Graft Polymerization of L-Lactide onto Cellulose in Ionic Liquid via Twin Screw Extruder

2013 ◽  
Vol 658 ◽  
pp. 8-12
Author(s):  
Xuan Zhong ◽  
Xian Tao Tong ◽  
Mu Huo Yu ◽  
Hai Feng Li ◽  
Huan Li ◽  
...  

A twin-screw extruder was used to carry out the ring opening graft polymerization of L-lactide onto cellulose through reactive extrusion process. Ionic liquid (1-butyl-3-methylimidazolium chloride) [Bmim]Cl and Sn(oct)2 were used as solvent and catalyst, respectively. FTIR, TGA and XRD were used to investigate the structure, thermal stability and crystalline behavior of the reaction products. The result showed a successful ring opening polymerization of L-lactide on cellulose. Furthermore, it showed a increased crystalline degree and thermal stability after being introduced the PLLA.

2012 ◽  
Vol 268-270 ◽  
pp. 605-609 ◽  
Author(s):  
Magdi E. Gibril ◽  
Hai Feng Li ◽  
Xin Da Li ◽  
Huan Li ◽  
Xuan Zhong ◽  
...  

Twin-screw extruder was used as a dissolution unit for microcrystalline cellulose with ionic liquid. Ionic liquid (1-butyl-3-methylimidazolium chloride) was applied as solvent and plasticizer; it was mixed with cellulose to prepare the extrusion mixture. The extrusion mixture was feed into twin screw extruder which was run under conditions; speed 65 rpm and 1400C. In order to determine whether the cellulose I has been transformed into cellulose II, the solubility, structure, crystallinty and thermal stability of the extrude cellulose were investigated by polarizing Optical microscope, FTIR, XRD and TGA, respectively. The results which were obtained from polarizing optical microscope showed a clear cellulose solution without undissolved cellulose. FTIR confirmed the transfer cellulose I into cellulose II. XRD result showed a decrease in degree of crystallinity and confirmed the change of cellulose I into cellulose II. Finally, TGA analysis approved that the thermal stability was decreased according to the decrease in crystallinity.


2021 ◽  
pp. 108201322110692
Author(s):  
Nispa Seetapan ◽  
Bootsrapa Leelawat ◽  
Nattawut Limparyoon ◽  
Rattana Yooberg

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.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2624
Author(s):  
Julia Dreier ◽  
Christian Brütting ◽  
Holger Ruckdäschel ◽  
Volker Altstädt ◽  
Christian Bonten

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.


Polymer ◽  
2000 ◽  
Vol 41 (9) ◽  
pp. 3395-3403 ◽  
Author(s):  
S. Jacobsen ◽  
H.G. Fritz ◽  
Ph. Degée ◽  
Ph. Dubois ◽  
R. Jérôme

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