scholarly journals Flame Retardant Submicron Particles via Surfactant-Free RAFT Emulsion Polymerization of Styrene Derivatives Containing Phosphorous

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1244
Author(s):  
Taeyoon Kim ◽  
Joo-Hyun Song ◽  
Jong-Ho Back ◽  
Bongkuk Seo ◽  
Choong-Sun Lim ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Flame Retardant ◽  
Emulsion Polymerization ◽  
Degree Of Polymerization ◽  
Submicron Particles ◽  
Poly Ethylene Glycol ◽  
Raft Agent ◽  
Flame Retardant Properties ◽  
Poly Ethylene

The reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of diethyl-(4-vinylbenzyl) phosphate (DEVBP) was performed using PEG-TTC as a macro RAFT agent. PEG-TTC (MW 2000, 4000) was synthesized by the esterification of poly (ethylene glycol) methyl ether with a carboxylic-terminated RAFT agent, composed a hydrophilic poly (ethylene glycol) (PEG) block and a hydrophobic dodecyl chain. The RAFT emulsion polymerization of DEVBP was well–controlled with a narrow molecular size distribution. Dynamic light scattering and confocal laser scanning microscopy were used to examine the PEG-b-PDVBP submicron particles, and the length of the PEG chain (hydrophilic block) was found to affect the particle size distribution and molecular weight distribution. The submicron particle size increased with increasing degree of polymerization (35, 65, and 130), and precipitation was observed at a high degree of polymerization (DP) using low molecular weight PEG-TTC (DP 130, A3). The flame retardant properties of the PEG-b-PDVBP were evaluated by thermogravimetric analysis (TGA) and micro cone calorimeter (MCC). In the combustion process, the residue of PEG-b-PDEVBP were above 500 °C was observed (A1 ~ B3, 27 ~ 38%), and flame retardant effect of PEG-b-PDEVBP submicron particles/PVA composite were confirmed by increasing range of temperature and decreasing total heat release with increasing contents of PEG-b-PDEVBP. The PEG-b-PDEVBP submicron particles can provide flame retardant properties to aqueous, dispersion and emulsion formed organic/polymer products.

Polysiloxane nanoparticles prepared by emulsion polymerization under microwave irradiation

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Yang Bo ◽  
He Hui ◽  
Chen Riping ◽  
Jia Demin
Keyword(s):  
Particle Size ◽  
Microwave Irradiation ◽  
Emulsion Polymerization ◽  
Conventional Heating ◽  
Poly Ethylene Glycol ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Equilibrium Conversion ◽  
Poly Ethylene ◽  
Cationic Ring Opening Polymerization

AbstractEmulsion polymerization of octamethyl cyclotetrasiloxane (D4) under microwave irradiation (MI) was studied. The polysiloxane (PSi) nanoparticles via cationic ring-opening polymerization of D4 were obtained by using the dodecylbenzene sulphonic acid (DBSA), sodium dodecylbenzene sulphate (SDBS) and poly(ethylene glycol) monooctylphenyl ether (OP-10) as the catalyst and the emulsifiers respectively. The particle size analyzer and transmission electron microscope (TEM) were used to determine the particle size of PSi emulsions. The results show that, the particle size of PSi emulsions prepared under MI is substantially smaller and the particle distribution is narrower compared with that under conventional heating (CH). With the aid of MI, the polymerization rate and the equilibrium conversion are enhanced. The polydispersity index (PDI) and molecular weight (Mw) measured by GPC indicate that under MI, PDI of PSi is narrower and Mw of PSi at high temperature is lower than those under CH.

scholarly journals Isothermal Crystallization Kinetics of Poly(ethylene oxide)/Poly(ethylene glycol)-g-silica Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 648
Author(s):  
Xiangning Wen ◽  
Yunlan Su ◽  
Shaofan Li ◽  
Weilong Ju ◽  
Dujin Wang
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Poly Ethylene Glycol ◽  
Isothermal Crystallization Kinetics ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Kinetics Of

In this work, the crystallization kinetics of poly(ethylene oxide) (PEO) matrix included with poly(ethylene glycol) (PEG) grafted silica (PEG-g-SiO2) nanoparticles and bare SiO2 were systematically investigated by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM) method. PEG-g-SiO2 can significantly increase the crystallinity and crystallization temperature of PEO matrix under the non-isothermal crystallization process. Pronounced effects of PEG-g-SiO2 on the crystalline morphology and crystallization rate of PEO were further characterized by employing spherulitic morphological observation and isothermal crystallization kinetics analysis. In contrast to the bare SiO2, PEG-g-SiO2 can be well dispersed in PEO matrix at low P/N (P: Molecular weight of matrix chains, N: Molecular weight of grafted chains), which is a key factor to enhance the primary nucleation rate. In particular, we found that the addition of PEG-g-SiO2 slows the spherulitic growth fronts compared to the neat PEO. It is speculated that the interfacial structure of the grafted PEG plays a key role in the formation of nuclei sites, thus ultimately determines the crystallization behavior of PEO PNCs and enhances the overall crystallization rate of the PEO nanocomposites.

