Synthesis and Radical Copolymerization of Ethyl Acrylate and Butyl Acrylate with N-[4-N'-(Phenylamino-carbonyl) phenyl] maleimide

Radical copolymerization of ethyl acrylate (EA) and butyl acrylate (BA) with 4-maleimidobenzanilide (MB), that is N-[4-N′-(phenylaminocarbonyl)phenyl]maleimide, initiated by AIBN was performed in THF solvent at 65°C. Nine copolymer samples of each type were prepared using different feed ratios of comonomers. All the polymer samples have been characterized by solubility test, intrinsic viscosity measurements, FT-IR and ¹H-NMR spectral analysis, and thermo-gravimetric analysis. The values of monomer reactivity ratios r₁ and r₂ are 1.13 and 0.48 in MB/EA system and 0.45 and 0.52 MB/BA system. Alfrey-Price Q-e values for MB were Q = 1.31 and e = 1.33 in MB/EA and Q = 2.04 and e = 2.06 in MB/BA systems. The initial decomposition temperature of copolymer samples were in the range 310 to 365°C.     

Effects of poly(methyl methacrylate-co-n-butyl acrylate) on the properties and processing behavior of poly(vinyl chloride)

Random copolymers of methyl methacrylate/n-butyl acrylate with a BA content of 0–50% and M?_v = 0.16–4.04 × 10⁶ were synthesized and evaluated as a processing aid (PA) for poly(vinyl chloride) (PVC). Their effects on the processability and properties of PVC were investigated with respect to the composition, molecular weight, and the amount of the copolymer added. It was found that the fusion rate of PVC could be improved (i) by increasing the amount of the copolymer used, (ii) by increasing the butyl acrylate content in the copolymer, and (iii) by lowering the molecular weight of the copolymer. The effect of molecular weight, composition, and amount of copolymer on the ultimate mechanical properties of PVC was investigated. The presence of copolymer did not affect the impact strength. However, the tensile strength and elongation at break were improved, particularly at high temperature (125°C). It was also found that the “plate out” phenomenon of PVC could be significantly reduced in the presence of the processing aid.     

Synthesis and water absorbency of the copolymer of acrylamide with anionic monomers

A series of novel copolymer superabsorbents based on acrylamide, sodium allylsulfonate, sodium acrylate, and N,N′-methylenebisacrylamide were prepared by copolymerization. The resulting superabsorbents have a fast swelling rate. The experimental results show that absorbency increases to a maximum as the cross-linking increases, but an excess of cross-linking leads to a swelling decrease. Their water retention was observed at pressures of 1–10 kg/cm² and temperatures of 60 and 100°C, respectively. The water retention of soil has been enhanced by using the poly(acrylamide–sodium allysulfonate–sodium acrylate) superabsorbent; its use for bean growth was also investigated. © 1994 John Wiley & Sons, Inc.     

Calculation of reactivity ratios of methacrylic acid-ethyl acrylate copolymer by on-line quantitative 1H NMR spectroscopy

The solution copolymerization of methacrylic acid (MAA) and ethyl acrylate (EA) was studied by online proton nuclear magnetic resonance spectroscopy (¹H NMR) using 2,2′–azobisisobutyronitrile as an initiator in deuterated dimethyl sulfoxide at 60 °C. The chemical compositions of the copolymer and the comonomer concentrations were determined from the conversion of comonomers to copolymer by quantitative in situ NMR monitoring to estimate the reactivity ratios of the comonomers at low conversion. This is a new and easy methodology to analyze radical copolymerization. In this research, it is shown that monomer reactivity ratios can be calculated by data collected only from one initial comonomer mixture composition via online monitoring progress of the copolymerization reaction. The reactivity ratios of MAA and EA are equal to 2.360 and 0.414, respectively. This approach is used to compute the monomer reactivity ratios in a nonlinear integrated form of the copolymerization equation which is described by Mayo and Lewis terminal model. The fairly good agreement between the results and the literature data reported for the emulsion system represent the accuracy of the reactivity ratios calculated by this new approach. The calculated reactivity ratios for emulsion copolymerization are r _MAA = 2.040 and r _EA = 0.470, and the previous literature data are r _MAA = 2.580 and r _EA = 0.157.     

