Abstract
The spherulites of the short carbon fiber(SCF)/poly (trimethylene terephthalate) (PTT) composites formed in limited space at designed temperatures, and their melting behaviors were studied by the polarized optical microscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM), respectively. The results suggest that SCF content, isothermal crystallization temperatures, and the film thicknesses influence the crystal morphology of the composites. The dimension of the spherulites is decreased with increasing SCF content, but whether banded or nonbanded spherulites will form in the composites is not dependent on SCF content. However, the crystal morphology of the composites depends strongly on the temperature. When the isothermal crystallization temperatures increase from 180°C to 230°C, the crystal morphology of SCF/PTT composites continuously changes in the following order: nonbanded → banded → nonbanded spherulites. Discontinuous circle lines form in the film when the film thickness increases from 30 to 60 μm. Basing on the SEM observation, it is found that these circle lines are cracks formed due to the constriction difference of the different parts of the spherulites. These cracks are formed when the film is cooled from the isothermal crystallization temperature to the room temperature at a slow cooling rate; while they will disappear gradually at different temperatures in the heating process. The crack will appear/disappear first around the center of the spherulite when the film was cooled/heated. The nontwisted or slightly twisted lamellas will reorganize to form highly twisted lamellas inducing apparent banded texture of the spherulites.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
Ho R M, Ke K Z, Chen M. Crystal structure and banded spherulite of poly(trimethylene terephthalate). Macromolecules, 2000, 33: 7529–7535
Yun J H, Kuboyama K, Chiba T, Ougizawa T. Crystallization temperature dependence of interference color and morphology in poly(trimethylene terephthalate) spherulite. Polymer, 2006, 47: 4831–4838
Chuah H H. Orientation and structure development in poly (trimethylene terephthalate) tensile drawing. Macromolecules, 2001, 34: 6985–6993
Run M T, Yao C G, Wang Y J, Gao J G. Isothermal crystallization kinetics and melting behaviors of nanocomposites of poly(trimethylene terephthalate) filled with nano-CaCO3. J Appl Polym Sci, 2007, 106: 1557–1567
Wang B J, Li C Y, Jennnifer H, Cheng S Z D, Geil P H, Grebowicz J, Ho R M. Poly(trimethylene terephthalate) crystal structure and morphology in different Length scales. Polymer, 2001, 42: 7171–7180
Chuang W T, Hong P D, Chuah H H. Effects of crystallization behavior on morphological change in poly(trimethylene terephthalate) spherulites. Polymer, 2004, 45(7): 2413–2425
Liu Z J, Chen K Q, Yan D Y. Crystallization, morphology, and dynamic mechanical properties of poly(trimethylene terephthalate)/clay nanocomposites. Euro Polym J, 2003, 39: 2359–2366
Chen J, Yang D C. Phase behavior and rhythmically grown ringbanded spherulites in blends of liquid crystalline poly(aryl ether ketone) and poly(aryl ether ether ketone). Macromolecules, 2005, 38: 3371–3379
Keith H D, Padden F J. Ringed spherulites in polyethylene. J Polym Sci, 1958, 31: 415
Schultz J M, Kinloch D R. Transverse screw dislocations: A source of twist in crystalline polymer ribbons. Polymer, 1969, 10: 271–278
Bassett D C, Hodge A M. On lamellar organization in banded spherulites of polyethylene. Polymer, 1978, 19: 469–472
Keller A., Windle A. H. The origin of banded textures induced by shear-a suggested scheme and a relevant rheological effect. J Non-Newtonian Fluid Mechanics, 1996, 67: 241–268
Keith H D, Padden F J. Twisting orientation and the role of transient states in polymer crystallization. Polymer, 1984, 25: 28–42
Keith H D, Padden F J. Banding in polyethylene and other spherulite. Macromolecules, 1996, 29: 7776
Keith H D. Banding in spherulites: two recurring topics. Polymer 2001, 42: 09987–09993
Patel D, Bassett D C. On the formation of S-profiled lamellae in polyethylene and the genesis of banded spherulites. Polymer, 2002, 43: 3795–3802
Lot B, Cheng S Z D. A critical assessment of unbalanced surface stresses as the mechanical origin of twisting and scrolling of polymer crystals. Polymer, 2005, 46: 577–610
Bassett D C. A critical assessment of unbalanced surface stresses: some complementary considerations. Polymer, 2006, 47: 3263–3266
Lot B, Cheng S Z D. Comments on: ‘a critical assessment of unbalanced surface stresses: some complementary considerations’, by DC Bassett. Polymer, 2006, 46: 3267–3270
Chen E J H, Hsiao B S. The effects of transcrystalline interphase in advanced polymer composites. Polym Eng Sci, 1992, 32: 280–287
Li T Q, Zhang M Q, Zhang K, Zeng H M. Long-range effects of carbon fiber on crystallization of semicrystalline thermoplastics. Polymer, 2000, 41: 161–168
Chi W, Liu C R. Transcrystallization of polypropylene on carbon fibers. Polymer, 1999, 40: 289–298
Sari N, Sinmazçlik T. Erosive wear behaviour of carbon fibre/polyetherimide composites under low particle speed. Mater and Design, 2007, 28: 351–355
Kaynak C, Orgun O, Tincer T. Matrix and interface modification of short carbon fiber-reinforced epoxy. Polym Test, 2005, 24: 455–462
Run M T, Song H Z, Yao C G, Wang Y J. Crystal Morphology and Nonisothermal Crystallization Kinetics of Short Carbon Fiber/Poly (trimethylene terephthalate) Composites. J Appl Polym Sci, 2007, 106: 868–877
Suryasarathi B, Arup R B, Pravin V K. Fractionated crystallization in PA6/ABS blends: Influence of a reactive compatibilizer and multiwall carbon nanotubes. Polymer, 2007, 48: 356–362
Wang Z G, Wang X H, Yu D H, Jiang B Z. The formation of ring-banded spherulites of poly(ε-caprolactone) in its miscible mixtures with poly(styrene-co-acrylonitrile). Polymer, 1997, 38: 5897–5901
Huang Y P, Luo X L, Ma D Z. Ringed spherulite morphology and compatibility in the binary blends of poly(ε-caprolactone) with ethyl cellulose. Eur Polym J, 2001, 37: 2153–2157
Bauer H, Owen A J. Some structural and mechanical properties of bacterially produced poly-β-hydroxybutyrate-co-β-hydroxyvalerate. Colloid Polym Sci, 1988, 266: 241–247
Martinez S J, Sanchez C M, Barham P J, Keller A. Thermal expansion and spherulite cracking in 3-hydroxybutyrate/3-hydroxyvalerate copolymers. J Mater Sci Lett, 1989, 8: 490–492
Ding J D, Zhu J X, Yang Y L. Banded spherulites of poly (ethylene oxide) and the concentric cracks within a single spherulite. Chem Res Chin Uni, 1996, 17(3): 489–499
Run M T, Hu X M, Gao J G. Morphology and thermal properties of the poly(lactic acid)/carboxylic polypropylene blends. Acta Polymerica Sinica, 2007, 12: 1121–1126
Xu J, Guo B H, Chen G Q. Terraces on Banded Spherulites of Polyhydroxyalkanoates. J Polym Sci: Part B: Polym Phys, 2003, 41: 2128–2134
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Run, M., Song, H. & Hao, Y. Study on the crystal morphology and melting behavior of isothermally crystallized composites of short carbon fiber and poly(trimethylene terephthalate). Front. Chem. Eng. China 3, 255–264 (2009). https://doi.org/10.1007/s11705-009-0008-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11705-009-0008-9