Crystallization behavior of poly(lactic acid) with a self-assembly aryl amide nucleating agent probed by real-time infrared spectroscopy and X-ray diffraction

2017 ◽  
Vol 64 ◽  
pp. 12-19 ◽  
Author(s):  
Huanhuan Zhang ◽  
Songjie Wang ◽  
Shaoyuan Zhang ◽  
Ruixue Ma ◽  
Yaming Wang ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Infrared Spectroscopy ◽  
Real Time ◽  
Self Assembly ◽  
Crystallization Behavior ◽  
Nucleating Agent ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
X Ray

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.

Crystallization Behaviors of Plasticized Poly(Lactic Acid)/Microcrystalline Cellulose Composite Sheet

2020 ◽  
Vol 856 ◽  
pp. 303-308
Author(s):  
Suttinun Phongtamrug ◽  
Sirisart Ouajai
Keyword(s):  
Lactic Acid ◽  
Microcrystalline Cellulose ◽  
Testing Machine ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Twin Screw

Poly(lactic acid) (PLA) is a potential biodegradable polymer to replace petroleum-based plastic, however, its main drawback is brittleness because of slow crystallization rate. To overcome this limitation, compounding with some additives is the most chosen choice due to easy and effective preparation. In this study, an epoxidized soybean oil (ESO) and a microcrystalline cellulose (MCC) were applied as a plasticizer and a nucleating agent, respectively. The PLA was compounded with ESO and MCC by using a twin-screw extruder. The product sheets were prepared by using a chill-roll cast film extruder. Change of thermal property after adding ESO and MCC was investigated by a differential scanning calorimeter. Mechanical property of the prepared sheet was carried out by using a universal testing machine in a tensile mode. Microstructure of the sheets was also studied by wide angle X-ray diffraction (WAXD) and small angle X-ray scattering (SAXS) techniques. The results showed that ESO assisted plasticization while the MCC induced crystallization of PLA. Also, ESO and MCC eased flowability and alignment of PLA microstructure in machine direction.

scholarly journals Hemp Fibre Reinforced Poly(Lactic Acid) Composites

2007 ◽  
Vol 29-30 ◽  
pp. 337-340 ◽  
Author(s):  
M.A. Sawpan ◽  
K.L. Pickering ◽  
Alan Fernyhough
Keyword(s):  
Lactic Acid ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Hemp Fibre ◽  
Reinforcing Material ◽  
Fibre Loading ◽  
The Degree Of Crystallinity

The potential of hemp fibre as a reinforcing material for Poly(lactic acid) (PLA) was investigated. Good interaction between hemp fibre and PLA resulted in increases of 100% for Young’s modulus and 30% for tensile strength of composites containing 30 wt% fibre. Different predictive ‘rule of mixtures’ models (e.g. Parallel, Series and Hirsch) were assessed regarding the dependence of tensile properties on fibre loading. Limited agreement with models was observed. Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) studies showed that hemp fibre increased the degree of crystallinity in PLA composites.

Characterization of Electrospun Poly(Lactic Acid)/polyaniline Blend Nanofibers

2011 ◽  
Vol 332-334 ◽  
pp. 317-320 ◽  
Author(s):  
Hui Qin Zhang
Keyword(s):  
Lactic Acid ◽  
Composite Nanofibers ◽  
Weight Ratio ◽  
Electrospinning Process ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Ft Ir

In this study, composite nanofibers of polyaniline doped with dodecylbenzene sulfonic acid (PANI-DBSA) and Poly(lactic acid) (PLA) were prepared via an electrospinning process. The surface morphology, thermal properties and crystal structure of PLA/PANI-DBSA nanofibers are characterized using Fourier transform infrared spectroscopy (FT-IR), wide-angle x-ray diffraction (WAXD) and scanning electron microscopy (SEM). SEM images showed that the morphology and diameter of the nanofibers were affected by the weight ratio of blend solution.

Molecular Cocrystals of Carboxylic Acids. XXVI Adducts of the Amino-Substituted Benzoic Acids with Nitroaromatic Lewis Bases: the Influence of Associative Polyfunctional Substituents on Self-Assembly of Molecules in Cocrystallization Processes

1997 ◽  
Vol 50 (10) ◽  
pp. 977 ◽  
Author(s):  
Daniel E. Lynch ◽  
Graham Smith ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectroscopy ◽  
Self Assembly ◽  
Benzoic Acids ◽  
Aminobenzoic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lewis Bases ◽  
Aminobenzoic Acids ◽  
Substituted Benzoic Acids

