CO2 Capture by Liquid Solvents and their Regeneration by Thermal Decomposition of the Solid Carbonated Derivatives

The chemical capture of CO₂ by either aqueous Na₂CO₃ and K₂CO₃ or nonaqueous solutions of the amines 2‐amino‐2‐methyl‐1‐propanol (AMP) or piperazine (PZ) is described. The captured CO₂ is stored as solid NaHCO₃, KHCO₃, and AMP or PZ carbamates. Solid NaHCO₃ and KHCO₃ are decomposed at 200 °C and 250 °C, respectively, to regenerate the carbonates for their reuse. In the experiments with AMP or PZ, the solid carbamates are decomposed at 80 °C–110 °C to regenerate the free amines. The absence of water in the desorption‐regeneration step is intriguing and could have the potential of reducing one of the major disadvantages of aqueous absorbents, namely the energy cost of the regeneration step and amine degradation, yet preserving the efficiency of the absorption in the liquid phase.     

Multi-methacrylated star-shaped,photocurable poly(methyl methacrylate) macromonomers via quasiliving ATRP with suppressed curing shrinkage

Novel, star-shaped multifunctional poly(methyl methacrylate) (PMMA) macromonomers with well-defined average number of pendant methacrylate groups were synthesized by copolymerizing MMA with 2-hydroxyethyl methacrylate (HEMA) via quasiliving ATRP with a tetrafunctional initiator in methanol at 10 °C, followed by methacrylation of the hydroxyl groups of the HEMA units. The resulting tailor-made poly(methyl methacrylate-co-2-methacryloylethyl methacrylate), P(MMA-co-MEMA), multifunctional macromonomers were used as cross-linking agents in photocuring of MMA, a solvent for its own polymer, and thus chemically homogeneous PMMA networks were formed in which the tetrafunctional initiator moiety provides inherent, additional branching points in the resulting cross-linked materials. This approach, even in the presence of relatively low amounts of macromonomers of ∼35–45%, provides sol-free products and up to ∼40% less polymerization shrinkage than that by curing of MMA with a conventional low molecular weight bifunctional methacrylate. These new, unique star-shaped PMMA macromonomers are potential cross-linkers in a variety of solvent-free applications where low curing shrinkage and high conversions are critical requirements, such as in several engineering materials, coatings, dental fillings and restorations, bone cements etc.     

Synthesis of triphenyl phosphine oxide‐containing polymers via atom transfer radical polymerization

Bis[(4 ‐β‐(2‐bromopropanoate)ethoxy)phenyl]phenylphosphine oxide was used for the first time as the initiator of atom transfer radical polymerization of styrene and methyl methacrylate in the presence of CuBr/N, N,N′, N″, N″‐pentamethyldiethylenetriamine as catalyst/ligand and dimethyl sulfoxide as solvent. The presence of phosphine oxide linkages in the backbone gives the polymers special properties; low T_g, high char yield, and decreases the oxygen induction time value. A linear increase of number average molecular weight (M_n) versus monomer conversion was observed, and the molecular weight distribution was relatively narrow (M_w/M_n = 1.1–1.3). FTIR, ¹HNMR, gel permeation chromatography, ultraviolet spectroscopies were used for the characterization of the related polymers. The thermal properties of these polymers were investigated by differential scanning calorimetry and thermogravimetric analysis. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation of poly(styrene‐co‐isobornyl methacrylate) beads having controlled glass transition temperature by suspension polymerization

The styrene (St) and isobornyl methacrylate (IBMA) random copolymer beads with controlled glass transition temperature (T_g), in the range of 105–158°C, were successfully prepared by suspension polymerization. The influence of the ratios of IBMA in monomer feeds on the copolymerization yields, the molecular weights and molecular weight distributions of the produced copolymers, the copolymer compositions and the T_gs of these copolymers was investigated systematically. The monomer reactivity ratios were r₁ (St) = 0.57 and r₂ (IBMA) = 0.20 with benzyl peroxide as initiator at 90°C, respectively. As the mass fraction of IBMA in monomer feeds was about 40 wt %, it was observed that the monomer conversion could be up to 90 wt %. The fractions of IBMA unit in copolymers were in the range of 35–40 wt % and T_gs of the corresponding copolymers were in the range of 119.6–128°C while the monomer conversion increased from 0 to greater than 90 wt %. In addition, the effects of other factors, such as the dispersants, polymerization time and the initiator concentration on the copolymerization were also discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Nitroanilines enhancing the holographic data storage characteristics of the 9,10‐phenanthrenequinone‐doped poly(methyl methacrylate) photopolymer

