Crystalline form transformation of isotactic polypropylene induced by N,N’-diphenyl glutaramide

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Quliang Lu ◽  
Qiang Dou
Keyword(s):  
Polarized Light ◽  
Nucleating Agent ◽  
Maximum Amount ◽  
Crystalline Form ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Cell Parameters ◽  
Form Transformation

AbstractN,N’-Diphenyl glutaramide (DPG) is found to be an effective nucleating agent to induce the β-form of iPP. The results of wide angle X-ray diffraction, differential scanning calorimetry and polarized light microscopy indicate that 0.2 wt% of DPG can induce the maximum amount of β-form iPP, and the favorable crystallization temperature for the growth of β-form is 120 ˚C in this study. Analysis of the misfit factor between the cell parameters of DPG and β-iPP shows β-iPP can epitaxially crystallize on the bc face of DPG crystal well.

Structure and properties of polypropylene/organic rectorite nanocomposites

Clay Minerals ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Yun Huang ◽  
Xiaoyan Ma ◽  
Guozheng Liang ◽  
Hongxia Yan
Keyword(s):  
Loss Modulus ◽  
Polarized Light ◽  
Clay Content ◽  
Crystal Form ◽  
Ammonium Bromide ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Monoclinic Crystal ◽  
X Ray

AbstractMelt blending using a twin-screw extruder was used to prepare composites of polypropylene (PP)/organic rectorite (PR). The organic rectorite (OREC) was modified with dodecyl benzyl dimethyl ammonium bromide (1227). Wide-angle X-ray diffraction (WAXD) and transmission electron microscopy were used to investigate the dispersion of OREC in the composites. The d spacings of OREC in PR composites was greater than in OREC itself. The dispersion of OREC particles in the PP polymer matrix was fine and uniform when the clay content was small (2 wt.%). The rheology was characterized using a capillary rheometer. The processing behaviour of the PR system improved as the amount of OREC added increased. Non-isothermal crystallization kinetics were analysed using differential scanning calorimetry. It was shown that the addition of OREC had a heterogeneous nucleation effect on PP, and can accelerate the crystallization. However, only when fine dispersion was achieved, and at lower rates of temperature decrease, was the crystallinity greater. Wide-angle X-ray diffraction and polarized light microscopy were used to observe the crystalline form and crystallite size. The PP in the PR composites exhibited an a-monoclinic crystal form, as in pure PP, and in both cases a spherulite structure was observed. However, the smaller spherulite size in the PR systems indicated that addition of OREC can reduce the crystal size significantly, which might improve the ‘toughness’ of the PP. The mechanical properties (tensile and impact strength) improved when the amount of OREC added was appropriate. Dynamic mechanical analysis showed that the storage modulus (E′) and loss modulus (E″) of the nanocomposites were somewhat greater than those of pure PP when an appropriate amount of OREC was added. Finally, thermogravimetric analysis showed that the PR systems exhibited a greater thermal stability than was seen with pure PP.

scholarly journals Influence of Molecular Orientation on the Melting Behavior of Poly(phenylene sulfide) Fibers

2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800
Author(s):  
Prabhakar Gulgunje ◽  
Gajanan Bhat ◽  
Joseph Spruiell
Keyword(s):  
Differential Scanning Calorimetry ◽  
Molecular Orientation ◽  
Polarized Light ◽  
Melting Behavior ◽  
Probable Mechanism ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Phenylene Sulfide

The influence of molecular orientation on the melting behavior of draw-annealed poly(phenylene sulfide) fibers is investigated in the present paper. Tools used to probe the investigation were differential scanning calorimetry, polarized light optical microscopy, wide angle X-ray diffraction, and small angle X-ray diffraction. It is shown that molecular orientation in the crystalline and amorphous regions play a key role in crystal rearrangement during melting. A probable mechanism by which amorphous orientation influences crystal rearrangement is also discussed.