Controlled Release Behaviors of Ketoprofen from Matrix Polymer of Chitosan and poly(ethylene glycol)

2013 ◽  
Vol 813 ◽  
pp. 399-402
Author(s):  
Chimsook Thitipha ◽  
Thitiphan Chimsook
Keyword(s):  
Particle Size ◽  
Controlled Release ◽  
Drug Release ◽  
Ethylene Glycol ◽  
Diffusion Method ◽  
Poly Ethylene Glycol ◽  
Matrix Polymer ◽  
Percentage Yield ◽  
Poly Ethylene ◽  
Composition Ratios

The aim of present work was to prepare floating microsphere of ketoprofen using matrix polymer of chitosan and poly (ethylene glycol) by solvent diffusion method. The floating microsphere of ketoprofen was prepared from matrix polymer of chitosan and poly (ethylene glycol) with various composition ratios and evaluated such as particle size, drug compatibility and drug release of microspheres. The scanning electron microscopy of microspheres confirmed their hollow structures with smooth surface. Formulation CPK 4 to CPK 6 exhibited the best controlled release pattern in ketoprofen. The concentration and size of poly (ethylene-glycol) affected the particle size, percentage yield and drug release of microspheres.

The Use of Novel F-RAFT Agents in High Temperature and High Pressure Ethene Polymerization: Can Control be Achieved?

2007 ◽  
Vol 60 (10) ◽  
pp. 788 ◽  
Author(s):  
Markus Busch ◽  
Marion Roth ◽  
Martina H. Stenzel ◽  
Thomas P. Davis ◽  
Christopher Barner-Kowollik
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
High Temperature ◽  
Degree Of Polymerization ◽  
Molecular Weight Distributions ◽  
High Pressure High Temperature ◽  
Reversible Addition ◽  
Weight Distributions ◽  
Raft Agent ◽  
Initial Results

Simulations are employed to establish the feasibility of achieving controlled/living ethene polymerizations. Such simulations indicate that reversible addition–fragmentation chain transfer (RAFT) agents carrying a fluorine Z group may be suitable to establish control in high-pressure high-temperature ethene polymerizations. Based on these simulations, specific fluorine (F-RAFT) agents have been designed and tested. The initial results are promising and indicate that it may indeed be possible to achieve molecular weight distributions with a polydispersity being significantly lower than that observed in the conventional free radical process. In our initial trials presented here (using the F-RAFT agent isopropylfluorodithioformate), a correlation between the degree of polymerization and conversion can indeed be observed. Both the lowered polydispersity and the linear correlation between molecular weight and conversion indicate that control may in principle be possible.

Hydrolytically and Reductively Degradable High-Molecular-Weight Poly(ethylene glycol)s

2007 ◽  
Vol 208 (24) ◽  
pp. 2642-2653 ◽  
Author(s):  
Alena Braunová ◽  
Michal Pechar ◽  
Richard Laga ◽  
Karel Ulbrich
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
High Molecular Weight ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
High Molecular Weight Poly

Amphiphilic Poly(ethylene oxide) Macromolecular RAFT Agent as a Stabilizer and Control Agent in ab Initio Batch Emulsion Polymerization

2008 ◽  
Vol 41 (12) ◽  
pp. 4065-4068 ◽  
Author(s):  
Jutta Rieger ◽  
François Stoffelbach ◽  
Chuong Bui ◽  
David Alaimo ◽  
Christine Jérôme ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Ab Initio ◽  
Emulsion Polymerization ◽  
Control Agent ◽  
Raft Agent ◽  
Poly Ethylene Oxide ◽  
Macromolecular Raft Agent ◽  
Poly Ethylene ◽  
And Control

Microporous Bio-Membrane Materials Based on High Molecular Weight Polylactide and Low Molecular Weight Poly(ethylene glycol)

2012 ◽  
Vol 567 ◽  
pp. 123-126
Author(s):  
Teng Fei Shen ◽  
Man Geng Lu ◽  
Li Yan Liang
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
High Weight ◽  
Low Molecular Weight ◽  
Poly Ethylene Glycol ◽  
Degradation Rates ◽  
Degradation Behaviors ◽  
The Mean ◽  
Poly Ethylene ◽  
Lower Glass Transition Temperature

In this work, microporous membrane biomaterials based on high weight molecular polylactide (PLA) and low molecular weight poly(ethylene glycol) (PEG) using rapid solvent evaporation method were prepared and investigated. The effect of PEG segments added on the thermal and degradation behaviors was studied. According to the results, produced PLA/PEG biomaterial has lower glass transition temperature (Tg)in comparison with neat PLA. It was also found that the degradation rates of the PLA/PEG biomaterials were significantly increased with adding of PEG, which explained by increasing hydrophilic groups. For better porous fixation, CL-blocked polyisocyanate (CL-bp), which was synthesized from reaction of isophorone diisocyanate (IPDI) with dimethylol propionic acid (DMPA) and Trimethylolpropane (TMP) followed by addition of caprolactam (CL), were introduced. The microporous forms were observed by the scanning electron microscope (SEM), which showed the mean diameters of prepared PLA/PEG microporous were around 10μm.

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