Styrene-n-butyl acrylate

Reproduced with permission from M.R. Rao, TV. Sebastian, T.S. Radhakrishnan and P.V. Ravindran, 7o rn l/ of Applied Polymer  

Pyrolysis followed by gas chromatographic separation uses thermal energy to break down a polymeric structure to monomers and oligomers, and separation of those units for quantification. Because of the temperature limitations of the common silicone capillary column, only the dimer and trimers of the system studied can be reliably separated and detected. The major mechanism of producing dimers and trimers with pyrolysis can be attributed to thermal degradation. A relatively small amount of dimers and trimers is formed as a result of a recombination of monomers. This mechanism is demonstrated as follows. 

The intensity of the various dimer and trimer peaks in a pyrolysis gas chromatogram reflect the monomer sequence. 

Pyrolysis of an emulsion polymer is done on the dried film. The liquid emulsion is heated in the pyrolysis chamber at 250 °C for 10 minutes and allowed to coalesce to a solid. A volatility experiment showed there were no detectable materials released during this period. 

The response of the FID detector is assumed equal for all three styrene-centred trimers and for all three n-butyl acrylate-centred trimers in this study. Essentially, FID is a carbon atom counter any components having the same number of carbon atoms should have the same response. The styrene-centred trimers have 22-24 carbon atoms the difference in carbon atoms is less than 5 % around those trimers. This fact makes the equal response assumption valid. The same argument also applied to w-bntyl acrylate-centred trimers. 

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Al-Ghamdi GH, Sudol ED, Dimonie VL, et al. (2006) Encapsulation of titanium dioxide in styrene/n-butyl acrylate copolymer by miniemulsion polymerization. J Appl Polym Sd 101 3479-3486... 

Percy and coworkers [39,40] synthesized colloidal dispersions of polymer-silica nanocomposite particles by homopolymerizing 4-vinylpyridine or copolymerizing 4-vinylpyridine with either methyl methacrylate, styrene, n-butyl acrylate or n-butyl methacrylate in the presence of fine-particle silica sols using a free-radical in aqueous media at 60°C. No surfactants were used and a strong acid-based interaction was assumed to be a prerequisite for nanocomposite formation. The nanocomposite particles had comparatively narrow size distributions with mean particle diameters of 150-250 nm and silica contents between 8 and 54 wt.%. The colloidal dispersions were stable at solids contents above 20 wt.%. 

Recently, a series of styrene-n-butyl acrylate copolymer latexes were prepared by conventional or miniemulsion polymerization techniques which incorporated TMI and/or methacrylic acid (MAA), and the interfacial crosslinking behaviour of films derived firom these latexes was investigated [33]. It was shown that crosslinking was dramatically enhanced in the presence of MAA. However, films prepared with TMI also crosslinked in the presence of atmospheric moisture with time at room temperature. This work also demonstrated the stability of... 

Many investigators have studied polymer surfaces for years [74,75] and have been successful in determining combinations of two or more valence states [76,77] by the mathematical process of deconvoluting the peak assignments [78]. It was only recently that latexes were examined by ESCA. Davies et al. [79] prepared a series of homopolymers of poly(methyl methacrylate) (PMMA) and poly(butyl methacrylate) (PBMA), and also poly[(methyl methacrylate)-co-(butyl methacrylate)] (PMMA-PBMA), by surfactant-free emulsion polymerization. It was found that the surface of the latex film was rich in PMMA, which may possibly be explained by the reactivity ratios for the MMA/BMA system (ri = 0.52 and rj = 2.11) [80], Recently, Arora et al. carried out angle-dependent ESCA studies on a series of films prepared from core-shell ionomeric latexes (with a polystyrene core and a styrene/n-butyl acrylate/ methacrylic acid copolymer shell) to determine the distribution of carboxyl groups in the films [81,82]. 

Styrene/n-butyl acrylate latexes Polarized ATR Orientation of adsorbed sodium dioctylsulfosuccinate (SDOSS) surfactant 1127... 

