ADVANCES IN POLYMER TECHNOLOGY
·
2021
·Vol. 2021
·期 1
·2966920
·
IF 2.389
Min Qiu,Liang Xiang,Minjing Shang,Yuanhai Su
Microreactors are a promising platform for continuous synthesis of polymer latices when combined with emulsion polymerization. However, this application has long been haunted by fouling and clogging problems. In this work, we proposed the strategy of conducting differential microemulsion polymerization in microreactors within a biphasic slug flow and achieved rapid and stable preparation of nanosized PMMA latices (polymeric content as high as 15.7% with average particle size smaller than 20 nm). We started by exploring the temperature thresholds with thermal and redox initiation, the effect of initiator concentration, and the kinetic characteristics of microemulsion polymerization at different temperatures. Then, as for the differential microemulsion polymerization, extensive investigation was made into the effects of the volumetric flow ratio, the prepolymerization time, the initiator concentration, and the solid content of the initial microemulsion. Finally, we compared the differential microemulsion polymerization with the soap-free emulsion polymerization in the slug flow. The striking advantages in the polymerization rate, the average particle diameter, and the size distribution reflected higher density of particle nuclei, larger specific surface area of particles, and the pivotal effect of the persistent particle nucleation in the microemulsion polymerization.
研究领域:
化学工程
·
材料科学
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DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2016
·Vol. 23
·期 6
·1-8
·
IF 1.969
Li Hui,Zhang Qiuyu
In this paper, P n BA- g -PMMA brush-like and centipede multigraft copolymers were synthesized via DPE seeded emulsion polymerization and miniemulsion polymerization. PMMA macromonomers with single tail and double tails were prepared by DPE-technique in emulsion and Steglich esterification. Then P n BA- g -PMMA multigraft copolymers were obtained by miniemulsion copolymerization. The molecular weight and polydispersity indices of PMMA macromonomers and graft copolymers were characterized by GPC. The structural characteristics, weight content of PMMA and the number of grafting sites in brush-like and centipede multigraft copolymers were determined by 1 H NMR. The thermal performance of graft copolymers were analyzed by DSC and TGA. AFM confirmed microphase separation between P n BA block and PMMA block.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 38
·期 1
·9-16
·
IF 2.804
Man Shou-Kuo,Wang Xiao,Zheng Jin-Wen,An Ze-Sheng
Polymerization-induced self-assembly (PISA) is an efficient and versatile method to afford polymeric nano-objects with polymorphic morphologies. Compared to dispersion PISA syntheses based on soluble monomers, the vast majority of emulsion PISA formulations using insoluble monomers leads to kinetically-trapped spheres. Herein, we present aqueous emulsion PISA formulations generating worms and vesicles besides spheres. Two monomers with different butyl groups, n -butyl ( n BHMA) and tert -butyl ( t BHMA) α -hydroxymethyl acrylate, and thus possessing different water solubilities were synthesized via Baylis-Hillman reaction. Photoinitiated aqueous emulsion polymerizations of n BHMA and t BHMA employing poly(ethylene glycol) macromolecular chain transfer agents (macro-CTAs, PEG 45 -CTA, and PEG 113 -CTA) at 40 °C were systematically investigated to evaluate the effect of monomer structure and solubility on the morphology of the generated block copolymer nano-objects. Higher order morphologies including worms and vesicles were readily accessed for t BHMA, which has a higher water solubility than that of n BHMA. This study proves that plasticization of the core-forming block by water plays a key role in enhancing chain mobility required for morphological transition in emulsion PISA.
