Simultaneous Biaxial Stretching of PP Resins of Varying Tacticity

Abstract The melting and simultaneous biaxial stretching behavior of three Ziegler-Natta isotactic polypropylene resins of varying isotacticity was studied. DSC melting experiments showed that the crystallinity and melt stability of the crystalline phase depend strongly on tacticity and on the degree of undermelting, ΔT = Tm – T, where Tm is the melting temperature. The level of biaxial yield stress depends on the fraction of residual “unmolten” crystallinity and the crystallite size. For specimens with same thermal history, the post-yield deformation shows strong dependence on the degree of undermelting, ΔT. The deformation homogeneity and the resulting film thickness may be related to the thermal mobility of the chains and the tie chain and entanglement densities.

[1]  J. Rieger,et al.  Role of the entangled amorphous network in tensile deformation of semicrystalline polymers. , 2003, Physical review letters.

[2]  M. Kamal,et al.  Simultaneous biaxial deformation behavior of isotactic polypropylene films , 2003 .

[3]  Heh Han Meijer,et al.  On the origin of strain hardening in glassy polymers , 2003 .

[4]  R. Phillips,et al.  Structure, processing, morphology, and property relationships of biaxially drawn Ziegler–Natta/metallocene isotactic polypropylene film , 2001 .

[5]  D. Salem,et al.  Wood and Cellulosic Chemistry , 2001 .

[6]  J. Haudin,et al.  Shear-induced crystallization of polypropylene: Influence of molecular weight , 2000 .

[7]  M. Gahleitner,et al.  Effects of the catalyst system on the crystallization of polypropylene , 1999 .

[8]  Aiko Hanyu,et al.  Properties and Film Applications of Metallocene-Based Isotactic Polypropylenes , 1999 .

[9]  Bertrand Fillon,et al.  Plastic deformation of polypropylene in relation to crystalline structure , 1999 .

[10]  Koji Yamada,et al.  Isotacticity dependence of spherulitic morphology of isotactic polypropylene , 1998 .

[11]  Y. Bertin,et al.  Influence of thermal treatment on the structure of an isotactic polypropylene , 1998 .

[12]  A. Donald,et al.  Time resolved simultaneous small- and wide-angle X-ray scattering during polyethylene deformation—II. Cold drawing of linear polyethylene , 1998 .

[13]  S. Piccarolo,et al.  The X-ray determination of the amounts of the phases in samples of isotactic poly(propylene) quenched from the melt at different cooling rates , 1997 .

[14]  E. Bullock,et al.  High-performance films from new technology polypropylene , 1996 .

[15]  R. Young,et al.  The effect of annealing on the structure and properties of isotactic polypropylene films , 1995 .

[16]  P. Canton,et al.  Determining the degree of crystallinity in semicrystalline materials by means of the Rietveld analysis , 1995 .

[17]  C. Paulik,et al.  Influence of molecular structure on crystallization behaviour and mechanical properties of polypropylene , 1995 .

[18]  D. Petit,et al.  Microstructure of quenched and annealed films of isotactic polypropylene , 1995, Journal of Materials Science.

[19]  G. R. Brown,et al.  The structure of the mesomorphic phase of quenched isotactic polypropylene , 1994 .

[20]  A. Argon,et al.  Structure and plastic deformation of polyethylene , 1994 .

[21]  R. N. Haward,et al.  Strain hardening of thermoplastics , 1993 .

[22]  A. Thierry,et al.  Self‐nucleation and recrystallization of isotactic polypropylene (α phase) investigated by differential scanning calorimetry , 1993 .

[23]  A. Lehtinen,et al.  Thermal behaviour of polypropylene fractions: 1. Influence of tacticity and molecular weight on crystallization and melting behaviour , 1993 .

[24]  A. Rudin,et al.  Persistence of regions with high segment density in polyethylene melts , 1992 .

[25]  V. Vittoria,et al.  Crystallinity of isotactic polypropylene films annealed from the quenched state , 1992, Journal of Materials Science.

[26]  J. Varga.  Supermolecular structure of isotactic polypropylene , 1992, Journal of Materials Science.

[27]  Stephen Z. D. Cheng,et al.  Isotacticity effect on crystallization and melting in polypropylene fractions: 3. Overall crystallization and melting behaviour , 1992 .

[28]  Stephen Z. D. Cheng,et al.  Isotacticity effect on crystallization and melting in polypropylene fractions. II. Linear crystal growth rate and morphology study , 1991 .

[29]  Stephen Z. D. Cheng,et al.  Isotacticity effect on crystallization and melting in polypropylene fractions: 1. Crystalline structures and thermodynamic property changes , 1991 .

[30]  D. R. Burfield,et al.  The use of infrared spectroscopy for determination of polypropylene stereoregularity , 1988 .

[31]  L. Mandelkern,et al.  Influence of structural and morphological factors on the mechanical properties of the polyethylenes , 1987 .

[32]  G. Guerra,et al.  On the structure of the quenched mesomorphic phase of isotactic polypropylene , 1986 .

[33]  I. Ward,et al.  The influence of morphology and molecular weight on ductile-brittle transitions in linear polyethylene , 1983 .

[34]  M. Takayanagi,et al.  Relationship between orientation of amorphous chains and modulus in highly oriented polypropylene , 1981 .

[35]  D. Y. Yoon,et al.  Molecular morphology in semicrystalline polymers , 1978 .

[36]  B. Wunderlich.  Crystal nucleation, growth, annealing , 1976 .

[37]  Robert J. Young,et al.  Deformation mechanisms in crystalline polymers , 1974 .

[38]  A. Peterlin,et al.  Molecular model of drawing polyethylene and polypropylene , 1971 .

[39]  G. Celotti,et al.  The structural effects of annealing time and temperature on the paracrystal‐crystal transition in isotactic polypropylene , 1969 .

[40]  J. Sauer,et al.  Effects of thermal history on isotactic polypropylene , 1968 .

[41]  P. Geil,et al.  Morphology of quenched polypropylene , 1968 .

[42]  A. T. Jones,et al.  Crystalline forms of isotactic polypropylene , 1964 .

[43]  P. Hermans,et al.  On the determination of the crystalline fraction of isotactic polypropylene from x‐ray diffraction , 1961 .

[44]  B. Warren.  X‐Ray Diffraction Methods , 1941 .