@Article{JRM.2015.634114,
AUTHOR = {M. Purushothaman, P. Santhana Gopala Krishnan, S. K. Nayak},
TITLE = {Tunable Hydrophilicity of Poly(ethyl lactate acrylate-coacrylic acid)},
JOURNAL = {Journal of Renewable Materials},
VOLUME = {3},
YEAR = {2015},
NUMBER = {4},
PAGES = {292--301},
URL = {http://www.techscience.com/jrm/v3n4/49560},
ISSN = {2164-6341},
ABSTRACT = {Four copolymers of poly(ethyl lactate acrylate-co-acrylic acid) were prepared by the solution polymerization 
technique by varying the comonomer content from 0.2 to 0.8 mole percent. The copolymers were characterized 
by FT-IR, <sup>1</sup>H-NMR and proton decoupled <sup>13</sup>C-NMR spectroscopic techniques. The reactivity ratio of ethyl 
lactate acrylate (ELA) and acrylic acid (AA) was calculated using the Fineman-Ross method and the values 
were found to be 0.101 and 0.186, respectively, indicating the formation of an alternating copolymer. From the 
wide-angle X-ray diffraction studies (WAXD), the average molecular interchain spacing (<R>) was calculated 
from the 2θ value of amorphous halo at about 20°. The <R> values varied from 5.20 to 5.64 Å and increased 
with an increase in the ELA content. The water absorption of copolymers followed Fickian absorption. 
Depending upon the copolymer composition, relative humidity and time, the water absorption of copolymers 
can be tuned to a wide range from 3 to 35% (w/w). The T<sub>g</sub>
 of copolymers decreased from 106 to −27.4°C with 
an increase in the ELA content. The copolymers were thermally stable up to 150°C and thereafter exhibited 
three-step thermal degradation in nitrogen atmosphere. The thermal stability of polymers can be explained on 
the basis of <R> value.},
DOI = {10.7569/JRM.2015.634114}
}