Preparation and Characterization of Carboxyl-terminated Poly(butadiene-co-acrylonitrile)-epoxy Resin Prepolymers for Fusion-bonded-epoxy Powder Coating

Liquid carboxyl-terminated poly（butadiene-co-acrylonitrile）（CTBN）-epoxy resin（EP） prepolymers were prepared with different contents of CTBN.The chemical reactions between EP and CTBN were characterized by Fourier ransform infrared（FTIR） spectroscopy and gel permeation chromatography（GPC）.The scanning electron micrograph（SEM） and dynamic mechanical analysis（DMA） of curing films showed phase separation,and the rubber particles were finely dispersed in the epoxy matrix.Mechanical properties analysis of curing films showed that impact strength and elongation at break increased significantly upon the addition of CTBN,indicating good toughness of the modified epoxy resins.Thermogravimetric analysis（TGA） showed that the incorporation of CTBN had little effect on the thermal stability of EP.Fusion-bonded-epoxy（FBE） powder coatings modified with CTBN-EP prepolymers were prepared.The experimental results demonstrate the ability of CTBN-EP prepolymers,toughening technology to dramatically enhance the flexibility and impact resistance of FBE coatings without compromising other key properties such as corrosion protection.

Synthesis and characterization of miktoarm star copolymer of styrene and butadiene using multifunctional macromolecular initiator

A new kind of multifunctional macromolecular initiator with Sn-C bonds and polydiene arms was synthesized by living anionic polymerization. At first, polydiene-stannum chloride （PD-SnCl3） was prepared by the reaction of n-butyl-Li （n-BuLi）, stannic chloride （SnCl4） and diene. Then PD-SnCl3 was used to react with the dilithium initiator to prepare the multifunctional organic macromolecular initiators. The result suggested that the initiators had a remarkable yield by GPC, nearly 90%. By using these multifunctional macromolecular initiators, styrene and butadiene were effectively polymefized via anionic polymerization, which gave birth to novel miktoarm star copolymers. The relative molecular weight and polydispersity index, microstructure contents, copolymerization components, glass transition temperature （Tg） and morphology of the miktoarm star copolymers were investigated by GPC-UV, ~H NMR, DSC and TEM, respectively. 2009 Xing Ying Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Synthesis of polystyrene-styrene/butadiene diblock copolymers via reversible addition-fragmentation chain transfer miniemulsion polymerization

Polystyrene-styrene/butadiene diblock copolymers were synthesized via reversible addition-fragmentation chain transfer （RAFT） miniemulsion polymerization.During the polymerization process,the molecular weight distribution was narrow and the numerical molecular weight of the copolymers increased with increasing conversion of monomers,which was close to the theoretical.FT-IR and ^1H NMR results indicated that the microstructure of the polymer was mainly 1,4-trans-butadiene with small amount of 1,2-units,and composition in the copolymers was obtained.

IN SITU MONITORING OF COORDINATION COPOLYMERIZATION OF BUTADIENE AND ISOPRENE VIA ATR-FTIR SPECTROSCOPY

FTIR spectroscopy in combination with a diamond tipped attenuated total reflectance （ATR） immersion probe was utilized to study in situ the copolymerization of butadiene （Bd） and isoprene （Ip） with neodymium-based catalyst in hexane. The relationship between the signal intensity of monomer and its concentration was investigated. The kinetic study of copolymerization of Bd and Ip was further conducted, and the monomer reactivity ratios were determined via in situ ATR FTIR. The signal band at 1010 cm^-1 was assigned to wagging vibration of Bd and its intensity was proportional to Bd concentration （[Bd]） in the range of 0.46-3.88 mol.L^-1. The signal bands at 890 and 989 cm^-1 were assigned to wagging vibration of Ip and the signal intensity was also proportional to Ip concentration （[Ip]） in the range of 0.08-4.73 mol·L^-1 at 890 cm^-1 and 0.08-7.49 mol·L^-1 at 989 cm^-1, respectively. Thus the signal band at 1010 cm^-1 was chosen to monitor Bd concentration and bands at 989 and 890 cm^-1 to monitor Ip concentration during the copolymerization, respectively. It was demonstrated that the conversions of Bd and Ip calculated from FTIR data agreed very well with those obtained gravimetrically. The poiymerization rates were first order with respect to both [Bd] and [Ip], respectively at different polymerization temperatures. The apparent propagation activation energy for Bd and Ip could be determined to be 54.4 kJ·mol^-1 and 57.7 kJ·mol^-1, respectively. The monomer reactivity ratios were calculated to be 1.08 for Bd （rBd） and 0.48 for IP （rIp） based on FTIR data. The Bd-Ip copolymer products with random sequence could be obtained with only one glass transition temperature.