This article describes an approach toward improving the characteristics of a photopolymer for holographic data storage application. The maximum diffraction efficiency (η_max) and dynamic range (M#) of 9,10‐phenanthrenequinone (PQ)‐doped poly(methyl methacrylate; PMMA) both improved significantly after co‐doping with one of three nitroanilines—N,N‐dimethyl‐4‐nitroaniline (DMNA), N‐methyl‐4‐nitroaniline (MNA), and 4‐nitroaniline (pNA). In particular, the value of η_max increased from 38% for the PMMA/PQ system to 72% for the PMMA/PQ/DMNA system (a 1.89‐fold improvement) and the value of M# increased accordingly from 2.7 to 7.3 (a 2.70‐fold improvement). Thus, the holographic data storage characteristics of PMMA/PQ photopolymers can be improved through co‐doping with nitroaniline compounds. We also investigated the mechanism of the nitroaniline‐induced improvement in optical storage performance using proton nuclear magnetic resonance and X‐ray photoelectron spectroscopy. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Investigation on the reaction between polyhexamethylene guanidine hydrochloride oligomer and glycidyl methacrylate

Polyhexamethylene guanidine hydrochloride (PHMG) oligomer is attracting increasing attention for its highly efficient biocidal activity and nontoxicity. To make it bearing carbon‐to‐carbon double bonds and enlarge its application in production of antimicrobial materials via copolymerization, PHMG oligomer was modified via reaction with glycidyl methacrylate (GMA). The influence of reaction parameters on the conversion rate of GMA was investigated using ultraviolet absorption spectroscopy. The structures of PHMG oligomer before and after modification were characterized by Fourier transform infrared spectrometry, Raman spectrometry, nuclear magnetic resonance spectrometry, and electrospray ionization time‐of‐flight mass spectrometry. The results show that carbon‐to‐carbon double bond is successfully introduced into the modified PHMG oligomer. At a feeding molar ratio of GMA to PHMG of 1.0, the conversion rate of GMA reached up to 75% after 60 h of reaction at 60°C in dimethyl sulfoxide. Also, there is an activity difference in the different aminos of PHMG oligomer: the primary amino is ready to react with epoxy of GMA, while the guanidyl amino hardly reacts with GMA due to the p‐π conjugation. Furthermore, the modified PHMG oligomer was used as comonomer to synthesize acrylonitrile copolymer, showing excellent antimicrobial activity against Staphylococcus aureus. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Solvent Extraction of Indium,Gallium, and Zinc Ions with Acidic Organophosphates having Bulky Alkyl Groups

The extraction equilibria of In³⁺, Ga³, and Zn²⁺ with bis(4‐ethylcyclohexyl)phosphoric acid (D4ECHPA), bis(4‐cyclohexylcyclohexyl)phosphoric acid (D4DCHPA), and bis(2‐ethylhexyl)phosphoric acid (D2EHPA) were investigated in acidic aqueous sulfate media. The order of extractability of metal ions is D4DCHPA > D2EHPA > D4ECHPA, which corresponds to the lipophilicity (log P) of the extractants. The separation factors, β_(In/Ga) and β_(Ga/Zn), of D4ECHPA and D4DCHPA are greater or comparable than that of D2EHPA, because of the steric hindrance of the bulky cyclohexyl groups. In³⁺ can be therefore separated from simulated liquor containing a high concentration of Zn²⁺ by D4DCHPA.     

PP固相接枝GMA微观聚合动力学研究

基于聚丙烯(PP)固相接枝聚合的终止反应主要是自由基单基终止反应的假设提出相应的接枝聚合机理,并建立聚合速率模型。实验考察了PP接枝甲基丙烯酸缩水甘油酯(GMA)体系单体浓度、引发剂浓度、聚合温度与聚合初期接枝速率的依赖关系。结果表明:初始聚合速率与单体浓度呈1.57次方、与引发剂浓度呈0.48次方关系,与聚合温度关系服从Arrhenius方程,并求得接枝反应的表观活化能Ea为86.63kJ/mol。     

三氟甲基磺酸铜催化果糖醇解制备乙酰丙酸甲酯

采用三氟甲基磺酸铜为催化剂催化果糖醇解制备乙酰丙酸甲酯,考察催化剂种类、催化剂用量、反应温度、反应压力和反应时间等对乙酰丙酸甲酯收率的影响。结果表明,在反应压力为2 MPa、果糖0.75 g、甲醇24 g、催化剂用量0.36 g和反应温度120 ℃条件下反应2.0 h,果糖完全被转化,乙酰丙酸甲酯收率达88.1%。