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
Polymers
·
2016
·Vol. 8
·期 2
·55
·
IF 2.944
Baijun Liu,Yajun Wang,Mingyao Zhang,Huixuan Zhang
Particle coagulation is a facile approach to produce large-scale polymer latex particles. This approach has been widely used in academic and industrial research owing to its higher polymerization rate and one-step polymerization process. Our work was motivated to control the extent (or time) of particle coagulation. Depending on reaction parameters, particle coagulation is also able to produce narrowly dispersed latex particles. In this study, a series of experiments were performed to investigate the role of the initiator system in determining particle coagulation and particle size distribution. Under the optimal initiation conditions, such as cationic initiator systems or higher reaction temperature, the time of particle coagulation would be advanced to particle nucleation period, leading to the narrowly dispersed polymer latex particles. By using a combination of the Smoluchowski equation and the electrostatic stability theory, the relationship between the particle size distribution and particle coagulation was established: the earlier the particle coagulation, the narrower the particle size distribution, while the larger the extent of particle coagulation, the larger the average particle size. Combined with the results of previous studies, a systematic method controlling the particle size distribution in the presence of particle coagulation was developed.Keywords:emulsion polymerization;particle size distribution;coagulation;initiator
研究领域:
化学工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 32
·45111
·
IF 1.86
Yangcheng Lu,Xiaojing Liu,Guangsheng Luo
Compared with low molecular surfactants, poly(vinyl alcohol) (PVA) could afford latexes with particular tackiness as an important property for various applications. However, until now, except for some highly reactive monomers, most of monomers including styrene seldom use PVA as protective colloid in emulsion polymerization. In this work, we used oil-soluble initiator, 2,2′-azobisisobutyronitrile, to accelerate the copolymerization of styrene and divinyl benzene in PVA protected colloids and synthesize polystyrene (PS) latex within 50 min at 70 °C successfully. The reaction system could remain stable even at the monomer-to-water ratio as high as 1:4, and the polymerization in pseudo-micelles or latex particles was always dominant. The adjustment of the size of the PS latex in the range from 70 to 100 nm was facilely achieved by changing the polymerization temperature, the addition of PVA, or the monomer-to-water ratio. This method was also exploited to synthesize poly(styrene- co -methyl methacrylate) and poly(styrene- co -4-chlorostyrene) latexes, indicating prospects in applications with the advantages of high capacity and broad applicability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45111.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 21
·47552
·
IF 2.188
Dong Xu,Rui Yang
Microencapsulated phase-change materials (MEPCMs) with paraffin as the core and poly(methyl methacrylate) (PMMA) and PMMA copolymers as the shell were prepared by emulsion polymerization using redox initiators at low temperatures. Fourier transform infrared spectroscopy was used to characterize the chemical composition of MEPCMs. The thermal properties and thermal stabilities of MEPCMs were tested by differential scanning calorimetry and thermogravimetric analysis. The morphologies and sizes of the microcapsules were investigated by scanning electron microscopy and particle size distribution analysis. The results indicated that the yield of microcapsules is as high as 96.2%, and the encapsulation efficiency of paraffin is nearly 100% when the paraffin content in MEPCM is 70%. The MEPCMs have good stability: the leakage ratios of MEPCMs can be less than 1% after 50 heating–cooling cycles. Therefore, the microencapsulation of paraffin using redox initiators has good production and application prospects. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47552.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Fenping Wang,Jiawei Li,Lin Lu,Xiaofei Yan,Ziwen Xie,Dongming Qi
Reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization is a powerful tool for polymer encapsulation of pigment nanohybrids. Conventional RAFT emulsion polymers, however, contain sulfur residues that contribute to undesired odor and deleterious effects on final materials. Our strategy relies on an amphiphilic macromonomer poly(methacrylic acid-co-methyl methacrylate) P(MAA-co-MMA) with an ω-unsaturated end group synthesized in situ via cobalt(II)-mediated catalytic chain transfer polymerization (CCTP) at the surface of C.I. Pigment Blue 15:3 (PB) particles. Subsequently, these macromonomers are used as the living points to mediate the in situ sulfur-free RAFT (SF-RAFT) emulsion polymerization of monomers (butyl methacrylate (BMA) and butyl acrylate (BA)). It was found that a well-controlled polymerization process was achieved by semibatch SF-RAFT emulsion polymerization on the PB surface, as evidenced by the smooth increase in the molecular weight of polymer chains as the polymerization progressed and by transmission electron microscopy (TEM) results. Due to the sealing effect, these polymer/PB hybrid particles exhibited excellent colloidal stability in the aqueous phase. More importantly, film-forming hybrid particles with a soft P(BMA-co-BA) shell were successfully prepared in this work, which suggested that SF-RAFT-mediated polymerization may offer a useful alternative approach to traditional RAFT emulsion polymers for the preparation of organic/inorganic nanohybrids.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2015
·Vol. 38
·期 24
·4262-4268
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IF 2.737
Rihui Su,Guihua Ruan,Zhengyi Chen,Fuyou Du,Jianping Li
A new class of solid-phase extraction column prepared with grafted mercapto-silica polymerized high internal phase emulsion particles was used for the preconcentration of trace lead. First, mercapto-silica polymerized high internal phase emulsion particles were synthesized by using high internal phase emulsion polymerization and carefully assembled in a polyethylene syringe column. The influences of various parameters including adsorption pH value, adsorption and desorption solvents, flow rate of the adsorption and desorption procedure were optimized, respectively, and the suitable uploading sample volumes, adsorption capacity, and reusability of solid phase extraction column were also investigated. Under the optimum conditions, Pb 2+ could be preconcentrated quantitatively over a wide pH range (2.0–5.0). In the presence of foreign ions, such as Na + , K + , Ca 2+ , Zn 2+ , Mg 2+ , Cu 2+ , Fe 2+ , Cd 2+ , Cl − and NO 3 − , Pb 2+ could be recovered successfully. The prepared solid-phase extraction column performed with high stability and desirable durability, which allowed more than 100 replicate extractions without measurable changes of performance. The feasibility of the developed method was further validated by the extraction of Pb 2+ in rice samples. At three spiked levels of 40.0, 200 and 800 μg/kg, the average recoveries for Pb 2+ in rice samples ranged from 87.3 to 105.2%.
