A Comparative Study on the Effect of Adiabatic Extrusion by Twin-Screw Extruder to the Crystallization Pattern and Thermal Behavior of Polyamide 6/C20A Nanocomposites

2013 ◽  
Vol 756 ◽  
pp. 135-142 ◽  
Author(s):  
Zulhelmi Ismail ◽  
Kamal Yusoh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Degradation ◽  
Polyamide 6 ◽  
Combination Effect ◽  
Gravimetric Analysis ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Mass Losses ◽  
Twin Screw

The performance of an adiabatic extrusion in minimizing the risk of thermal degradation for PA6/C20A nanocomposites was investigated in this paper. The screw speed of twin-screw extruder was maintained at constant value of 100 RPM while the clay loadings C20A were varied between 1 wt %, 3wt % and 5 wt % respectively.Thermal gravimetric analysis was used to characterize the thermal property of polyamide6/C20A-nanocomposites and the crystallization pattern was thoroughly examined via the application of differential scanning calorimetry. The time taken for 10 wt.% mass losses of majority adiabatic extruded samples was observed to be longer as compared to the conventional extruded PA6/C20A samples. The combination effect of adiabatic extrusion and nanoclay presence in the PA6-matrix has managed to increase thermal resistant of PA6. The crystallinity grade for each of the samples with different loading of C20A. however has not diversed in value since the index of crystallinity (Xc) remains independent of C20-volume althoughconventional/adiabatic setting of extruder could possibly have greater effect on the crystalline feature of PA6/C20A nanocomposites.

Effect of different extrusion methods on physicochemical properties and qualities of noodles based on rice flour

2021 ◽  
pp. 108201322110692
Author(s):  
Nispa Seetapan ◽  
Bootsrapa Leelawat ◽  
Nattawut Limparyoon ◽  
Rattana Yooberg
Keyword(s):  
Moisture Content ◽  
Rice Flour ◽  
Extrusion Process ◽  
Scanning Electron Micrographs ◽  
Twin Screw Extruder ◽  
Capillary Rheometer ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Thermomechanical Processes

Rice noodles have been manufactured in the food industry using different extrusion methods, such as traditional and modern extrusions, which affect the noodle structure and qualities. Therefore, the effects of the extrusion process on qualities of rice noodles using the same blend of rice flour and crosslinked starch were evaluated. In this study, a capillary rheometer was used as an alternative approach to simulate the traditional extrusion method in which the noodles are obtained by continuously pressing the pregelatinized noodle dough through a die. For modern extrusion, a twin-screw extruder was employed to obtain the noodles in a one-step process. The optimal range of moisture content used in the formulation was studied. Upon cooking, the noodles showed a decrease in cooking time and cooking loss with increasing moisture content in the formulation. All cooked noodles showed comparable tensile strength, but those extruded by a twin-screw extruder had substantially greater elongation. Scanning electron micrographs revealed that the noodles prepared using the extruder had a denser starch matrix, while those obtained from a capillary rheometer showed the aggregation of starch fragments relevant to the existence of starch gelatinization endotherm from differential scanning calorimetry. This indicated that the extrusion process using the twin-screw extruder provided a more uniform starch transformation, i.e., more starch granule disruption and gelatinization, thus giving the noodles a more coherent structure and better extensibility after cooking. The obtained results suggested that different thermomechanical processes used in the noodle industry gave the extruded rice noodles different qualities respective to their different microstructures.

scholarly journals Investigation of the Thermal and Hydrolytic Degradation of Polylactide during Autoclave Foaming

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2624
Author(s):  
Julia Dreier ◽  
Christian Brütting ◽  
Holger Ruckdäschel ◽  
Volker Altstädt ◽  
Christian Bonten
Keyword(s):  
Thermal Degradation ◽  
Hydrolytic Degradation ◽  
Reactive Extrusion ◽  
Foaming Properties ◽  
Twin Screw Extruder ◽  
Degradation Behavior ◽  
Screw Extruder ◽  
Melt Strength ◽  
Twin Screw ◽  
Good Potential

Polylactide (PLA) is one of the most important bioplastics worldwide and thus represents a good potential substitute for bead foams made of the fossil-based Polystyrene (PS). However, foaming of PLA comes with a few challenges. One disadvantage of commercially available PLA is its low melt strength and elongation properties, which play an important role in foaming. As a polyester, PLA is also very sensitive to thermal and hydrolytic degradation. Possibilities to overcome these disadvantages can be found in literature, but improving the properties for foaming of PLA as well as the degradation behavior during foaming have not been investigated yet. In this study, reactive extrusion on a twin-screw extruder is used to modify PLA in order to increase the melt strength and to protect it against thermal degradation and hydrolysis. PLA foams are produced in an already known process from the literature and the influence of the modifiers on the properties is estimated. The results show that it is possible to enhance the foaming properties of PLA and to protect it against hydrolysis at the same time.

Step-Scan DSC Study on the Melting Behavior of Polypropylene/Attapulgite Nanocomposites

2011 ◽  
Vol 284-286 ◽  
pp. 763-768
Author(s):  
Li Li Sun ◽  
Kun Hu ◽  
Lin Chen ◽  
Kang Zheng ◽  
Xing You Tian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Melting Behavior ◽  
Secondary Crystallization ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Multiple Melting ◽  
Scanning Electron

Attapulgite(AT) was modified by grafting with butyl acrylate(BA) via polymerizations initiated by Gamma radiation. The polypropylene(PP)/AT nanocomposites were synthesized via melting extrude in a twin-screw extruder. The thermogravimetry(TG) and scanning electron microscopy (SEM) were used to assess the graft ratio of the hybrid materials and the dispersion of AT, respectively. Step-scan differential scanning calorimetry(SSDSC) was used to study the influence of AT on the crystallization and subsequent melting behavior. The results indicated that PP and PP/AT nanocomposites underwent multiple melting and secondary crystallization processes during heating. The melting behaviours of PP and PP/AT nanocomposites varied with the variation of crystallization temperature and AT content.

Crystal Morphology and Thermal Properties of PA6/PP-g-MAH/POE Blends

2011 ◽  
Vol 366 ◽  
pp. 314-317
Author(s):  
Ming Tao Run ◽  
Wen Zhou ◽  
Bing Tao Xing ◽  
Meng Yao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Crystal Morphology ◽  
Crystallization Rate ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Acicular Crystal ◽  
Polarized Optical Microscopy ◽  
Twin Screw ◽  
Higher Temperature

The crystal morphology and thermal properties of the PA6/PP-g-MAH/POE blends prepared by twin-screw extruder were studied by polarized optical microscopy (POM) and differential scanning calorimetry (DSC) respectively. The results suggest that the crystal morphology of PA6 is acicular crystal while PP-g-MAH is micro-spherulites; The acicular crystals form across POE phase to PA6 phase, and the acicular crystals of PA6 in the POE phase have better regularity in dimension than those in amorphous PA6 phase. Acting as a compatibilizer, PP-g-MAH improves the miscibility of PA6 and POE, leading to the glass transition temperature of the blends decreases gradually with increasing POE contents. PA6 and PP-g-MAH can crystallize individually, and the formed PA6 crystals induced the crystallization of PP-g-MAH at higher temperature; furthermore, PP-g-MAH and POE components can increase the crystallization rate of PA6.

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