Abstract
The efficiency of the degree of cooling and shear-induced crystallization on the formation of different crystal polymorphs and morphology development of isotactic polypropylene (iPP) and random propylene–ethylene copolymer was analysed in cast films. Wide-angle X-ray scattering was applied to evaluate the crystal structure formed in films solidified at different chill roll temperatures (15, 40, and 70 °C) and throughputs of the line (60 and 120 kg/h). The crystal geometry and morphology were visualized by atomic force microscopy. For films generated at 15 °C or at large supercooling together with the nodular domain additional grained round-shaped structures composed of mesophase were detected on the film surface. Increase of the chill roll temperature or lower supercooling allowed formation of the monoclinic phase of iPP. Higher drawing rate triggered crystal formation preferably on the surface of films quenched at 15 °C. The crystal structure and morphology were correlated to selected optical and mechanical properties. At close-to-identical crystallinity, the crystal aspect ratio and film roughness play a major role in controlling the film transparency and stiffness.
Similar content being viewed by others
References
Piccarolo S (1992) Morphological changes in isotactic polypropylene as a function of cooling rate. J Macromol Sci Part B Phys B31:501–505
Piccarolo S, Alessi S, Brucato V, Titomanlio G (1993) Crystallization behaviour at high cooling rates of two polypropylenes. In: Dosier M (ed) Crystallization of polymers. Dordrecht, Kluwer, pp 475–480
Zia Q, Androsch R, Radusch HJ, Piccarolo S (2006) Morphology, reorganization, and stability of mesomorphic nanocrystals in isotactic polypropylene. Polymer 47:8163–8172
De Santis F, Adamovsky S, Titomanlio G, Schick C (2006) Scanning nanocalorimetry at high cooling rate of isotactic polypropylene. Macromolecules 39:2562–2567
Gradys A, Sajkiewic P, Minakov AA, Adamovsky S, Schick C, Hashimoto T, Saijo K (2005) Crystallization of polypropylene at various cooling rate. Mat Sci Eng A413–414:442–446. https://doi.org/10.1016/j.msea.2005.08.167
Binsbergen FL, De Lange BGM (1968) Morphology of polypropylene from the melt. Polymer 9:23–40. https://doi.org/10.1016/0032-3861(68)90006-2
Bassett DC, Olley RH (1984) On the lamellar morphology of isotactic polypropylene spherulites. Polymer 25:935–943. https://doi.org/10.1016/0032-3861(84)90076-4
Mileva D, Androsch R, Zhuravlev E, Schick C (2009) Temperature of melting of the mesophase of isotactic polypropylene. Macromolecules 42(19):7275–7278
Mileva D, Androsch R (2012) Effect of co-unit type in random propylene copolymers on the kinetics of mesophase formation and crystallization. Colloid Polym Sci 290:465–471
Cavallo D, Gardella L, Alfonso GC, Mileva D, Androsch R (2012) Mesophase-mediated crystallization of poly(butylene-2,6-naphthalate): an example of Ostwald’s rule of stages. Polymer 53(20):4429–4437
Gahleitner M, Jääskeläinen P, Ratajski E, Paulik C, Reussner J, Wolfschwenger J, Neißl W (2005) Propylene–ethylene random copolymers: comonomer effects on crystallinity and application properties. J Appl Polym Sci 95:1073–1081
Lamberti G, Brucato V (2003) Real-time orientation and crystallinity measurements during the isotactic polypropylene film-casting process. J Appl Polym Sci 41:998–1008
Zia Q, Tranchida D, Androsch R, Schönerr H (2012) Effect of crystal habit and superstructure on modulus of elasticity of isotactic polypropylene by AFM nanoindentation. J Mater Sci 47:3040–3045
Zia Q, Mileva D, Androsch R (2010) Deformation behavior of isotactic polypropylene crystallized via the mesophase. Polym Bull 65:623–634
Cerrada ML, Polo-Corpo MJ, Benavente R, Perez E, Velilla T (2009) Formation of the new trigonal polymorph in iPP–1-hexene copolymers. Competition with the mesomorphic phase. Macromolecules 42:702–708