研究领域:
分析化学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
COLLOID AND POLYMER SCIENCE
·
2015
·Vol. 293
·期 6
·1767-1779
·
IF 1.865
Luo Yingwu,Wang An-Ni,Gao Xiang
Poly high internal phase emulsion (PolyHIPE) monolith has attracted many attentions for easy preparation, precise control on its porous structure, and excellent properties. In many applications, however, post-modification is needed to introduce functional groups onto their surfaces in order to achieve specific separation ability, reactivity or absorptivity, etc. In the current work, we proposed one-pot interfacial polymerization method to achieve composite PolyHIPEs with functional surface in one pot. It was realized by three strategies in preparing typical polystyrene PolyHIPEs from water-in-oil (W/O) HIPE: (1) introducing water-soluble initiator of potassium persulfate (KPS) and monomer of acryl acid (AA) into aqueous phase under conventional HIPE polymerization, (2) introducing KPS and AA into aqueous phase under high internal phase emulsions via reversible addition-fragmentation chain transfer (HIPE RAFT) living radical polymerization, and (3) employing reactive amphipathic MacroRAFT agent as surfactant. All these three strategies proved to be effective to generate a composite structure with different surface and bulk compositions. AA enrichment on the surface was verified by X-ray photoelectric energy spectrum (XPS) etching. Their effects on the morphology and mechanical properties were also studied.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Chunhua Li,Yifu Ruan,GengXin Liu
Polymeric soft-nanoparticles (SNPs) synthesized via microemulsion polymerization, are widely used in both academia and industry. However, achieving a significantly smaller diameter still presents a challenge. Despite the use of excess surfactants, surface tension constraints prevent microemulsion droplets from decreasing in diameter below 20 nm. Still using conventional surfactants, we introduce a simple and efficient method for mass production of SNPs down to 10–15 nm in diameter. The microemulsion is prepared by incorporating solvents that are good for both monomers and polymers. This method effectively yields significantly smaller SNPs. In the melts of such small SNPs, the Rouse-like viscous-dominant behavior is observed and fully mapped with respect to the diameter and degree of cross-linking. This was previously not observed in microemulsion polymerized SNPs. We assess the cold flow conditions by determining the ability to form transparent sheets from the powder at room temperature when subjected to pressure. It is governed by the diameter and degree of crosslinking. The ultrasmall SNPs thus have the potential to be used as fillers in various industries.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2024
·Vol. 15
·期 29
·2992-3002
·
IF 4.1
Wen Li,Guoyu Chen,Youfang Zhang,Jianyun Ding,Jie Liu,Runguo Wang,Dean Shi,Weiwei Lei,Liqun Zhang
In recent years, myrcene has emerged as a biobased alternative to isoprene for the manufacture of thermoplastic elastomers due to its similarity to isoprene, a building block for natural rubber. Through the use of highly reactive tert-butyl acrylate as a hard segment monomer, a structurally well-defined poly(tert-butyl acrylate)-b-poly(β-myrcene)-b-poly(tert-butyl acrylate) (BMB) thermoplastic triblock copolymer elastomer was synthesized by a mild reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization method utilizing a precisely devised amphiphilic macro-RAFT agent. The block copolymer BMB was confirmed by NMR, FTIR, and GPC analyses. BMB thus exhibits typical thermoplastic elastomeric properties, as indicated by its mechanical properties with an ultimate tensile strength of 3.0 MPa and an elongation at break of 195% with tert-butyl acrylate added at 50% mass ratio. The properties of BMB can be easily tuned by adjusting the hydrolysis degree, facilitating cooperative interactions in the hard phase and enhancing tensile properties. This carboxyl interaction is an effective strategy for controlling medium strength thermoplastic elastomers.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2016
·
IF 3.85
Bo Xiang,Jun Zhang
In this study, TiO 2 /acrylonitrile-styrene-acrylate (ASA) nanocomposites with different loading content of TiO 2 were prepared via in situ emulsion polymerization . Before the polymerization, TiO 2 nanoparticles were dispersed in the reaction monomer by ultrasonic to reduce the agglomeration of TiO 2 . A series of characterization were taken to study the properties of the nanocomposites. The result of Wide angle X-ray diffraction (WAXD) analysis indicated that the crystal form of TiO 2 remained unchanged after the in situ emulsion polymerization . Interestingly, the introduction of TiO 2 induced a significant improvement in the impact toughness of TiO 2 /ASA nanocomposites, which increased dramatically by about 10 kJ/m 2 compared with neat ASA. And we attributed this improvement to the better dispersibility of TiO 2 in ASA matrix which is proved by Transmission Electron Microscopy (TEM) analysis. In addition, the solar reflectance of the nanocomposites was related to the addition of TiO 2 nanoparticles. The more the TiO 2 nanoparticle was added, the higher the solar reflectance of the nanocomposite was. Moreover, the outdoor temperature test just proved the result of the solar reflectance.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）