明胶代用物AN—BA共聚物的合成和应用

用乳液聚合法合成的丙烯酸丁酯-丙烯腈共聚物是一种性能优良的明胶代用物,而采用无机—有机复合乳液聚合技术合成的含硅的丙烯腈-丙烯酸丁酯共聚物乳液,作为明胶代用物,不仅保留原共聚物的性能,又有良好的渗透性,可改善胶片的照相性能,适用于高温快显机器加工的照片。     

Novel cross-linked membranes based on polybenzoxazine and polybenzimidazole containing 4-phenyl phthalazinone moiety for high-temperature proton exchange membrane

Here, we report a series of novel PA-doped cross-linked benzoxazine-polybenzimidazole copolymer membranes. These membranes were obtained by mixing PBI containing 4-phenyl phthalazinone moieties (PPBI) and 4-phenyl phthalazinone-based benzoxazine (Bp) in N-methyl pyrrolidone (NMP), followed by heating to 260 °C. The cross-linking reaction was determined by DSC and gel fraction tests. These copolymer membranes showed excellent comprehensive properties, with high proton conductivity up to 14.7 mS/cm at 160 °C under anhydrous conditions. Besides, the P(PBp-co-PPBI)-30 membrane exhibited excellent mechanical property (approximately 50% improvement in tensile modules and strength compared to the pristine PPBI) and oxidative stability in Fenton’s test (remaining intact after 226 h). This study proved that using benzoxazine as a cross-linking agent is a promising method for improving the properties of proton exchange membranes (PEMs).     

Graft Copolymerization of Chitosan with Butyl Acrylate and Application of the Copolymers to Cotton Fabric

Graft polymerization of butyl acrylate (BuA) onto chitosan using potassium persulfate (KPS) as initiator was studied under different conditions. The grafting percentage (G%) and the grafting efficiency (GE%) increase by increasing KPS concentration up to 40 mmol/L then decrease thereafter. Another trend was observed with BuA concentration where G% increases significantly as BuA concentration increases within the range studied, i.e., 10%–100%, based on weight of chitosan sample (ows), meanwhile GE% exhibits a maximum at BuA concentration of 50% ows. Temperature acts in favor of grafting up to 65°C where maxima for both G% and GE% could be achieved. The grafting reaction is characterized by an initial fast rate during the first 60 minutes then levels off thereafter. Poly (BuA)-chitosan graft copolymers were applied to cotton fabric in presence and absence of low formaldehyde cross-linking agent. Introduction of the copolymer and the cross-linking agent to cotton fabric enhances the performance of the latter to a great extent provided that the copolymer and the cross-linking agent are applied in two subsequent steps. Fabric performance was assessed through monitoring, nitrogen content, crease recovery angle, tensile strength and elongation at break.     

Preparation of damping structural integration materials via the formation of nanostructure in triblock copolymer modified epoxy resins

Amphiphilic triblock copolymer Poly(ε-caprolactone)-block-polydimethylsiloxane-block-poly(ε-caprolactone) (PCL-b-PDMS-b-PCL, LDL) was synthesized via the ring-opening polymerization of ε-caprolactone in the presence of hydroxyl-terminated polydimethylsiloxane (HTPDMS) and was utilized to modify epoxy. The tensile strength and elongation at break were simultaneously enhanced when the triblock copolymer was incorporated. With increasing the concentration of the triblock copolymer, the damping temperature range (tanδ >0.25) was broadened from 21 °C to 34.5 °C. Meanwhile, the storage modulus of the composites and the values of tanδ had no significant decrease. When the concentration of the triblock copolymer was 20 wt%, the value of K_IC attained 1.68 MN/m^3/2, which was 1.56 times that of the neat epoxy (1.08 MN/m^3/2). Besides, the characterization of hydrophobic and hydrophilic performance indicated that the incorporation of the triblock copolymer made epoxy resins transformed from hydrophilic to hydrophobic. It is expected that damping composites obtained by this method may be used as damping structural integration materials in future.     

