Abstract
The monomer of poly(lactide), i.e. lactic acid is an optically active compound and thus renders optical activity in the polymer itself. In the present studies highly crystalline and low crystalline grades of poly(lactide) were used to prepare blends with different d- and l-ratios to explore the relation between d- and l-content and various properties of poly(lactide). Optical rotation was measured by Polarimetry to analyse d-content in the blends which was found to vary from 0.05 to 4.14 %. Polarized light microscopy revealed that both the growth rate and final average size of the spherulites increased with the decrease of d-content. The crystallinity was measured by differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD) methods. It was noticed that a small change in d-content produced remarkable changes in crystallinity and other properties of the blends. The mechanical properties were slightly modified with the decrease in d-content.
Similar content being viewed by others
References
Xia XL, Liu WT, ang XYT, Shi XY, Wang LN, He SQ, Zhu CS (2014) Degradation behaviors, thermostability and mechanical properties of poly (ethylene terephthalate)/polylactic acid blends. J Cent South Univ 21(5):1725–1732. doi:10.1007/s11771-014-2116-z
Aslan S, Calandrelli L, Laurienzo P, Malinconico M, Migliaresi C (2000) Poly (d, l-lactic acid)/poly (∈-caprolactone) blend membranes: preparation and morphological characterisation. J Mater Sci 35(7):1615–1622
Ovitt TM, Coates GW (1999) Stereoselective ring-opening polymerization of meso-lactide: synthesis of syndiotactic poly (lactic acid). J Am Chem Soc 121(16):4072–4073
Auras RA, Lim LT, Selke SE, Tsuji H (2011) Poly (lactic acid): synthesis, structures, properties, processing, and applications, vol 10. Wiley, New Jersey
Jiang X, Luo Y, Tian X, Huang D, Reddy N, Yang Y (2010) Chemical Structure of Poly(Lactic Acid). Poly(Lactic Acid). Wiley, New Jersey, pp 67–82. doi:10.1002/9780470649848.ch6
Lim L, Auras R, Rubino M (2008) Processing technologies for poly (lactic acid). Prog Polym Sci 33:820–852. doi:10.1016/j.progpolymsci.2008.05.004
Urayama H, Moon SI, Kimura Y (2003) Microstructure and thermal properties of polylactides with different L -and D -unit sequences : importance of the helical nature of the L -sequenced segments. Macromol Mater Eng 288:137–143. doi:10.1002/mame.200390006
Saeidlou S, Huneault MA, Li H, Park CB (2012) Poly(lactic acid) crystallization. Prog Polym Sci 37(12):1657–1677. doi:10.1016/j.progpolymsci.2012.07.005
Auras R, Harte B, Selke S (2004) An Overview of polylactides as packaging materials. Macromol Biosci 55(4):835–864. doi:10.1002/mabi.200400043
Feng LD, Sun B, Bian XC, Chen ZM, Chen XS (2010) Determination of d-lactate content in poly(lactic acid) using polarimetry. Polym Test 29:771–776
Fambri L, Migliaresi C (2010) Crystallization and thermal properties. Poly(lactic acid). Wiley, New Jersey, pp 113–124. doi:10.1002/9780470649848.ch9
Chen CC, Chueh JY, Tseng H, Huang HM, Lee SY (2003) Preparation and characterization of biodegradable PLA polymeric blends. Biomaterials 24:1167–1173
Pavia FC, La Carrubba V, Brucato V (2009) Tuning of biodegradation rate of PLLA scaffolds via blending with PLA. IntJ Mater Form 2(1):713–716
Drapier-Beche N, Fanni J, Parmentier M (1999) Physical and chemical properties of molecular compounds of lactose. J Dairy Sci 82(12):2558–2563. doi:10.3168/jds.S0022-0302(99)75510-4
Yoo ES, Im SS (1999) Effect of crystalline and amorphous structures on biodegradability of poly(tetramethylene succinate). J Polym Environ 7(1):19–26. doi:10.1023/a:1021838017958
Fischer EW, Sterzel HJ, Wegner G (1973) Investigation of the structure of solution grown crystals of lactide copolymers by means of chemical reactions. Colloid Polym Sci 251(11):980–990. doi:10.1007/bf01498927
Yasuniwa M, Tsubakihara S, Ohoshita K, Tokudome SI (2001) X-ray studies on the double melting behavior of poly(butylene terephthalate). J Polym Sci Part B Polym Phys 39(17):2005–2015. doi:10.1002/polb.1176
Yasuniwa M, Sakamo K, Ono Y, Kawahara W (2008) Melting behavior of poly(l-lactic acid): X-ray and DSC analyses of the melting process. Polymer 49(7):1943–1951. doi:10.1016/j.polymer.2008.02.034
Acknowledgments
The authors are highly grateful to the University Grant Commission, New Delhi, India for providing teacher fellowship to one of the authors (Mr. Sanjeev Kumar) and Indian Institute of Technology Delhi, India for providing all necessary facilities for carrying out the research work.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kumar, S., Bhatnagar, N. & Ghosh, A.K. Effect of enantiomeric monomeric unit ratio on thermal and mechanical properties of poly(lactide). Polym. Bull. 73, 2087–2104 (2016). https://doi.org/10.1007/s00289-015-1595-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00289-015-1595-x