Investigation on β-Polypropylene/Talc Composites

2012 ◽  
Vol 182-183 ◽  
pp. 259-264
Author(s):  
Jia Wei Duan ◽  
Qiang Dou
Keyword(s):  
Polarized Light ◽  
Nucleating Agent ◽  
Mechanical Tests ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Melt Compounding ◽  
Β Phase ◽  
Α Phase ◽  
Melting And Crystallization

In this study polypropylene (PP) composites containing β-nucleating agent (NT-C) and talc filler were prepared by melt compounding. The melting and crystallization behavior, morphology and mechanical properties of the composites were studied by means of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), polarized light microscopy (PLM) and mechanical tests. The results indicate that talc suppresses the formation of β phase, but promotes the formation of α phase. The Izod notched impact strength and tensile strength of β-PP/talc composites are superior to those of PP/talc composites, indicating an outstanding balance of stiffness and toughness of β-PP/talc composites.

Crystallization Properties of Nucleated Poly(lactic acid)

2012 ◽  
Vol 549 ◽  
pp. 322-326 ◽  
Author(s):  
Yong Chen ◽  
Qiang Dou
Keyword(s):  
Lactic Acid ◽  
Crystallization Behavior ◽  
Polarized Light ◽  
Nucleating Agent ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystallization Properties ◽  
Melting And Crystallization

The effect of a nucleating agent (NT-C) on the crystallization behavior of poly(lactic acid) (PLA) was studied. The melting and crystallization behavior and spherulitic morphology of the nucleated PLA were investigated by means of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarized light microscopy (PLM). It is found that the crystallization temperature and crystallinity increase, the spherulitic size decrease for the nucleated PLA. But the crystal structure of the nucleated PLA is not changed.

scholarly journals Effect of different nucleating agent on crystallization kinetics and morphology of polypropylene

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Yanjie An ◽  
Sihan Wang ◽  
Rui Li ◽  
Dezhu Shi ◽  
Yuxin Gao ◽  
...  
Keyword(s):  
Crystallization Kinetics ◽  
Crystallization Behavior ◽  
Polarized Light ◽  
Nucleating Agent ◽  
Crystallization Time ◽  
Nucleating Agents ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Half Crystallization Time

AbstractThe effects of phosphate nucleating agent (NA), carboxylate nucleating agent (MD), rosin type nucleating agent (WA) and sorbitol nucleating agent (NX) on crystallization behavior of isotactic polypropylene were investigated by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The results showed that different structure nucleating agents significantly affected the crystallization kinetics, rate and temperature of polypropylene. Among them, half crystallization time of NX nucleating agent was the shortest, which was 53.4 seconds, and the crystallization temperature was the highest, reaching 129.8°C.

Study in performance and morphology of polyamide 12 produced by selective laser sintering technology

2018 ◽  
Vol 24 (5) ◽  
pp. 813-820 ◽  
Author(s):  
Junjie Wu ◽  
Xiang Xu ◽  
Zhihao Zhao ◽  
Minjie Wang ◽  
Jie Zhang
Keyword(s):  
Selective Laser Sintering ◽  
Polarized Light ◽  
Chain Scission ◽  
High Energy ◽  
Laser Sintering ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Content Type ◽  
X Ray ◽  
Polyamide 12

Purpose The purpose of this paper is to investigate the effect of selective laser sintering (SLS) method on morphology and performance of polyamide 12. Design/methodology/approach Crystallization behavior is critical to the properties of semi-crystalline polymers. The crystallization condition of SLS process is much different from others. The morphology of polyamide 12 produced by SLS technology was investigated using scanning electron microscopy, polarized light microscopy, differential scanning calorimetry, X-ray diffraction and wide-angle X-ray diffraction. Findings Too low fill laser power brought about bad fusion of powders, while too high energy input resulted in bad performance due to chain scission of macromolecules. There were three types of crystal in the raw powder material, denoted as overgrowth crystal, ring-banded spherulite and normal spherulite. Originality/value In this work, SLS samples with different sintering parameters, as well as compression molding sample for the purpose of comparison, were made to study the morphology and crystal structure of sintered PA12 in detail.

