Kawasaki, Japan
Kawasaki, Japan

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Li Z.,University of Akron | Miyoshi T.,University of Akron | Sen M.K.,State University of New York at Stony Brook | Koga T.,State University of New York at Stony Brook | And 2 more authors.
Macromolecules | Year: 2013

The order-disorder phenomenon and spatial heterogeneity of chain packing, partitions of stereodefects, and molecular dynamics of α form of isotactic polypropylene (iPP) samples, which are synthesized by Zieglar-Natta catalysts, are investigated by solid-state (SS) NMR. High-resolution 13C NMR under high-power TPPM decoupling at field strengths of 110 kHz allows observation of the order-disorder phenomenon in the chain-packing structures of α form. High isotacticity samples (isotacticity at pentad level, âŸ̈mmmm⟩ = 99.4%) give a maximum ordered packing (α2) fraction of 66% at crystallization temperature (Tc) of 155 C while low stereoregularity samples (âŸ̈ mmmm⟩ = 91.0%) have only 47% at the same Tc. However, Mw (58.7-982 kg/mol) does not play a significant role in ordered packing formation. Using 13C-labeled CH3 of iPP, direct spatial correlations between the α2 and α1 structures are investigated by 13C detection of two-dimensional (2D) 1H-1H spin-diffusion (CHHC) experiments. The time dependence of the spin-diffusion polarization transferred signal intensities determines the average domain size of the α1 and α2 structures of iPP crystallized at 150 C, which was found to be 40 nm under an assumption of 2D spin diffusion. Additionally, the 13C filter CPMAS NMR spectrum on 13C CH 3-labeled iPP demonstrates that chemical defect is almost excluded from the crystalline region at Tc = 150 C (defect free crystal) while ca. 2% is in melt quench sample. Moreover, 13C centerband-only detection of exchange experiments on α2-rich sample with highest âŸ̈mmmm⟩ = 99.4% indicate that crystalline dynamics follows a single Arrhenius plot with an activation energy of 116 kJ/mol across reported order-disorder transition temperatures (157-159 C). © 2013 American Chemical Society.


Kajioka H.,Hiroshima University | Yamada K.,SunAllomer Ltd. | Taguchi K.,Hiroshima University | Toda A.,Hiroshima University
Polymer | Year: 2011

Molecular weight dependence of growth and morphology of spherulites of isotactic poly(butene-1), iPB-1, and those of the mixtures with atactic poly(butene-1), aPB-1, were examined by atomic force microscopy (AFM) and polarizing optical microscopy (POM) in order to examine the mechanism of the structural evolution by the branching and re-orientation of lamellar crystals at the growth front. The width of lamellar crystals and the characteristic size of the inner structure of spherulites decreased with increasing molecular weight. The result suggests that the mobility of the melt determines the sizes in spherulites and supports the growth front instability induced by a gradient triggering the branching. The sizes in the mixtures also decreased with increasing weight-averaged molecular weight, M w. The size dependence in low M w region, however, was too strong and that in high M w was too weak in comparison with the predicted dependence for the prepared M w. It has been concluded that the peculiar behaviors should be discussed with effective M w influenced by the occurrence of separation and exclusion of non-crystallizing aPB-1 at the growth front. © 2011 Elsevier Ltd. All rights reserved.


Patent
Sunallomer Ltd. and Hiroshima University | Date: 2011-10-07

A method for secondary-molding a polymer nano oriented crystal material in accordance with an embodiment of the present invention includes the steps of: heating the polymer nano oriented crystal material so that the polymer nano oriented crystal material changes into a mobile phase or a melt having a dense entanglement network structure; molding the polymer nano oriented crystal material which changed into the mobile phase or the melt including the dense entanglement network in the step; and cooling the polymer nano oriented crystal material, which has undergone the step, until the polymer nano oriented crystal material changes into an ordered phase.


Patent
Hiroshima University and SunAllomer Ltd. | Date: 2013-08-14

A method for secondary-molding a polymer nano oriented crystal material in accordance with the present invention includes the steps of: (1) heating the polymer nano oriented crystal material so that the polymer nano oriented crystal material changes into (a) a mobile phase or (a) a melt having a dense entanglement network structure; (2) molding the polymer nano oriented crystal material which changed into (a) the mobile phase or (b) the melt including the dense entanglement network in the step (1); and (3) cooling the polymer nano oriented crystal material, which has undergone the step (2), until the polymer nano oriented crystal material changes into an ordered phase.