Copolymerization of Methyl Methacrylate,Ethyl Acrylate,and Butyl Acrylate with N-2-Anisylmaleimide and Characterization of the Copolymers

The free radical copolymerizations of methyl methacrylate (MMA), ethyl acrylate (EA), and butyl acrylate (BA) with N-2-Anisylmaleimide (AMI), initiated by AIBN, were performed in THF solvent at 65°C. A series of copolymers of AMI-MMA, AMI-EA, and AMI-BA were prepared using different feed ratios of comonomers. The polymer samples have been characterized by solubility tests, intrinsic viscosity measurements, FT-IR, and ¹H-NMR spectral analysis, and thermo-gravimetric analysis. The values of monomer reactivity ratios r₁ and r₂ determined by Fineman-Ross and Kelen-Tudos methods are 0.43 and 0.42 in AMI/MMA, 0.72 and 0.62 in AMI/EA and 0.76 and 0.72 in AMI/BA systems. Alfrey-Price Q-e values for AMI are Q = 3.13 and e = 1.71 in AMI/MMA, Q = 1.10 and e = 1.46 in AMI/EA and Q = 1.02 and e = 1.63 in AMI/BA systems. It was found that the initial and final decomposition temperature increased with increasing the component of AMI in the copolymer.     

Hyperbranched Acrylate Copolymer via Initiator‐Fragment Incorporation Radical Copolymerization of Divinylbenzene and Ethyl Acrylate: Synthesis,Characterization, Hydrolysis,Dye‐Solubilization,Ag Particle‐Stabilization,and Porous Film Formation

Summary: Soluble hyperbranched acrylate copolymers were prepared by the copolymerization of divinylbenzene (0.10 mol · L^?1) and ethyl acrylate (0.50 mol · L^?1) using dimethyl 2,2′‐azoisobutyrate of high concentrations (0.30–0.50 mol · L^?1) as initiator at 70 and 80 °C in benzene. The copolymer formed at 80 °C for 1 h showed the weight‐average molecular weight of 2.5 × 10⁵, the small radius of gyration of 10 nm, the low second virial coefficient of 5.7 × l0^?7 mL · g^?2 as shown by the MALLS measurements at 25 °C in tetrahydrofuran, and also the very low intrinsic viscosity of 0.10 dL · g^?1 at 30 °C in benzene. The hyperbranched copolymer exhibited an upper critical solution temperature (35 °C on cooling) in an acetone‐water (60:11 v/v). The copolymer showed an ability to encapsulate and transfer Rhodamine 6G as a dye probe and could stabilize Ag nanoparticles. The porous film was prepared by simply casting an acetone solution of the hyperbranched copolymer on a cover glass. The copolymer molecules radially arranged on the surface layer of the spherical pores as observed by the polarized optical microscope. The hyperbranched acrylate copolymer was hydrolyzed by KOH to yield poly(carboxylic acid).

Optical microscope image (crossed polarizers) of a porous film from copolymer solution in acetone.     

Study of the styrene–acrylic emulsion modified by hydroxyl-phosphate ester and its stoving varnish

A styrene–acrylic copolymer emulsion containing hydroxyl-phosphate as flash-rust functional monomer and hydroxypropyl acrylate as cross-linking monomer was synthesized. The effects of the hydroxyl phosphate dosage, the hydroxypropyl acrylate dosage as well as the ratio of soft to hard monomer on the emulsion and coating film were investigated. The results showed that the emulsion of 4% hydroxyl phosphate function monomer and 3% hydroxypropyl acrylate with soft and hard monomer ratio of 1:1.6 and modified emulsion and amino resin ratio of 6:1 resulted in a coating film with the best performance.     