The diffusion and reaction of amino-telechelic polybutadiene in poly(styrene-n-butyl acrylate/ TMI)(PSBT) was studied. Amonodisperse seed latex was prepared by semicontinuous emulsion polymerisation. Two core-shell latices were also prepared semicontinuously, using the seed latex as the core and poly(styrene-n-butyl acrylate) as the shell. These monodisperse latices were mixed with equivalent amounts of the amino-telechelic polybutadiene artificial latex before casting into films. Consumption of the TMI (dimethyl meta-isopropenyl benzyl isocyanate) in these films was monitored by FTIR as a function of time and the amino/TMI ratio. 6 refs. 

Structure Determination of Styrene-n-Butyl Acrylate Copolymers... 

No harmful effects on health have been observed that could have been caused by processing Terblend S under normal conditions of industrial practice in well-ventilated workplace. Under such conditions concentrations of styrene, n-butyl acrylate, and aciylonitrile are well below permitted concentrations. 

Figure 5.14 GC pyrogram at 500 °C of a 50 50% styrene-n-butyl acrylate homogenous emulsion polymer.

The degree of structure, i.e., number average sequence lengths, also composition were determined for styrene-n-butyl acrylate copolymers and compared to those obtained for homogenous, i.e., non-structured (random), copolymers. 

Cheng-Yu Wang et af applied pyrolysis gas chromatography to the determination of the structure of styrene-n-butyl acrylate copolymers. The number average sequence length which reflects monomer arrangement was calculated using formulae that incorporate pure trimer peak intensities and hybrid trimer peak intensities. 

Figure 3.8. Number of particle nuclei per unit volume of water versus time profiles for surfactant-free emulsion polymerization of different monomers obtained from the model developed by Song and Poehlein [47, 48], The symbols St, BA, MMA, VCI, and VA denote styrene, n-butyl acrylate, methyl methacrylate, vinyl chloride, and vinyl acetate, respectively.

Representative computer simulation results for surfactant-free emulsion polymerizations of different monomers obtained from the model of Song and Poehlein [47, 48] are illustrated in Figure 3.8. The rate of particle nucleation during the early stage of polymerization in increasing order is styrene < n-butyl acrylate < methyl methacrylate < vinyl chloride < vinyl acetate. This trend... 

These equations are consistent with the work of Nomura and Fujita [82]. The validity of Eqs. (4.36)- (4.38) was confirmed experimentally for the emulsion copolymerizations of the styrene-methyl acrylate, styrene-n-butyl acrylate and methyl acrylate-n-butyl acrylate pairs. As a result of this... 

Figure 5.1. Rate of Ostwald ripening for emulsions as a funotion of the solubility of the constituent in water. The constituents of the oil phase include />alkanes (n = 9-16) [19] and some common monomers. St, BA, and MMA represent styrene, n-butyl acrylate, and methyl methacrylate, respectively. The data of the solubility of monomers in water were used to estimate the Ostwald ripening rate of the homogenized monomer droplets via the extrapolation method.

GugUotta et al. [23] developed a new approach to estimate the monomer conversion and copolymer composition in semibatch emulsion copolymerization systems based on reaction calorimetric measurements. The vaUdity of this technique was confirmed by the semibatch emulsion copolymerizations of both the styrene-n-butyl acrylate and vinyl acetate-n-butyl acrylate. 

ITP from a multifunctional macrotransfer agent was also used to prepare poly(e-caprolactone) (PCL)-based graft copolymers. Thus, FTP of styrene, n-butyl acrylate, and N,N-dimethylacrylamide was performed in the presence of poly(e-caprolaaone-co-a-iodo-e-caprolactone) to obtain PCL- -PS, PCL- -PnBuA and PCL-g-PDMA, respectively. ... 

Figure 4.4 Experimentally determined monomer fractions in latex particles as a function of the monomer fraction in the monomer droplets. Q methyl acrylate-vinyl acetate in a poly-(MA-VAc) copolymer latex. A methyl acrylate- styrene, n-butyl acrylate-styrene, methyl acrylate-n-butyl acrylate, methyl acrylate-methyl methacrylate and methyl methacrylate-styrene on several (co)polymer seeds. The solid line represents the prediction by Equation 4.13 (Verdurmen-Noel, 1994).

Reliable rate constants kp are available for styrene, " n-butyl acrylate, methyl and other alkyl methacrylates. Data for other monomers can be found in Polymer Handbook or in the recent review by Beuermann and Buback. ... 

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