Patent
Hiroshima University and Sun Allomer Ltd | Date: 2011-11-30

A polymer sheet according to the present invention is a polymer sheet whose main component is oriented nanocrystals of a polymer, and which satisfies the following conditions (I), (II), and (III): (I) having a crystallinity of not less than 70 %; (II) having a tensile strength at break of not less than 100 MPa and a tensile modulus of not less than 3 GPa; and (III) having an average thickness of not less than 0.15 mm. According to the present invention, it is possible to provide a polymer sheet excelling in properties such as mechanical strength, heat tolerance, and haze (transparency), particularly a polymer sheet having excellent properties such as mechanical strength, heat tolerance, and haze (transparency) in general-purpose plastics such as polypropylene.


Patent
Sunallomer Ltd. and Hiroshima University | Date: 2010-01-21

A polymer sheet according to at least one embodiment of the present invention is a polymer sheet whose main component is oriented nanocrystals of a polymer, and which satisfies the following conditions (I), (II), and (III): (I) having a crystallinity of not less than 70%; (II) having a tensile strength at break of not less than 100 MPa and a tensile modulus of not less than 3 GPa; and (III) having an average thickness of not less than 0.15 mm. According to at least one embodiment of the present invention, it is possible to provide a polymer sheet excelling in properties such as mechanical strength, heat tolerance, and transparency, particularly a polymer sheet having excellent properties such as mechanical strength, heat tolerance, and transparency in general-purpose plastics such as polypropylene.


The flame retardant of the present invention has a flame retardant (a) component, comprising 50 to 97% by mass of a metal hydrate (a-1) component and 3 to 50% by mass of a filler (a-2) component, wherein the filler (a-2) component contains SiO_(2), Al_(2)O_(3) and M_(2/n)O. Here, the total of the metal hydrate (a-1) component and the filler (a-2) component is 100% by mass, M represents one or more metal elements selected from a group consisting of K, Na, Mg, Ca, Fe and Zn, and n represents a valence of the metal element. According to the present invention, it is possible to provide a flame retardant capable of providing a molded article and an electric wire with a coating, which are excellent in flame retardancy, abrasion resistance and flexibility, and also have sufficient mechanical strength at low cost.


A process and apparatus for manufacturing a crystalline resin film or sheet. This manufacturing apparatus includes: an extruder that melts crystalline resin while supplying it; a gear pump that is provided on the downstream side of the extruder; a die which is provided on the downstream side of the gear pump, and which has a slit-shaped aperture; a cooling apparatus which cools film-shaped or sheet-shaped crystalline resin (A) discharged in a melted state from the die to a temperature which is not less than the crystallization temperature but not more than the melting point; and a pair of pinch rolls that press-roll between them the film-shaped or sheet-shaped crystalline resin (B) which has passed through the cooling apparatus (40), wherein the pair of guide rolls are positioned such that the thickness of the film-shaped or sheet-shaped crystalline resin (B) which has passed through the cooling apparatus is between 1.3 and 8.0 times the thickness of the film or sheet (C, D) after it has been press-rolled.


The present invention is a process and apparatus for manufacturing a crystalline resin film or sheet. This manufacturing apparatus includes: an extruder (10) that melts crystalline resin while supplying it; a gear pump (20) that is provided on the downstream side of the extruder (10); a die (30) which is provided on the downstream side of the gear pump (20), and which has a slit-shaped aperture; a cooling apparatus (40) which cools film-shaped or sheet-shaped crystalline resin (A) discharged in a melted state from the die (30) to a temperature which is not less than the crystallization temperature but not more than the melting point; and a pair of pinch rolls (50a, 50b) that press-roll between them the film-shaped or sheet-shaped crystalline resin (B) which has passed through the cooling apparatus (40), wherein the pair of guide rolls (50a, 50b) are positioned such that the thickness of the film-shaped or sheet-shaped crystalline resin (B) which has passed through the cooling apparatus (40) is between 1.3 and 8.0 times the thickness of the film or sheet (C, D) after it has been press-rolled.


Patent
Sunallomer Ltd. | Date: 2012-07-03

The purpose of the present invention is to produce an alpha-olefin polymer having excellent production stability utilizing a long-lasting high catalytic activity. Provided is a method for producing an alpha-olefin polymer using a catalyst comprising:

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