Toughening modification of polyester–urethane networks incorporating oligolactide and oligocaprolactone segments by utilizing castor oil as a core molecule

  • Shohei Matsuda
  • Ayaka Shibita
  • Toshiaki Shimasaki
  • Naozumi Teramoto
  • Mitsuhiro Shibata
Original Paper


Ring-opening polymerizations of d-lactide, l-lactide and ɛ-caprolactone initiated from hydroxy groups of castor oil (CO) produced three kinds of branched oligomers (CODLAO, COLLAO and COCLO). The reactions of CODLAO, COLLAO and COCLO with hexamethylene diisocyanate (HDI) produced polyester–urethane networks (PUCO-scLAO/CLOs 100/0, 75/25, 50/50, 25/75 and 0/100) with different feed ratios of stereocomplex oligolactide (scLAO, that is a mixture of equal parts of COLLAO and CODLAO) and COCLO. Also, the similar reactions of COLLAO and COCLO with HDI produced homochiral networks (PUCO-LLAO/CLOs). X-ray diffraction and differential scanning calorimetry analyses revealed that stereocomplex crystallites were exclusively formed for all of the PUCO-scLAO/CLOs except for the 0/100 sample, whereas the oligo(l-lactide) segments of PUCO-LLAO/CLOs 100/0 and 75/25 did not homo-crystallize. Scanning electron microscopic analysis revealed that the compatibility for the PUCO-scLAO/CLO and PUCO-LLAO/CLO 75/25–25/75 conetworks slightly decreased with increasing CLO fraction. Dynamic mechanical analysis revealed that the lowering of storage modulus due to glassy-to-rubbery transition for PUCO-scLAO/CLOs 100/0–25/75 was much smaller than that for PUCO-LLAO/CLOs 100/0–25/75. Although the incorporation of CLO segments was effective to increase the elongation at break, the tensile strengths and moduli of the 75/25–25/75 conetworks were considerably lower than those of the 100/0 and 0/100 networks. Consequently, the 100/0 and 0/100 networks exhibited more balanced tensile properties than the 75/25–25/75 conetworks. It is noteworthy that the tensile toughnesses and elongations at break of the CO-modified 100/0 networks are much higher than those of the similar networks using glycerol instead of CO.


Castor oil Polymer network Polylactide Stereocomplex Poly(ɛ-caprolactone) Toughness 



We gratefully acknowledge financial support from the Chiba Institute of Technology. We are also grateful to Mr. Ryusuke Osada of Material Analysis Center at the Chiba Institute of Technology for assisting in the XRD analysis reported here.

Supplementary material

289_2018_2656_MOESM1_ESM.docx (544 kb)
Supplementary material 1 (DOCX 543 kb)