Computational Study on the Hetero-Diels-Alder Reactions between Phosphonodithioformate and Butadienes

The mechanism, catalytic effect and substituent effect of the hetero-Diels-Alder reactions between phosphonodithioformate and butadienes have been investigated theoretically using density functional theory at the B3LYP/6-31G（d） level. The results show that all of these reactions proceed in a concerted but asynchronous way. In some reactions the formation of C-S bond is prior to that of C-C and opposite result is found in other reactions. The BF3 catalyst and trimethylsilyloxy group may lower the activation barriers by changing the energies of FMOs for reactant molecules. With the BF3-catalyzed reactions, the complete regioselectivity observed experimentally has well been reproduced by theoretical calculation and these results originate probably from blue-shifting C-H...F hydrogen bond interaction in some transition states.

Performance of CTBN(carboxyl-terminated poly (butadiene-co-acrylonitrile))-EP(diglycidyl ether of bisphenol-A (DGEBA)) Prepolymers and CTBN-EP/polyetheramine (PEA) System

CTBN-EP prepolymers were synthesized from CTBN and epoxy resin under the catalysis of HTMAB. FTIR analyses indicate the formation of ester group between the carboxyl group of CTBN and the oxirane group of epoxy resin. The viscosity of modified prepolymer increases with CTBN content increasing, but the epoxy value of the prepolymer decreases greatly. DSC analyses verify that CTBN affects the curing process of CTBN-EP/PEA system. Mechanical testing presents the improved toughness of CTBN-EP/PEA curings for the decrease of tensile strength, flexural strength and compressive strength, and increase of impact strength and elongation-at-break with the CTBN content increasing. SEM micrographs show the rubber phase with many holes in diameter about 0.5-1.5 μm is formed when CTBN content is lower than 10 phr. However, the pattern of SEM graph shows some stalactite-like strips when CTBN content is higher than 15 phr. Furthermore, the SEM image of 25 phr CTBN sample forms a kind of co-continuous structure.

CHARACTERIZATION OF IRON COMPLEXES SUPPORTED ON POLYMER AND THEIR CATALYTIC ACTIVITY IN BUTADIENE POLYMERIZATION

Styrene-acrylic acid copolymer (SAAC)-supported iron complex (SAAC·Fe)was characterized and the effect of the characteristic parameters on the catalytic activity of the complex was investigated. IR spectrum suggested that the complex SAAC·Fe possesses a structure of(C)and the Fe-O bond is higher in covalency.The complex SAAC·Fe with the structure of(C)shoved a higher catalytic activity in butadiene polymerization. When Fe/-COOH molar ratio in SAAC·Fe was about 0.2 the complex gave optimum catalytic activity. The catalytic activity of SAAC·Fe with the higher content of long sequence of acrylic acid units was low. When the content of the short sequence of acrylic acid units was predominant and at the same time the content of the short sequence was approximately equal to that of the long sequence for stryrene, the activity of the complex was high.

Coordinative chain transfer copolymerization of 1,3-butadiene and isoprene by neodymium precatalyst

Coordinative chain transfer polymerization(CCTP)is a newly developed strategy that features similarly,but superiorly,to classical living polymerization,in other words,precise molecular weight controlling,narrow molecular weight distribution,atom economy and so on,and has been quickly grown as a powerful tool to prepare the target polymer materials[1].As an extension of this concept,the present study discloses our recent progresses on CCTP of butadiene(Bd)and isoprene(Ip)to prepare precisely controlled Bd/Ip copolymers.

Comparison between Pigment Printing Systems with Acrylate and Butadiene Based Binders

Pigment printing was carried out on lab scale by simple screen-printing techniques. By the application of acrylate and butadiene based binder, the crocking fastness, formaldehyde release and PVC migration of fabric printed with Imparon red KB pigment was evaluated. The effect of curing time on K/S values was also investigated. It has been found that butadiene based binder shows good performance in terms of crocking fastness, formaldehyde release and PVC migra-tion. It has also been observed that by increasing the binder concentration, the release of formaldehyde decreased and by increasing the curing time, the K/S values of printed fabric were decreased.