A series of molecular adducts of the isomeric aminobenzoic acids with the nitro-substituted Lewis bases 2-chloro-5-nitropyridine, 5-nitroquinoline and 5-nitroisoquinoline has been prepared and characterized by using infrared spectroscopy and X-ray powder diffraction, and in four cases by single-crystal X-ray diffraction methods. These four compounds are the adducts of 3-aminobenzoic acid with 5-nitroquinoline [(C7H7NO2)(C9H6N2O2)], 4-aminobenzoic acid with 5-nitroquinoline [(C7H7NO2)2(C9H6N2O2)], 2-aminobenzoic acid with 5-nitroisoquinoline [(C7H7NO2)(C9H6N2O2)] and 4-aminobenzoic acid with 5-nitroisoquinoline [(C7H7N2O2)(C9H6N2O2)]. Other compounds described are the (1 : 1) adducts of 4-aminobenzoic acid with 2-chloro-5-nitropyridine, and 2-aminobenzoic acid with 5-nitroquinoline. All adducts involve hydrogen-bonding network associations while in none of the examples is any proton transfer involved.

Crystallization Characteristics Of Phase Change Nanoparticle Arrays Fabricated By Self-Assembly Based Lithography

2008 ◽  
Vol 1072 ◽  
Author(s):  
Yuan Zhang ◽  
Simone Raoux ◽  
Daniel Krebs ◽  
Leslie E. Krupp ◽  
Teya Topuria ◽  
...  
Keyword(s):  
Phase Change ◽  
Self Assembly ◽  
Crystallization Behavior ◽  
Small Scale ◽  
Nanoparticle Arrays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Nanodot Arrays ◽  
Patterned Materials

ABSTRACTPhase change nanodot arrays were fabricated using self-assembly diblock copolymer template PS-b-PMMA (polystyrene-poly (methyl-methacrylate)) and studied by time resolved X-ray diffraction. The size of the nanodots was less than 15nm in diameter with 40nm spacing. This method is quite flexible regarding the patterned materials, and can be used on different substrates. The crystallization behavior of small scale phase change nanodot arrays was studied for different materials, such as Ge15Sb85, Ge2Sb2Te5 and Ag and In doped Sb2Te. It was found that the nanodots had higher crystallization temperatures compared to their corresponding blanket films and crystallized over a broader temperature range.

Crystallization behavior studied by synchrotron small-angle X-ray scattering of poly (lactic acid)/cellulose nanofibers composites

2017 ◽  
Vol 143 ◽  
pp. 106-115 ◽  
Author(s):  
Thanh Chi Nguyen ◽  
Chaiwat Ruksakulpiwat ◽  
Supagorn Rugmai ◽  
Siriwat Soontaranon ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Lactic Acid ◽  
Small Angle ◽  
Crystallization Behavior ◽  
Cellulose Nanofibers ◽  
Poly Lactic Acid ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Composites Based on Poly(Lactic Acid) (PLA) and SBA-15: Effect of Mesoporous Silica on Thermal Stability and on Isothermal Crystallization from Either Glass or Molten State

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2743
Author(s):  
Tamara M. Díez-Rodríguez ◽  
Enrique Blázquez-Blázquez ◽  
Ernesto Pérez ◽  
María L. Cerrada
Keyword(s):  
Lactic Acid ◽  
Mesoporous Silica ◽  
Isothermal Crystallization ◽  
Physical Aging ◽  
Glassy State ◽  
Poly Lactic Acid ◽  
Molten State ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Several composites based on an L-rich poly(lactic acid) (PLA) with different contents of mesoporous Santa Barbara Amorphous (SBA-15) silica were prepared in order to evaluate the effect of the mesoporous silica on the resultant PLA materials by examining morphological aspects, changes in PLA phases and their transitions, and, primarily, the influence on some final properties. Melt extrusion was chosen for the obtainment of the composites, followed by quenching from the melt to prepare films. Completely amorphous samples were then attained, as deduced from X-ray diffraction and differential scanning calorimetry (DSC) analyses. Thermogravimetric analysis (TGA) results demonstrated that the presence of SBA-15 particles in the PLA matrix did not exert any significant influence on the thermal decomposition of these composites. An important nucleation effect of the silica was found in PLA, especially under isothermal crystallization either from the melt or from its glassy state. As expected, isothermal crystallization from the glass was considerably faster than from the molten state, and these high differences were also responsible for a more considerable nucleating role of SBA-15 when crystallizing from the melt. It is remarkable that the PLA under analysis showed very close temperatures for cold crystallization and its subsequent melting. Moreover, the type of developed polymorphs did not accomplish the common rules previously described in the literature. Thus, all the isothermal experiments led to exclusive formation of the α modification, and the observation of the α’ crystals required the annealing for long times at temperatures below 80 °C, as ascertained by both DSC and X-ray diffraction experiments. Finally, microhardness (MH) measurements indicated a competition between the PLA physical aging and the silica reinforcement effect in the as-processed amorphous films. Physical aging in the neat PLA was much more important than in the PLA matrix that constituted the composites. Accordingly, the MH trend with SBA-15 content was strongly dependent on aging times.

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