  1. 1.
    Cameron DJA, Shaver MP (2011) Aliphatic polyester polymer stars: synthesis, properties and applications in biomedicine and nanotechnology. Chem Soc Rev 40:1761–1776CrossRefGoogle Scholar
  2. 2.
    Wu W, Wang W, Li J (2015) Star polymers: advances in biomedical applications. Prog Polym Sci 46:55–85CrossRefGoogle Scholar
  3. 3.
    Jahandideh A, Muthukumarappan K (2017) Star-shaped lactic acid based systems and their thermosetting resins; Synthesis, characterization, potential opportunities and drawbacks. Eur Polym J 87:360–379CrossRefGoogle Scholar
  4. 4.
    Lee JS, Choo DJ, Kim SH, Kim YH (1998) Synthesis and degradation property of star-shaped polylactide. Polymer (Korea) 6:880–889Google Scholar
  5. 5.
    Lee SH, Kim SH, Han YK, Kim YH (2001) Synthesis and degradation of end-group-functionalized polylactide. J Polym Sci, Part A: Polym Chem 39:973–985CrossRefGoogle Scholar
  6. 6.
    Kim ES, Kim BC, Kim SH (2004) Structural effect of linear and star-shaped poly(l-lactic acid) on physical properties. J Polym Sci, Part B: Polym Phys 42:939–946CrossRefGoogle Scholar
  7. 7.
    Wang L, Dong CM (2006) Synthesis, crystallization kinetics, and spherulitic growth of linear and star-shaped poly(l-lactide)s with different numbers of arms. J Polym Sci, Part A: Polym Chem 44:2226–2236CrossRefGoogle Scholar
  8. 8.
    Lang M, Wong RP, Chu CC (2002) Synthesis and structural analysis of functionalized poly(ɛ-caprolactone)-based three-arm star polymers. J Polym Sci, Part A: Polym Chem 40:1127–1141CrossRefGoogle Scholar
  9. 9.
    Shi M, Zhang H, Chen J, Wan X, Zhou Q (2004) Synthesis and characterization of a novel star shapes rod-coil block copolymer. Polym Bull 52:401–408CrossRefGoogle Scholar
  10. 10.
    Wang JL, Wang L, Dong CM (2005) Synthesis, crystallization, and morphology of star-shaped poly (ɛ-caprolactone). J Polym Sci, Part A: Polym Chem 43:5449–5457CrossRefGoogle Scholar
  11. 11.
    Choi J, Kim IK, Kwak SY (2005) Synthesis and characterization of a series of star-branched poly(ɛ-caprolactone)s with the variation in arm numbers and lengths. Polymer 46:9725–9735CrossRefGoogle Scholar
  12. 12.
    Wang JL, Dong CM (2006) Physical properties, crystallization kinetics, and spherulitic growth of well-defined poly(ɛ-caprolactone)s with different arms. Polymer 47:3218–3228CrossRefGoogle Scholar
  13. 13.
    Kricheldorf HR, Lee SR (1996) Polylactones. 40. Nanopretzels by macrocyclic polymerization of lactones via a spirocyclic tin initiator derived from pentaerythritol. Macromolecules 29:8689–8695CrossRefGoogle Scholar
  14. 14.
    Kricheldorf HR, Fechner B (2002) Polylactones. LVIII. Star-shaped polylactones with functional end groups via ring-expansion polymerization with a spiroinitiator. J Polym Sci, Part A: Polym Chem 43:1047–1057CrossRefGoogle Scholar
  15. 15.
    Hao Q, Li F, Li Q, Li Y, Jia L, Yang J, Fang Q, Cao A (2005) Preparation and crystallization kinetics of new structurally well-defined star-shaped biodegradable poly(l-lactide) initiated with diverse natural sugar alcohols. Biomacromol 6:2236–2247CrossRefGoogle Scholar
  16. 16.
    Kunduru KR, Basu A, Zada MH, Domb AJ (2015) Castor oil-based biodegradable polyesters. Biomacromol 16:2572–2587CrossRefGoogle Scholar
  17. 17.
    Shibata M, Teramoto N, Kaneko K (2010) Molecular composites composed of castor oil-modified poly(ɛ-caprolactone) and self-assembled hydroxystearic acid fibers. J Polym Sci, Part B: Polym Phys 48:1281–1289CrossRefGoogle Scholar
  18. 18.
    Tsujimoto T, Haza Y, Yin Y, Uyama H (2011) Synthesis of branched poly(lactic acid) bearing a castor oil core and its plasticization effect on poly(lactic acid). Polym J 43:425–430CrossRefGoogle Scholar
  19. 19.
    Hosoda N, Lee EH, Tsujimoto T, Uyama H (2013) Phase separation-induced crystallization of poly(3-hydroxybutyrate-co-hydroxyvalerate) by branched poly(lactic acid). Ind Eng Chem Res 52:1548–1553CrossRefGoogle Scholar
  20. 20.
    Ristić IS, Marinović-Cincović M, Cakić SM, Tanasić LM, Budinski-Simendic JK (2013) Synthesis and properties of novel star-shaped polyesters based on l-lactide and castor oil. Polym Bull 70:1723–1738CrossRefGoogle Scholar
  21. 21.
    Huang S, Sun H, Sun J, Li G, Chen X (2014) Biodegradable tough blends of poly(l-lactide) and poly(castor oil)–poly(l-lactide) copolymer. Mater Lett 133:87–90CrossRefGoogle Scholar
  22. 22.
    Xie WY, Jiang N, Gan ZH (2008) Effects of multi-arm structure on crystallization and biodegradation of star-shaped poly(ɛ-caprolactone). Macromol Biosci 8:775–784CrossRefGoogle Scholar
  23. 23.