Thermotropic behavior of sodium cholesteryl carbonate

2009 ◽  
Vol 24 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Rabkwan Chuealee ◽  
Timothy S. Wiedmann ◽  
Teerapol Srichana
Keyword(s):  
Phase Behavior ◽  
Chemical Structure ◽  
Liquid Crystalline ◽  
Polarized Light ◽  
Wave Number ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
C Nmr

Sodium cholesteryl carbonate ester (SCC) was synthesized, and its phase behavior was studied. The chemical structure was assessed by solid-state infrared spectroscopy based on vibration analysis. The wave number at 1705 and 1276 cm−1 corresponds to a carbonyl carbonate and O–C–O stretching of SCC, respectively. Molecular structure of SCC was further investigated with 1H and 13C NMR spectroscopy. The chemical shift, for the carbonyl carbonate resonance appeared at 155.5 ppm. A molecular mass of SCC was at m/z of 452. Differential scanning calorimetry (DSC), video-enhanced microscopy (VEM) together with polarized light microscopy, and small-angle x-ray scattering (SAXS) were used to characterize the phase behavior as a function of temperature of SCC. Liquid crystalline phase was formed with SCC. Based on the thermal properties and x-ray diffraction, it appears that SCC forms a structure analogous to the type II monolayer structure observed with cholesterol esters.

scholarly journals Synthesis and Crystal Structure of the Bioinorganic Complex [Sb(Hedta)]·2H2O

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Di Li ◽  
Guo-Qing Zhong
Keyword(s):  
Crystal Structure ◽  
Ethylenediaminetetraacetic Acid ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Cell Parameters ◽  
Composition And Structure ◽  
Decomposition Processes ◽  
Distorted Trigonal Bipyramid

The antimony(III) complex [Sb(Hedta)]·2H2O was synthesized with ethylenediaminetetraacetic acid (H4edta) and antimonous oxide as main raw materials in aqueous solution. The composition and structure of the complex were characterized by elemental analysis, infrared spectra, single crystal X-ray diffraction, X-ray powder diffraction, thermogravimetry, and differential scanning calorimetry. The crystal structure of the antimony(III) complex belongs to orthorhombic system, space group Pna2(1), with cell parameters ofa=18.4823(18) Å,b=10.9408(12) Å,c=7.3671(5) Å,V=1489.7(2) Å3,Z=4, andDc=1.993 g cm−3. The Sb(III) ion is five-coordinated by two amido N atoms and three carboxyl O atoms from a single Hedta3−ligand, forming a distorted trigonal bipyramid geometry. The thermal decomposition processes of the complex include dehydration, oxidation, and pyrolysis of the ligand, and the last residue is Sb2O3at the temperature of 570°C.

Polypseudorotaxane Hydrogels Based on F127 Block-Selected Inclusion Complexation with α-Cyclodextrin

2012 ◽  
Vol 482-484 ◽  
pp. 1898-1903
Author(s):  
Ying Xue Zhou ◽  
Xiao Dong Fan ◽  
Dan Xue
Keyword(s):  
Thermal Stability ◽  
Inclusion Complex ◽  
Inclusion Complexation ◽  
Wide Angle ◽  
Acryloyl Chloride ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Thermal Stability Of ◽  
Channel Type

Supramolecular hydrogels were formed through F127, acryloyl chloride modified F127 inclusion complex with α-cyclodextrin, respectively. The structure of modified copolymers and inclusion complex was characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen nuclear magnetic resonance (1H-NMR). Hydrogels formed from supramolecular inclusion are imparted channel-type structure investigated by wide angle x-ray diffraction (WAXRD). Differential scanning calorimetry (DSC) and TG experiments showed that thermal stability of hydrogels depend on the nature of axis polymer. The relative model was proposed to elucidate the inclusion complexes and hydrogels formation.

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