Dispersion copolymerization of methyl methacrylate and acrylic acid in polar media: effects of reaction parameters on the particle size and size distribution of the copolymer microspheres

2003 ◽  
Vol 52 (5) ◽  
pp. 819-826 ◽  
Author(s):  
Jin-Xia Huang ◽  
Xiao-Ya Yuan ◽  
Xiang-Lin Yu ◽  
Hong-Tao Zhang
2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Junyi Liu ◽  
Zhengsong Qiu ◽  
Wei’an Huang ◽  
Dingding Song ◽  
Dan Bao

The poly(styrene-methyl methacrylate) latex particles as potential physical shale stabilizer were successfully synthesized with potassium persulfate as an initiator in isopropanol-water medium. The synthesized latex particles were characterized by Fourier transform infrared spectroscopy (FT-IR), particle size distribution measurement (PSD), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). FT-IR and TGA analysis confirmed that the latex particles were prepared by polymerization of styrene and methyl methacrylate and maintained good thermal stability. TEM and PSD analysis indicated that the spherical latex particles possessed unimodal distribution from 80 nm to 345 nm with the D90 value of 276 nm. The factors influencing particle size distribution (PSD) of latex particles were also discussed in detail. The interaction between latex particles and natural shale cores was investigated quantitatively via pore pressure transmission tests. The results indicated that the latex particles as potential physical shale stabilizer could be deformable to bridge and seal the nanopores and microfractures of shale to reduce the shale permeability and prevent pore pressure transmission. What is more, the latex particles as potential physical shale stabilizer work synergistically with chemical shale stabilizer to impart superior shale stability.


2006 ◽  
Vol 59 (8) ◽  
pp. 544 ◽  
Author(s):  
Catherine Lefay ◽  
Maud Save ◽  
Bernadette Charleux ◽  
Stéphanie Magnet

The nitroxide-mediated controlled free-radical copolymerization of styrene (St) and acrylic acid (AA) was used to synthesize a well-defined poly(St30%-co-AA70%) amphiphilic gradient copolymer. The latter proved to be an efficient stabilizer in the 45 wt.-% solids content, batch miniemulsion polymerizations of St and of mixtures of methyl methacrylate/n-butyl acrylate (35/65 w/w). With 2,2´-azobisisobutyronitrile as an oil-soluble initiator, polystyrene latexes with a very narrow particle distribution were obtained, whereas the water-soluble initiator, potassium persulfate, led to broad, multimodal particle size distributions. Such results were explained by the contribution of two nucleation mechanisms: droplet nucleation and homogeneous nucleation. In contrast, the poly(methyl methacrylate-co-n-butyl acrylate) latexes exhibited larger particle size and narrower particle size distributions with persulfate initiator, than the polystyrene latexes.


Polimery ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 112-118
Author(s):  
Lining Song ◽  
Zhenxu Li ◽  
Lina Yang ◽  
Ning Wang ◽  
Jie Zhao ◽  
...  

The attapulgite core-shell microcapsule type flame retardant was prepared by in situ polymerization. Attapulgite (ATP) was used as a core material with poly(methyl methacrylate) (PMMA) and poly(methyl methacrylate-co-acrylic acid) [P(MMA-co-AA)] as shell materials. The attapulgite was modified by the silane coupling agent. The effects of different shell materials and modification methods on the structure and properties of attapulgite core-shell microcapsules were studied by scanning electron microscopy, particle size distribution, infrared analysis and thermogravimetric analysis. The results showed that the coating effect was best when the amount of silane coupling agent was 1% of the attapulgite mass. The particle size of the microcapsule prepared with PMMA as shell material was uniform and the coating efficiency was better. After the copolymerization of acrylic acid (AA) in MMA shell materials, the cladding efficiency was improved. At the same time, the thermal decomposition temperature of the microcapsule shell material was greatly reduced, which is beneficial to the performance of attapulgite flame retardant.


2006 ◽  
Vol 38 (8) ◽  
pp. 835-843 ◽  
Author(s):  
Jun Takahashi ◽  
Hideki Watanabe ◽  
Jun Nakamoto ◽  
Kazuo Arakawa ◽  
Mitsugu Todo

Sign in / Sign up

Export Citation Format

Share Document