Cellulose fibers deconstruction by twin-screw extrusion with in situ enzymatic hydrolysis via bioextrusion

Composites of isotactic polypropylene (iPP) with different TiO2 nanoparticle loads (0.5 vol.%, 2 vol.% and 4 vol.%) were compounded by optimized twin screw extrusion. The crystallization behaviour of these semicrystalline nanocomposites was examined by differential scanning calorimetry (DSC), scanning electron microscope (SEM) and polarized optical light microscope (POM) combined with a hot stage module to pursue in-situ the structure development. Wet chemical etching was applied to highlight morphological details like spherulites and lamellar structures for SEM observations. An obvious influence of TiO2-nanoparticles on the crystallization could be verified.

Download Full-text

PLA/PA Bio-Blends: Induced Morphology by Extrusion

Polymers ◽

10.3390/polym12010010 ◽

2019 ◽

Vol 12 (1) ◽

pp. 10 ◽

Cited By ~ 1

Author(s):

Violeta García-Masabet ◽

Orlando Santana Pérez ◽

Jonathan Cailloux ◽

Tobias Abt ◽

Miguel Sánchez-Soto ◽

...

Keyword(s):

Mechanical Performance ◽

Reactive Extrusion ◽

Processing Parameters ◽

Poly Lactic Acid ◽

Twin Screw Extrusion ◽

Extrusion Die ◽

Screw Extrusion ◽

Twin Screw ◽

Speed Rotation

The effect of processing conditions on the final morphology of Poly(Lactic Acid) (PLA) with bio-based Polyamide 10.10 (PA) 70/30 blends is analyzed in this paper. Two types of PLA were used: Commercial (neat PLA) and a rheologically modified PLA (PLAREx), with higher melt elasticity produced by reactive extrusion. To evaluate the ability of in situ micro-fibrillation (μf) of PA phase during blend compounding by twin-screw extrusion, two processing parameters were varied: (i) Screw speed rotation (rpm); and (ii) take-up velocity, to induce a hot stretching with different Draw Ratios (DR). The potential ability of PA-μf in both bio-blends was evaluated by the viscosity (p) and elasticity (k’) ratios determined from the rheological tests of pristine polymers. When PLAREx was used, the requirements for PA-μf was fulfilled in the shear rate range observed at the extrusion die. Scanning electron microscopy (SEM) observations revealed that, unlike neat PLA, PLAREx promoted PA-μf without hot stretching and the aspect ratio increased as DR increased. For neat PLA-based blends, PA-μf was promoted during the hot stretching stage. DMTA analysis revealed that the use of PLAREx PLAREx resulted in a better mechanical performance in the rubbery region (T > Tg PLA-phase) due to the PA-μf morphology obtained.

Download Full-text

Correction to: One-step twin-screw extrusion process of cellulose fibers and hydroxyethyl cellulose to produce fibrillated cellulose biocomposite

Cellulose ◽

10.1007/s10570-020-03569-w ◽

2020 ◽

Author(s):

Hesam Taheri ◽

Maiju Hietala ◽

Kristiina Oksman

Keyword(s):

Cellulose Fibers ◽

Extrusion Process ◽

Hydroxyethyl Cellulose ◽

Original Publication ◽

Twin Screw Extrusion ◽

Screw Extrusion ◽

Twin Screw ◽

One Step

In the original publication, the affiliation of all the authors were processed incorrectly. It has been updated in this correction.

Download Full-text

One-step twin-screw extrusion process of cellulose fibers and hydroxyethyl cellulose to produce fibrillated cellulose biocomposite

Cellulose ◽

10.1007/s10570-020-03287-3 ◽

2020 ◽

Vol 27 (14) ◽

pp. 8105-8119 ◽

Cited By ~ 1

Author(s):

Hesam Taheri ◽

Maiju Hietala ◽

Kristiina Oksman

Keyword(s):