Synthesis,Characterization, Reactivity Ratio and Photo Crosslinking Properties of the Copolymer of 4-Cinnamoyl Phenyl Methacrylate with Butyl Methacrylate

Copolymers of 4-cinnamoyl phenyl methacrylate (4-CPMA) and n-butyl methacrylate (BMA) were prepared in a methyl ethyl ketone (MEK) solution with benzoyl peroxide (BPO) as an initiator at 70°C. They were characterized with UV, IR, ¹H-NMR, ¹³C-NMR, TGA, DSC and gel permeation chromatography. Copolymers were prepared by using different feed ratio of monomers. The monomer reactivity ratios determined by the method of Kelen-Tudos (K-T) were r₁ (CPMA) = 2.32, r₂ (BMA) = 0.56. The glass transition temperature of the copolymer shows a single Tg indicating the formation of random copolymer for all of the monomer feed composition. Thermogravimetric analysis in air has shown that the initial decomposition temperature of the copolymer was above 220°C. The photocrosslinking properties of the copolymer were examined by UV irradiation with polymer film.     

Preparation of asymmetric film by blending two kinds of polymer emulsions having greatly different storage stabilities

Two kinds of anionic polymer emulsions with different particle sizes were blended and cast on a release-paper at 30°C. One was poly(butyl acrylate) emulsion, and the other was ethyl acrylate–methyl methacrylate (1 : 1, weight ratio) copolymer emulsion. They were produced by emulsifier-free emulsion polymerization. The blend films prepared in an appropriate range of the blend ratio had a great difference in tackiness between both surfaces: The air-side surface exhibited tackiness and the release-paper side showed nontackiness. The forming mechanism is discussed.     

Structure and mechanical properties of the hybrid films of well dispersed SiO2 nanoparticle in polyimide (PI/SiO2) prepared by sol–gel process

Methyl methacrylate-butyl acrylate structural latexes were synthesized by two-stage seeded emulsion polymerization using 1,1-diphenylethylene (DPE) as a control reagent. In the first stage, the seed latex particles with the precursor poly (methyl methacrylate-DPE) (P(MMA-DPE)) were prepared, and then the second monomer n-butyl acrylate (nBA) was swollen into the seed latex particles under stirring at room temperature. In the second stage, the polymerization of nBA was thermally initiated at 80 °C, and the latex particles composed of block copolymer were synthesized. The size and morphology of the latex particles were investigated by light scattering and TEM. The contact angles of different latex films were also measured. The block copolymer was characterized by size exclusion chromatography, nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. Microphase separation of the block copolymer was examined using atomic force microscopy.     

Soap-free seeded emulsion copolymerization of MMA onto PU-A and their properties

The polyurethane acrylate (PU-A) containing double bond and COOH group was synthesized by stepwise reaction of 2,4-toluene diisocyanate (TDI), polyetherdiol (PPG), dimethylolpropionic acid (DMPA), and 2-hydroxpropyl acrylate (HPA), and the PU-A was neutralized with triethylamine (TEA) and self-emulsified in water to form the PU-A emulsion seed. Adding methyl methacrylate (MMA) into PU-A seed, the seeded emulsion copolymerization of MMA onto PU-A seed had been carried out at 80°C under the soap-free condition to obtain anionic latex of P(UA-MMA). The kinetic behavior of the seeded emulsion copolymerization, the MMA grafting ratio, and the crosslinking copolymer were investigated. IR spectra showed that it did form the P(UA-MMA) copolymer. The measurements revealed that the structure of the P(UA-MMA) copolymer, its latex properties and the cast film were significantly influenced by the amounts of HPA, DMPA, and MMA. The experimental results indicated that with DMPA increased, the particle size of P(UA-MMA) latex decreased, but the tensile strength of its cast film increased. Adding a small amount of HPA, it could improve the tensile strength of the cast film. With MMA content increased, the distribution of the particle size of P(UA-MMA) latex became narrow, whereas under certain amount of MMA, the tensile strength of the cast film was enhanced. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 941–947, 2001     

Synthesis and characterization of epoxy resin of 9,9′-bis-(3,5-dibromo-4-hydroxyphenyl) anthrone-10 and its jute composite