The Effects of Build Parameters and Strain Rate on the Mechanical Properties of FDM 3D-Printed Acrylonitrile Butadiene Styrene

In this paper, the effects of build parameters on the mechanical properties of 3D-printed acrylonitrile butadiene styrene (ABS) produced using fused deposition modeling (FDM) are investigated. Full factorial experimental design incorporating a 2-level, 3-factor design with raster angle, layer thickness and interior fill style was carried out. Tensile tests were performed at four different strain rates to determine how the build parameters influence the mechanical properties of the 3-D printed ABS and to assess its strain rate sensitivity under quasi-static loading. It was found that the modulus of toughness of ABS material is most influenced by raster angle, while the interior fill style is the most dominant build parameter that dictates the specimen’s modulus of resilience, yield strength and ultimate tensile strength. At all strain rates, it is further revealed that higher mean values of yield strength, ultimate tensile strength and modulus of resilience were obtained when the interior fill style is solid as opposed to high density. This can be attributed to the denser structure and higher effective cross-sectional area in solid interior fill style in comparison with high density interior fill style. However, the influence of the layer thickness on the investigated mechanical properties was found to be inconsistent. It was noted that specimens built with both 0.254 mm layer thickness and the cross [0°/90°] raster angle had superior mechanical properties when compared to those built with the 0.3302 mm layer thickness and cross [0°/90°] raster angle. This suggests that there is a key interaction between the layer thickness and the raster angle. At any FDM build parameter, it was found that all the mechanical properties investigated in this work exhibited modest sensitivity to strain rates. This study has provided a platform for an appropriate selection of build parameters combinations and strain rates for additive manufacturing of 3D-printed ABS with improved mechanical properties.

Study of Mechanical and Physical Properties of Palm Fiber Reinforced Acrylonitrile Butadiene Styrene Composite

Palm fiber (PF) reinforced acrylonitrile butadiene styrene (ABS) composite matrix was prepared by employing Injection Moulding Machine (IMM). Palm fiber was collected from ten different trees of different age group from Comilla region in Bangladesh. Three sets of samples were prepared for three different wt% (5%, 10% and 20%) of fiber contents. The mechanical (tensile strength, flexural stress, micro hardness, Leeb’s rebound hardness) and physical (bulk density and water absorption) properties were measured. The observed result reveals that the tensile strength (TS) and flexural stress (FS) were decreased with increasing fiber contents in the PF-ABS composites except 10% fiber content.

SOME THEORETICAL PROBLEMS OF ANIONIC POLYMERIZATION OF BUTADIENE——A Study on the Association Degree of n-BuLi and Polybutadienyl-Li

This paper determined the association degree of n-BuLi and polybutadinyllithium(PBLi)by UV spec-trometry and viscometry.The experimental results of UV spectrometric analysis showed that the associationdegree of n-BuLi as well as PBLi is dependent mainly on their concentration in solutions;there may be specieswith three and two degrees of association in cyclohexane solvent respectively for n-BuLi and PBLi,i.e.the asso-ciation degree for the former is equal to 2,4 and 6;and for the latter it equals to 2 and 4.Similarly,the experi-mental results obtained by viscometric measurement showed that the average association degree N of PBLiin cyclohexane changed from 2 to 4 with increasing of its concentration in solution and decreased with addi-tion of a small amount of polar additive into the above mentioned system.Furthermore,in pure polar solvent,such as dimethoxyethane(DME),tetrahydrofuran(THF)or dioxane(DOX),PBLi is completely dissociatedinto monomeric species;however,in pure diethyl ether,due to its weak polarity a part of associated species stillcan be found.Generally speaking,all of the above results were consistent with the results of kinetic studies in-vestigated by us before.

Influence of Poly(methylmethacrylate) Dopant on Butadiene Derivative Electroluminescence

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POLYMER-SUPPORTED LANTHANIDE COMPLEXES FOR THE POLYMERIZATION OF BUTADIENE

The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes (SAAC Ln) (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, and Lu) were described. A comparison of the activities of SAAC·Ln was made. It was found that in the polymerization of butadiene, a peak in activity appeared at Nd and Pr, Sin, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1, 4 polybutadiene attained was more than 98%.