Mileva D, Androsch R, Radusch HJ (2008) Effect of cooling rate on melt-crystallization of random propylene–ethylene and propylene-1-butene copolymers. Polym Bull 61:643–654
Cavallo D, Azzurri F, Floris R, Alfonso GC, Balzano L, Peters GW (2010) Continuous cooling curves diagrams of propene/ethylene random copolymers. The role of ethylene counits in mesophase development. Macromolecules 43:2890–2896
Aniunoh K, Harrison G (2010) The processing of polypropylene cast films. I. Impact of material properties and processing conditions on film formation. Polym Eng Sci 50:1151–1160. https://doi.org/10.1002/pen.21637
Sadeghi F, Tabatabaei SH, Ajji A, Carreau PJ (2010) Properties of uniaxial stretched polypropylene films: effect of drawing temperature and random copolymer content. Can J Chem Eng 88:1091–1098. https://doi.org/10.1002/cjce.20372
Tabatabaei S, Abdellah A (2011) Effect of initial crystalline morphology on properties of polypropylene cast films. J Plast Film Sheeting 27:223–233. https://doi.org/10.1177/8756087911407921
Cimmino S, Martuscelli E, Nicolais L, Silvestre C (1978) Thermal and mechanical properties of isotactic random propylene–butene-1-copolymer. Polymer 19:1222–1223
Marega C, Marigo A, Saini R, Ferrari P (2001) The influence of thermal treatment and processing on the structure and morphology of poly(propylene-ran-1-butene) copolymers. Polym Int 50:442–448
Resch K, Wallner G, Teichert C, Maier G, Gahleitner M (2006) Optical properties of highly transparent polypropylene cast films: influence of material structure, additives, and processing conditions. Polym Eng Sci 46:520–531
Gahleitner M, Grein C, Blell R, Wolfschwenger J, Koch T, Ingolic E (2011) Sterilization of propylene/ethylene random copolymers: annealing effects on crystalline structure and transparency as influenced by polymer structure and nucleation. Exp Polym Lett 5:788–798
Meng X, Shijun Z, Jieying L, Hui Q, Jianyeiu L, Hongwei S, Dali G, Jie L (2014) Influences of processing on the phase transition and crystallization of polypropylene cast films. J Appl Polym Sci 41100:1–9. https://doi.org/10.1002/APP.41100
Resconi L (1999) Synthesis of atactic poly(propylene) using metallocene catalysts. In: Kaminsky W, Scheirs J (eds) Metallocene based polyolefins, vol 1. Wiley, New York, pp 467–484
Willmouth FM (1986) Transparency, translucency, and gloss. In: Meeten GH (ed) Optical properties of polymers. Elsevier, London
Mileva D, Gahleitner M, Gloger D (2016) In: AIP conference proceedings vol. 1736, p 020069. https://doi.org/10.1063/1.4949644
De Rosa C, Auriemma F, Di Girolamo R, Romano L, De Luca MR (2010) A new mesophase of isotactic polypropylene in copolymers of propylene with long branched comonomers. Macromolecules 43:8559–8569
Humbert S, Lame O, Seguela R, Vigier G (2011) A re-examination of the elastic modulus dependence on crystallinity in semi-crystalline polymers. Polymer 52:4899–4909
Bédoui F, Diani J, Régnier G (2004) Micromechanical modeling of elastic properties in polyolefins. Polymer 45:2433–2442
Popli R, Mandelkern L (1987) Influence of structural and morphological factors on the mechanical properties of the polyethylenes. J Polym Sci Part B Polym Phys 25:441–483
Mileva D, Androsch R, Radusch H-J (2009) Effect of structure on light transmission in isotactic polypropylene and random propylene-1-butene copolymers. Polym Bull 62(4):561–571
Gahleitner M, Mileva D, Gloger D, Androsch R, Tranchida D (2017) Polymer structure effects on crystallization and properties in polypropylene film casting. In: AIP conference proceedings vol. 1914. https://doi.org/10.1063/1.5016762
Acknowledgements
The authors would like to acknowledge Walter Schaffer for the AFM images.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Mileva, D., Gahleitner, M., Gloger, D. et al. Crystal structure: a way to control properties in cast films of polypropylene. Polym. Bull. 75, 5587–5598 (2018). https://doi.org/10.1007/s00289-018-2343-9
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00289-018-2343-9