@article { ISI:000289575500018,
	title = {Effect of composition on chain dimensions of styrene-methylmethacrylate random copolymers under theta condition},
	journal = {Journal of Macromolecular Science Part B-Physics},
	volume = {50},
	number = {5},
	year = {2011},
	month = {APR},
	pages = {996-1005},
	publisher = {TAYLOR \& FRANCIS INC},
	address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA},
	abstract = {<p>Rotational-isomeric-state (RIS)-Metropolis Monte Carlo simulations are performed on poly(styrene-ran-methylmethacrylate) random copolymers to study the intrinsic unperturbed (theta-condition) dimensions. Mean-squared end-to-end distance (\&lt; r(2)\&gt;(o)), mean-squared radius of gyration (\&lt; s(2)\&gt;(o)), and characteristic ratio (C(n)) have been calculated for these copolymers constituted by different overall chemical compositions (styrene fractions 0.29, 0.56, and 0.70). Calculations were carried out with chains of 500 repeating units. With an increase in the styrene content there is an increase in (\&lt; r(2)\&gt;(o)), {\textquoteleft}, and C(n), in agreement with experimental observations. An increase in the fraction of trans conformational states in the backbone torsion angles is found to be responsible for the exhibited chain expansion behavior. The dimensions calculated by the Monte Carlo simulations agree well with experimental values reported in the literature.</p>},
	keywords = {chain dimensions, Monte Carlo, poly(methyl methacrylate), Polystyrene, random copolymer, theta conditions},
	issn = {0022-2348},
	doi = {10.1080/00222348.2010.497414},
	author = {Karyappa, Rahul B. and Natarajan, Upendra}
}
@article {46859,
	title = {Critical organic modifier aliphatic tail length for the formation of poly(methyl methacrylate)-montmorillonite nanocomposites},
	journal = {Polymer Engineering and Science},
	volume = {60},
	year = {2020},
	month = {JUL},
	pages = {1604-1617},
	type = {Article},
	abstract = {<p>In this article, we report the influence of organic modifier structure (alkyl chain length C8-C20, single vs ditallow) and thereby, the effect of hydrophobicity on the structure, thermal and mechanical properties of poly(methyl methacrylate) (PMMA)-clay hybrids. Melt processed PMMA-clay hybrids were characterized using wide-angle X-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The organoclays having an alkyl chain length of more than 12 CH2 groups resulted in the formation of nanocomposites. The glass transition temperature (T-g) of PMMA increased in the presence of clay. The mean-field lattice model was used to predict the free energy for nanocomposite formation, which showed a reasonable match with the experimental results and provided a general guideline for the proper selection of polymer and organoclay (ie, organic modifier) to obtain nanocomposite. Tensile modulus showed maximum improvement of 58\% for the nanocomposites compared to 9\% improvement for the composites. Tensile modulus increased with increases in the alkyl chain length of the organic modifier and clay loading. The level of improvement for the tensile properties of nanocomposites prepared from primary and secondary ammonium-modified clay is the same as that obtained with the commercial organoclays.</p>
},
	keywords = {hybrid, mechanical properties, Montmorillonite, Nanocomposites, organoclay, poly(methyl methacrylate)},
	issn = {0032-3888},
	doi = {10.1002/pen.25405, Early Access Date = MAY 2020},
	author = {Tiwari, Rajkiran R. and Natarajan, Upendra}
}
