Synthesis and characterization of functional gradient copolymers of glycidyl methacrylate and butyl acrylate

Epoxy-functional spontaneous gradient copolymers of glycidyl methacrylate (G) and n-butyl acrylate (B) were synthesized via atom transfer radical polymerization (ATRP). The copolymerization reactions were carried out in toluene solution at 70 °C, using methyl 2-bromopropionate (MBrP) as initiator and copper chloride with N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (PMDETA) as the catalyst system. The kinetic behaviour of the statistical copolymerizations was studied in a wide composition interval with molar fractions of G ranging from 0.10 to 0.75. The synthesized copolymers were characterized by size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR) spectroscopy. ¹H NMR was employed to determine the copolymer composition, demonstrating the gradient character of the copolymers along the main chain in the whole monomer conversion interval. Apart from this, the sequence distribution and stereoregularity were analyzed. These microstructural experimental data agreed well with those calculated from Mayo-Lewis terminal model (MLTM) and a Bernoullian statistic with an isotacticity parameter of σ_G = 0.28 and a coisotacticity parameter of σ = 0.30.     

环氧树脂-聚丙烯酸酯乳液型复合薄膜粘合剂

本文主要叙述了环氧-丙烯酸酯聚合乳液的合成,以及该乳液粘合剂的配制;讨论了该乳液粘合剂的粘合性能及耐水、耐溶剂性能。     

高柔韧性聚氨酯丙烯酸酯的合成及应用

选用不同结构的多元醇作骨架，合成一系列高性能的聚氨酯丙烯酸树脂，并通过对聚氨酯丙烯酸树脂性能的对比研究，发现以聚丁二烯二元醇为骨架的聚氨酯丙烯酸酯树脂具有极佳的柔韧性和优异的低温耐曲折性。     

Modification of leather properties by grafting. I. Effect of monomer chain on the physico‐mechanical properties of grafted leather

Although leather has a number of desirable properties such as thermal stability and fire retardancey, in addition to high toughness, it has a few drawbacks such as weight, high water absorption, poor soil and rot resistance, and nonuniformity. If these defects are overcome, leather's usefulness would be further enhanced and its competitive position with respect to synthetics would increase. This study reports the physical and mechanical properties of buffalo leather after chemical graft copolymerization with ethyl acrylate, butyl acrylate, and 2‐ethyl hexyl acrylate using benzoyl peroxide as an initiator. The optimum conditions for grafting (e.g., monomer and initiator concentrations, temperature and time of grafting, and solvent leather ratio) were extensively investigated. The study achieved outstanding properties for buffalo leather in reduction of water uptake after grafting, especially on using 2‐ethyl hexyl acrylate and butyl acrylate monomers. FT‐IR and solid ¹³C‐NMR for leather before and after grafting confirmed the grafting process.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1478–1483, 2003     

Soap‐free emulsion copolymerization of perfluoroalkyl acrylates in the presence of a reactive surfactant

Soap‐free emulsion copolymerization of perfluoroalkyl acrylate (FA)/methyl methacrylate (MMA)/n‐butyl acrylate (n‐BA) was carried out in the presence of sodium 2‐acrylamide‐2‐methyl propanesulfonate (AMPSNa) as a reactive surfactant and potassium persulfate (KPS) as an initiator. An analysis of the effects of concentration of AMPSNa, KPS, FA as well as polymerization temperature on the kinetic features (rate of polymerization) and colloidal characteristics (mean particle diameter, particle disperse index, particle numbers, and surface charge density) was followed. NMR, FTIR, AFM, and fluorine‐selective electrode analysis were used to characterize the composition and morphology of the FA copolymers. Both AFM analysis and contact angle measurements strongly implied that the fluorinated segments migrated to the outmost surface and created films with lower surface energy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2438–2444, 2007     

用超临界二氧化碳法制备超强吸水剂

以N，N’-亚甲基双丙烯酰胺(BIS)为交联剂，研究了疏水性单体丙烯酸十八酯(OA)与亲水性单体丙烯酸(AA)在超临界二氧化碳中的聚合反应，制备了超强吸水剂。结果表明，65℃、压力大于13MPa时，制备的产物都为白色固体粉末。用超临界二氧化碳萃取技术可以对产物进行纯化，50℃、20MPa下，产物经超临界二氧化碳萃取2次后纯度可大于95％，4次后单体残留率为0．28％。该超强吸水剂的吸水率有一定下降，然而保水率却得到提高。     

Preparation of lithium-ion polymer battery using LiNi1/3Co1/3Mn1/3O2 as a cathode material and its electrochemical properties

In this work, LiNi_1/3Mn_1/3Co_1/3O₂ powders were synthesized from co-precipitated spherical metal hydroxide. In the voltage range of 2.8–4.2, 2.8–4.4, and 2.8–4.6 V, the discharge capacities of LiNi_1/3Mn_1/3Co_1/3O₂ electrode were 163, 177, and 193 mAh⋅g⁻¹, respectively. A gel polymer electrolyte (GPE) was also prepared using polyoxyalkylene glycol acrylate (POAGA) as a macromonomer. LiNi_1/3Mn_1/3Co_1/3O₂/GPE/graphite cells were prepared and their electrochemical properties were evaluated at various current densities and temperatures. The ionic conductivity of the GPE was more than 6.2 × 10⁻³ S⋅cm⁻¹ at room temperature. POAGA-based cells were showed good electrochemical performances such as rate capability, low-temperature performance, and cycleability.