Epoxy resin of 9,9′-bis-(3,5-dibromo-4-hydroxyphenyl) anthrone-10 (EANBr, EEW 490) was synthesized and was characterized by IR and ¹HNMR . EANBr and EPK3251 cured resin (EANBrC) were characterized by DSC and TGA at 10°Cmin^?1 under nitrogen atmosphere. Broad DSC endothermic transitions of EANBr (265.3 °C) and EANBrC (291.4 °C) are due to some physical change and further confirmed by no weight loss in their TG thermograms. EANBr and EANBrC are thermally stable up to 340 °C and 310 °C, respectively. EANBr has followed single step degradation kinetics, while EANBrC has followed two step degradation kinetics. EANBr followed apparently zero order kinetics, while EANBrC followed apparently second order (1.80) and first order (0.89) degradation kinetics, respectively. Ea and A values of EANBrC (299.7 kJmol^?1 and 6.32?×?10²⁰ s^?1) were found higher than that of EANBr (201 kJmol^?1 and 2.45?×?1013 s^?1) due to more rigid nature of EANBrC. The ΔS^* value of the first step degradation of EANBrC (146.3 JK^?1 mol^?1) was found much more than that of EANBr (4.6 JK^?1 mol^?1). Jute – EANBr composite (J-EANBr) was prepared by compression molding technique at 120 °C for 5 h and under 20 Bar pressure. The observed tensile strength, flexural strength, electric strength and volume resistivity of J-EANBr are 24.7 MPa, 19.0 MPa, 1.8 kVmm^?1 and 3.5?×?10¹² ohm cm, respectively. Water absorption in J-EANBr was carried out at 30 ± 2 °C against distilled water, 10% NaCl, 10% HCl, 10% HNO₃, 10% H₂SO₄, 10% NaOH, and 10% KOH and also in boiling water. The equilibrium time and equilibrium water content for J-EANBr in different environments are 384–432 h; 12.7–15.2%, respectively. The observed equilibrium water content and diffusivity trends of J-EANBr are KOH>H₂SO₄>HCl>NaOH>H₂O>NaCl and H₂O>NaCl>NaOH>H₂SO₄>HCl>KOH, respectively. Good thermo-mechanical, electrical properties and excellent hydrolytic stability of J-EANBr may be useful for high temperature applications in diverse fields.     

Preparation of emulsifier-free acrylate cross-linkable copolymer emulsion and application in coatings for controlling indoor humidity

Indoor humidity has an important influence on our lives. Too high relative humidity (RH > 60 %) can cause the metal surface corrosion, electrical insulation fall, material deformation and so on. On the contrary, when the moisture content is too low (RH < 40 %), it causes skin chapping, decrease in respiratory system resistance, static electricity, etc. The humidity controlling coating is a kind of composite that controls the humidity of materials. In this study, the emulsifier-free acrylate copolymer emulsion (EF-AAC) containing ketocarbonyl and carboxyl groups was synthesized and the humidity controlling coating (EF-AAC-C) was prepared by EF-AAC, adipic dihydrazide (ADH) and porous fillers. The different proportions and the contents of KPS, NaHCO₃, and the effects of polymerization time and reaction temperature on the stability of emulsion were investigated. The different ratios of fillers/emulsion and ADH/diacetone acrylamide for water resistance of coatings were also studied. Moreover, the structure of emulsifier-free acrylate copolymer was characterized by FTIR and TGA techniques. The particle morphologies were measured by transmission electron microscopy and dynamic light scattering. It showed that the distribution of emulsion particle size was narrow and uniform. The properties of humidity controlling coatings were studied with particular attention to the effects of the humidity controlling. Meanwhile, the water absorption of humidity controlling coatings was up to 260 %. The humidity controlling coatings revealed excellent properties of humidity sensitivity and humidity retention because of the composite porous structure due to fillers with emulsifier-free acrylate copolymer. The mechanism of breathing water molecules in obtained coatings was suggested and the composite could be widely used as indoor coatings for controlling humidity.     

