dosage of crosslinking agent and alkane were about 0.09% and 7.4%, and the mass ratio of AN/MMA/VAC w rm distribution and good solvent resistance, the expansion diameter ratio was 5 times under 110~120 C, which meets the application requirements for foam coating of leather or synthetic leather.

Graft Copolymerization of Acrylonitrile onto Sodium Salt of Partially Carboxymethylated Tamarind Kernel Powder Using Ceric Ammonium Nitrate as a Photo‐Initiator in an Aqueous Medium Under Ultraviolet‐Radiation

AbstractUltraviolet (UV) radiation‐induced graft copolymerization of acrylonitrile (AN) onto sodium salt of partially carboxymethylated tamarind kernel powder (Na‐PCMTKP, ) has been carried out using ceric ammonium nitrate (CAN) as a photo‐initiator. The optimal UV‐radiation‐induced grafting conditions have been established with Na‐PCMTKP = 0.5 g (dry basis), [HNO3] = 0.2 mol L−1, [AN] = 0.295 mol L−1, [CAN] = 6.0 × 10−3 mol L−1, time = 6 h, temperature = 30 °C, volume of water = 144.58 mL, and total volume = 150 mL. The maximum percentage of grafting (%G) and percentage grafting efficiency (%GE) achieved under these established optimum reaction conditions are 361.16% and 89.33%, respectively. The various reaction conditions have been varied with a view to study their influence on the grafting yields (%G and %GE). A plausible mechanism to explain initiation, propagation, and termination of UV‐radiation‐initiated graft copolymerization has also been suggested. The influence of the efficiency of the photo‐initiator on the grafting yields has been investigated. Fourier transform infrared, thermogravimetric analysis, differential scanning calorimeter (DSC), and scanning electron microscopy techniques have been successfully used to provide the evidence of grafting of polyacrylonitrile onto Na‐PCMTKP. The kinetics of thermal decomposition of the graft copolymer, Na‐PCMTKP‐g‐PAN, has also been investigated with the help of the DSC curves obtained at different heating rates. The Ozawa and the Kissinger methods have been utilized for the evaluation of the kinetic parameters for the thermal decomposition of the graft copolymer sample. The synthesized graft copolymer after saponification may be used as a superabsorbent hydrogel for potential applications.