STUDY ON STYRENE-BUTADIENE BLOCK COPOLYMER FOR THE MODIFICATI0N OF TIRE TREAD

This paper mainly deals with the design and synthesis of a novel styrene-butadieneblock copolymer. When this copolymer is used in the tread portion of tyres, it can improvewet skid resistance and reduce rolling resistance without sacrificing its general physical-mechanical properties. The visco-elastic curve of tire tread using the novel copolymer asits rubber portion was showed. Reactivity ratios for two monomers in the polymerizingsystem were calculated. The diagrams of differelitial, integral and finite difference calculithroughout the whole molecular chain were presented. The influence of the micro- andmacro-structure of the copolymer chain on wet skid resistance and rolling resistance wasdiscussed

Copolymerization of Butadiene and Isoprene by NdC_6H_6(AlCl_4)_3-AlR_3 System

This paper reported the copolymerization results of butadiene and isoprene catalyzed by NdC_6H_6(AlCl_4)_3-AlR_3 system.The results show that the catalytic activity is dependent on the weight ratio of butadiene and isoprene,the concentration of comonomers,the nature of alkylaluminium and the polymerization temperature as well.High contents of 1,4 microstructure of copolymer are obtained by the novel catalyst system.

An Additional 100 kt/a Butadiene Production Line Constructed by Yangzi Petrochemical Company

A 0.1 Mt/a butadiene production line(hereinafter abbreviated as the third butadiene unit) constructed at the SINOPEC Yangzi Petrochemical Company had passed acceptance tests in August 2009.The Yangzi Petrochemical’s third butadiene unit consists of the main unit,the storage facilities

Synthesis Mediated by Zirconium, Crystal Structure and Theoretical Studies on Six-substituted Benzene with Silalactone Structure and Butadiene Derivative

A novel method for the synthesis of novel silalactone was proposed by iodation and zirconium-mediated cycloaddition of alkynes. 1,1-Dimethyl-4-carboxylatethyl-6,7-diphenyl-5-（trimethylsilyl）-1,3-dihydrobenzo[c][1,2]oxasilol-3（1 H）-one（compound 1） was obtained and characterized by X-ray single-crystal diffraction. It belongs to the monoclinic system, space group P2_1/n with a = 12.706（3）, b = 10.826（2）, c = 19.407（4） A, β = 91.50（3）°, V = 2668.4（9） A^3, Z = 4, F（000） = 1004, D_c = 1.182 mg/m^3, μ = 0.162 mm^-1, T = 293（2） K, S = 1.129, R = 0.0868 and wR = 0.1607 for 3542 observed reflections with I 〉 2σ（I）. The butadiene derivative, 3,6-di（2-methylphenyl）-4,5-diethylocta-3,5-diene（compound 2）, was synthesized by zirconacyclopentadiene and aryl iodides in the presence of Cu Cl and Pd（PPh3）4. It was characterized by X-ray single-crystal diffraction for the first time, belonging to the monoclinic system, space group C2/c with a = 19.015（4）, b = 7.7697（16）, c = 15.298（3） A, β = 98.24（3）°, V = 2236.8（8） A^3, Z = 8, F（000） = 760, D_c = 1.029 mg/m^3, μ = 0.057 mm^-1, T = 293（2） K, S = 1.100, R = 0.0673 and wR = 0.1391 for 1302 observed reflections with I 〉 2σ（I）.

Study on the Effect of Carboxyl Terminated Butadiene Acrylonitrile (CTBN) Copolymer Concentration on the Decomposition Kinetics Parameters of Blends of Glycidyl Epoxy and Non-Glycidyl Epoxy Resin

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.

Effect of nitrile butadiene rubber hardness on the sealing characteristics of hydraulic O-ring rod seals

The nitrile butadiene rubber(NBR)hardness effect on the sealing characteristics of hydraulic O-ring rod seals is analyzed based on a mixed lubrication elastohydrodynamic model.Parameterized studies are conducted to reveal the mechanism of the influence of rubber hardness on the static and dynamic behavior of seals.The optimized selections of rubber hardness are then investigated under different conditions.Results show that the low hardness seal is prone to stress concentration due to the extrusion effect under high pressure conditions;it is also more prone to leaking.A high hardness seal can better prevent leakage by reducing film thickness but it will cause large frictional power loss and increase the probability of wear failure.The choice of low hardness is recommended to reduce friction with the premise that leakage requirements are met.