Solid-State Synthesis of Water-Soluble Chitosan-g-Hydroxyethyl Cellulose Copolymers

Graft copolymers of chitosan with cellulose ether have been obtained by the solid-state reactive mixing of chitin, sodium hydroxide and hydroxyethyl cellulose under shear deformation in a pilot twin-screw extruder. The structure and composition of the products were determined by elemental analysis and IR spectroscopy. The physicochemical properties of aqueous solutions of copolymers were studied as a function of the composition, and were correlated to the mechanical characteristics of the resulting films to assess the performance of new copolymers as coating materials, non-woven fibrous materials or emulsifiers for interface stabilization during the microparticle fabrication process.

Download Full-text

Development of Thermoplastic Elastomers by Blending of Nitrile Rubbers with Nylon 6 in an Internal Mixer and by Reactive Mixing in a Twin Screw Extruder

Journal of Bionanoscience ◽

10.1166/jbns.2016.1386 ◽

2016 ◽

Vol 10 (5) ◽

pp. 403-413 ◽

Cited By ~ 2

Author(s):

DipakK. Setua

Keyword(s):

Nylon 6 ◽

Thermoplastic Elastomers ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Twin Screw ◽

Nitrile Rubbers ◽

Reactive Mixing ◽

Internal Mixer

Download Full-text

Unique Microstructure and Mechanical Properties from Melt Processing Poly(Lactide-co-Glycolide)/Poly(Trimethylene Carbonate)

MRS Proceedings ◽

10.1557/proc-1239-vv01-10 ◽

2009 ◽

Vol 1239 ◽

Author(s):

Jianbin Zhang ◽

Lian Luo ◽

Suping Lyu ◽

Bryant Pudil ◽

Jim Schley ◽

...

Keyword(s):

Mechanical Properties ◽

Extrusion Direction ◽

Melt Processing ◽

Water Soluble ◽

Twin Screw Extruder ◽

Trimethylene Carbonate ◽

Reactive Blending ◽

Screw Extruder ◽

Twin Screw

AbstractPoly(lactide) (PLA) and its copolymers degrade through hydrolysis into non-toxic and water soluble metabolic products in vivo. They are ideal materials for resorbable biomedical applications such as drug delivery and tissue engineering. However, these polymers are brittle and often need to be toughened. One of the most effective toughening methods is reactive blending, in which additives are dispersed into polymer matrices as small particles with strong bonding between the two materials. In this paper, we studied toughening poly(lactide-co-glycolide) (PLGA) through reactive blending with poly(trimethylene carbonate) (PTMC). We observed warm-like micelle or swollen warm-like micelle structures created during the reactive blending process with a twin screw extruder at high temperature. The micelle structures were orientated along the extrusion direction with their length ranging from 50 to 1000 nm and diameters about 50 nm. This structure could be produced only with a twin screw extruder. When a batch mixer was used, the PTMC additive (10 to 30 wt%) formed spheres with diameters on the order of 100-500 nm. The PLGA/PTMC copolymers formed in situ were responsible to this microstructure. The mechanical properties of this blend were significantly improved over the pure PLGA.

Download Full-text

In-line solid state prediction during pharmaceutical hot-melt extrusion in a 12mm twin screw extruder using Raman spectroscopy

European Journal of Pharmaceutics and Biopharmaceutics ◽

10.1016/j.ejpb.2014.03.002 ◽

2014 ◽

Vol 87 (3) ◽

pp. 606-615 ◽

Cited By ~ 16

Author(s):

Lien Saerens ◽

Dima Ghanam ◽

Cedric Raemdonck ◽

Kjell Francois ◽

Jürgen Manz ◽

...

Keyword(s):

Raman Spectroscopy ◽

Solid State ◽

Hot Melt Extrusion ◽

Twin Screw Extruder ◽

Melt Extrusion ◽

Screw Extruder ◽

State Prediction ◽

Twin Screw ◽

Hot Melt

Download Full-text

Influence of the Solidification Process on the Mechanical Properties of Solid-State Drawn PCL/Sepiolite Nanocomposite Tapes

Fibers ◽

10.3390/fib8110070 ◽

2020 ◽

Vol 8 (11) ◽

pp. 70

Author(s):

Maria Eriksson ◽

Han Goossens ◽

Ton Peijs

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Solid State ◽

Solidification Process ◽

Nanocomposite Films ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Extruded Films ◽

Twin Screw ◽

Subsequent Step

In this research, poly(ε-caprolactone) (PCL) was melt-mixed with sepiolite nanoclays in a twin-screw extruder. In a subsequent step, the extruded films were drawn in the solid state to highly oriented nanocomposite films or tapes. A twin-screw extruder equipped with a Sultzer mixer for improved mixing in combination with a bench top drawing unit was used to prepare oriented nanocomposite tapes of different sepiolite loading and draw ratios. In order to study the influence of the solidification step on the drawability of the materials, different cooling procedures were applied prior to drawing. Optical microscopy images showed that slow or fast solidification using different chill rolls settings (open or closed) for the cast films resulted in different morphological conditions for subsequent drawing. The addition of sepiolite nanofillers led to nucleation and faster crystallization kinetics and oriented tapes which deformed by homogenous deformation rather than necking. The addition of sepiolite significantly improved the mechanical properties of both undrawn and drawn PCL tapes and Young’s modulus (1.5 GPa) and tensile strength (360 MPa) for composites based on 4 wt% sepiolite were among the highest ever reported for PCL nanocomposites. Interestingly, samples cooled with open chill rolls (slow crystallization) showed the highest modulus while solidification with closed rolls (fast crystallization) showed the highest tensile strength after drawing.

Download Full-text

Translating solid state organic synthesis from a mixer mill to a continuous twin screw extruder

Green Chemistry ◽

10.1039/c8gc02036a ◽

2018 ◽

Vol 20 (19) ◽

pp. 4443-4447 ◽

Cited By ~ 21

Author(s):

Qun Cao ◽

Joseph L. Howard ◽

Deborah E. Crawford ◽

Stuart L. James ◽

Duncan L. Browne

Keyword(s):

Solid State ◽

Organic Synthesis ◽

Twin Screw Extruder ◽

Screw Extruder ◽

Twin Screw

A study on the translation of a solid-state fluorination reaction from a mechanochemical mixer-mill to a continuous twin-screw extruder is discussed herein.

Download Full-text

Determination of the phase structure of polymerblends by electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109604 ◽

1978 ◽

Vol 36 (1) ◽

pp. 492-493

Author(s):

Dr. G. Kaemof

Keyword(s):

Screw Extruder ◽

Electron Microscopic ◽

Thin Sections ◽

Single Screw Extruder ◽

Transmission Electron ◽

The Matrix ◽

Twin Screw ◽

Special Case ◽

Microscopic Investigations

A mixture of polycarbonate (PC) and styrene-acrylonitrile-copolymer (SAN) represents a very good example for the efficiency of electron microscopic investigations concerning the determination of optimum production procedures for high grade product properties.The following parameters have been varied:components of charge (PC : SAN 50 : 50, 60 : 40, 70 : 30), kind of compounding machine (single screw extruder, twin screw extruder, discontinuous kneader), mass-temperature (lowest and highest possible temperature).The transmission electron microscopic investigations (TEM) were carried out on ultra thin sections, the PC-phase of which was selectively etched by triethylamine.The phase transition (matrix to disperse phase) does not occur - as might be expected - at a PC to SAN ratio of 50 : 50, but at a ratio of 65 : 35. Our results show that the matrix is preferably formed by the components with the lower melting viscosity (in this special case SAN), even at concentrations of less than 50 %.

Download Full-text