Effects of simultaneous chemical cross-linking and physical filling on separation performances of PU membranes

The novel modified polyurethane (PU) membranes were prepared by β-cyclodextrin (CD) cross-linking and SiO₂/carbon fiber filler, simultaneously. The structures, thermal stabilities, morphologies, and surface properties were characterized by FTIR, TGA, SEM, and contact angle. The results showed that the addition of inorganic particles increased the thermal stabilities of PU membranes. The modified PU membranes possessed more hydrophobic surfaces than pure PU. In the swelling investigation, PU and its modified membranes were swelled gradually with increasing phenol content in the mixture. The membranes modified by CD cross-linking (PUCD) demonstrated the highest swelling degree. Pervaporation (PV) performances were investigated in the separation of phenol from water. Three kinds of modified membranes obtained better permeability and selectivity than PU membranes. With the feed mixture of 0.5 wt% phenol at 60 °C, the modified PU membrane by CD cross-linking and SiO₂ filler (PUCD-S) obtained the total flux of 5.92 kg μm m^?2 h^?1 which was above doubled that of PU (2.90 kg μm m^?2 h^?1). The modified PU membrane by CD cross-linking and carbon fiber filling (PUCD-C) obtained the separation factor of 51.31 which was nearly tripled that of PU (17.72). The PUCD membranes showed both better permeability and selectivity than the pure PU membranes. The increased phenol content induced an increased separation factor of PUCD and PU, but a decreased selectivity of PUCD-S and PUCD-C. The methods of CD cross-linking and inorganic particle filling were effective to develop the overall separation performances, greatly.     

含氟丙烯酸酯共聚物的制备及性能

自制含氟丙烯酸酯单体与其他丙烯酸酯分别以溶液聚合和乳液聚合制得含氟丙烯酸酯溶液共聚物(Ⅰ)和乳液共聚物(Ⅱ),并与不含氟的丙烯酸酯共聚物(Ⅲ)性能进行了对比:Ⅰ在水中浸泡96h后涂膜完好,Ⅲ剥离;Ⅱ在水中浸泡24h后吸水率为12 01%～13 65%,Ⅲ为24 87%;Ⅰ、Ⅱ分别在丙酮和w(NaOH)=5%的水溶液中浸泡24h,涂膜基本完好,Ⅲ则剥离、破裂或溶解;w(氟单体)=5%时以KH-570改性Ⅰ并按上述方法测试性能,涂膜完好,硬度由HB提高到H;Ⅰ与水的平均接触角为62 1°～68 4°,Ⅱ为53 9°～61 0°,Ⅲ为29 1°～30 5°,KH-570改性Ⅰ后为63 4°～67 3°。上述结果表明:含氟共聚物涂膜的耐水性、耐碱性、耐溶剂性和自洁性均优于不含氟的共聚物,且含氟单体与KH-570具有良好的协同作用。     

A tough noncombustible material prepared by grafting of poly(2‐ethylhexyl acrylate) with vinyl chloride

A noncombustible tough poly(vinyl chloride) (tPVC) was prepared by suspension‐grafted copolymerization of poly(2‐ethylhexyl acrylate) (poly‐EHA; elastomer) with vinyl chloride (VC). Elastomer (poly‐EHA) was prepared by emulsion, mainly homopolymerization of 2‐ethylhexyl acrylate at a temperature of 30 ± 0.1°C in the presence of a redox system and with the advantage of dosing the monomer into two portions. Grafted‐suspension copolymerization of poly‐EHA with VC was carried out at 54 ± 0.1°C, keeping other reaction conditions only slightly modified in comparison with those for the polymerization of pure VC. An optimum content of the incorporated poly‐EHA in PVC was found to be in the range 7.5–8.5 wt %, whereas notched toughness of 85–87 kJ m^?2 was reached. Both below and above the found range of the content of poly‐EHA, the toughness decreases. A copolymer prepared by a direct‐emulsion copolymerization of 2‐EHA and VC (poly‐EHA‐co‐VC) exhibited worse mechanical properties than the copolymer prepared by two polymerization steps. On the basis of experimental results, effects of the reaction procedure on the properties of resulting material are described. In addition to good mechanical properties, tPVC also shows its noncombustibly. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2355–2362, 2002