    Xy Z, Niu Y, Yang L, Xie W, Li H, Gan Z, Wang Z (2010) Morphology, rheology and crystallization behavior of polylactide composites prepared through addition of five-armed star polylactide grafted multiwalled carbon nanotubes. Polymer 51:730–737CrossRefGoogle Scholar
  24. 24.
    Teng L, Xu X, Nie W, Zhou Y, Song L, Chen P (2015) Synthesis and degradability of a star-shaped polylactide based on l-lactide and xylitol. J Polym Res 22:83. CrossRefGoogle Scholar
  25. 25.
    Teng L, Nie W, Zhou Y, Song L, Chen P (2015) Synthesis and characterization of star-shaped PLLA with sorbitol as core and its microspheres application in controlled drug release. J Appl Polym Sci. CrossRefGoogle Scholar
  26. 26.
    Goddard AR, Pérez-Nieto S, Passos TM, Quilty B, Caemichael K, Irvine DJ, Howdle SM (2016) Controlled polymerisation and purification of branched poly(lactic acid) surfactants in supercritical carbon dioxide. Green Chem 18:4772–4786CrossRefGoogle Scholar
  27. 27.
    Amsden BG (2007) Curable, biodegradable elastomers: emerging biomaterials for drug delivery and tissue engineering. Soft Matter 3:1335–1348CrossRefGoogle Scholar
  28. 28.
    Storey RF, Wiggins JS, Puckett AD (1994) Hydrolyzable poly(ester-urethane) networks from l-lysine diisocyante and d, l-lactide/ε-caprolactone homo- and copolyester triols. J Polym Sci, Part A: Polym Chem 32:2345–2363CrossRefGoogle Scholar
  29. 29.
    Amsden BG, Misra G, Gu F, Younes M (2004) Synthesis and characterization of a photo-cross-linked biodegradable elastomer. Biomacromol 5:2479–2486CrossRefGoogle Scholar
  30. 30.
    Karikari A, Edwards WF, Mecham JB, Long TE (2005) Influence of peripheral hydrogen bonding on the mechanical properties of photo-cross-linked star-shaped poly(d, l-lactide) networks. Biomacromol 6:2866–2874CrossRefGoogle Scholar
  31. 31.
    Nagata M, Sato Y (2005) Synthesis and properties of photocurable biodegradable multiblock copolymers based on pol(ε-caprolactone) and pol(l-lactide) segments. J Polym Sci, Part A: Polym Chem 43:2426–2439CrossRefGoogle Scholar
  32. 32.
    Chang SK, Zeng C, Li J, Ren J (2012) Synthesis of polylactide-based thermoset resin and its curing kinetics. Polym Int 61:1492–1502CrossRefGoogle Scholar
  33. 33.
    Bakare FO, Skrifvars M, Åkesson D, Wang Y, Afshar SJ, Esmaeili N (2014) Synthesis and characterization of bio-based thermosetting resins from lactic acid and glycerol. J Appl Polym Sci. CrossRefGoogle Scholar
  34. 34.
    Jahandideh A, Esmaeili N, Muthukumarappan K (2017) Effect of lactic acid chain length on thermomechanical properties of star-LA-Xylitol resins and jute reinforced biocompoistes. Polym Int 66:1021–1030CrossRefGoogle Scholar
  35. 35.
    Fujigasaki J, Shibata M (2015) Toughening of poly(L-lactode) by polyester-urethane networks based on castor oil-modified ɛ-caprolactone oligomers. J Polym Res 22:215. CrossRefGoogle Scholar
  36. 36.
    Shibita A, Kawasaki S, Shimasaki T, Teramoto N, Shibata M (2016) Stereocomplexation in copolymer networks incorporating enantiomeric glycerol-based 3-armed lactide oligomers and a 2-armed ɛ-caprolactone oligomer. Materials 9:519. CrossRefGoogle Scholar
  37. 37.
    Isono T, Kondo Y, Otsuka I, Nishiyama Y, Borsali R, Kakuchi T, Satoh T (2013) Synthesis and stereocomplex formation of star-shaped stereoblock polylactides consisting of poly(l-lactide) and poly(d-lactide) arm. Macromolecules 46:8509–8518CrossRefGoogle Scholar
  38. 38.
    Patrício T, Bártolo B (2013) Thermal stability of PCL/PLA blends produced by physical blending process. Procedia Eng 59:292–297CrossRefGoogle Scholar
  39. 39.
    Dusek K, Spirkova M, Havlicek I (1990) Network formation of polyurethanes due to side reactions. Macromolecules 23:1774–1781CrossRefGoogle Scholar
  40. 40.
    Pant HR, Neupane MP, Pant B, Panthia G, Oh HJ, Lee MH, Kim HY (2011) Fabrication of highly porous poly (ɛ-caprolactone) fibers for novel tissue scaffold via water-bath electrospinning. Colloids Surf B 88:587–592CrossRefGoogle Scholar
  41. 41.
    Woo EM, Chang L (2011) Crystallization and morphology of stereocomplexes in nonequimolar mixtures of poly(l-lactic acid) with excess poly(d-lactic acid). Polymer 52:6080–6089CrossRefGoogle Scholar
  42. 42.
    Shibita A, Takase H, Shibata M (2014) Semi-interpenetrating polymer networks composed of poly(l-lactide) and diisocyanate-bridged 4-arm star-shaped ɛ-caprolactone oligomers. Polymer 55:5407–5416CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Life and Environmental Sciences, Faculty of EngineeringChiba Institute of TechnologyNarashinoJapan

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