Cellulose Fiber ◽

Cellulose Fibers ◽

Fiber Content ◽

Size Reduction ◽

Hydroxyethyl Cellulose ◽

Twin Screw Extrusion ◽

Screw Extrusion ◽

Twin Screw ◽

One Step ◽

Width Reduction

Abstract In this work, the defibrillation of cellulose fibers (CF) in the presence of hydroxyethyl cellulose (HEC) within the one-step twin-screw extrusion (TSE) process was examined. The effect of the TSE on cellulose fiber size reduction as well as CF-HEC biocomposites properties were investigated. The results showed that the TSE of cellulose fiber-hydroxyethyl cellulose (CF-HEC) with different cellulose fiber contents (50, 65, and 80 wt%) resulted in partial defibrillation of the cellulose fibers. The fractionation test of the cellulose fibers confirmed that their size was reduced and some fibrillation was observed in microscopy studies. The maximum width reduction of 46% occurred with 80 wt% cellulose content. However, the partial width reduction was also observed with 50% and 65 wt% of cellulose contents. Based on rheological measurements, the shear-viscosity trend of CF-HEC dispersion abruptly dropped when higher fiber content (80 wt%) was extruded, which was related to the fibrillation of the cellulose fibers as well as the reduction of the length. The extruded CF-HEC materials (powder form) were compression molded to prepare the biocomposites with different cellulose fiber contents (50, 65, and 80 wt%). The extruded CF-HEC powders were diluted with addition extra HEC to make biocomposites with lower fiber content (20%, 30%, and 40 wt%) and compression molded to study how the size reduction of the cellulose fibers affected the mechanical properties of biocomposites. The results showed that the E-modulus improved from 0.4 GPa of the neat HEC to 1.6 GPa for the composite with 40 wt% CF. Interestingly, the tensile strength of CF-HEC biocomposite with 40 wt% confirmed a clear improvement from 9.8 to 26.6 MPa, confirming good interaction between HEC and CF. Graphic abstract Preparation (mixing, TSE, and hot-pressing) and characterization (FE-SEM, rheometry, and tensile test) of CF-HEC biocomposite

Download Full-text

Fibrous soy protein meat analog from low moisture twin-screw extrusion

10.32469/10355/6035 ◽

2007 ◽

Author(s):

Suxuan Xu

Keyword(s):

Soy Protein ◽

Twin Screw Extrusion ◽

Screw Extrusion ◽

Twin Screw ◽

Meat Analog

Download Full-text

Enhanced Dispersive Mixing in Twin-Screw Extrusion via Extension-Dominated Static Mixing Elements of Varying Contraction Ratios

International Polymer Processing ◽

10.3139/217.3857 ◽

2020 ◽

Vol 35 (1) ◽

pp. 37-49 ◽

Cited By ~ 7

Author(s):

H. Chen ◽

V. Pandey ◽

S. Carson ◽

J. M. Maia

Keyword(s):

Twin Screw Extrusion ◽

Screw Extrusion ◽

Twin Screw ◽

Dispersive Mixing

Download Full-text

In-Line Rheo-Optical Investigation of the Dispersion of Organoclay in a Polymer Matrix during Twin-Screw Compounding

Polymers ◽

10.3390/polym13132128 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2128

Author(s):

Paulo F. Teixeira ◽

José A. Covas ◽

Loïc Hilliou

Keyword(s):

Local Heating ◽

Polymer Nanocomposite ◽

Structural Rearrangement ◽

Particle Dispersion ◽

Optical Investigation ◽

Twin Screw Extrusion ◽

Clay Particles ◽

Clay Dispersion ◽

Screw Extrusion ◽

Twin Screw

The dispersion mechanisms in a clay-based polymer nanocomposite (CPNC) during twin-screw extrusion are studied by in-situ rheo-optical techniques, which relate the CPNC morphology with its viscosity. This methodology avoids the problems associated with post extrusion structural rearrangement. The polydimethylsiloxane (PDMS) matrix, which can be processed at ambient and low temperatures, is used to bypass any issues associated with thermal degradation. Local heating in the first part of the extruder allows testing of the usefulness of low matrix viscosity to enhance polymer intercalation before applying larger stresses for clay dispersion. The comparison of clay particle sizes measured in line with models for the kinetics of particle dispersion indicates that larger screw speeds promote the break-up of clay particles, whereas smaller screw speeds favor the erosion of the clay tactoids. Thus, different levels of clay dispersion are generated, which do not simply relate to a progressively better PDMS intercalation and higher clay exfoliation as screw speed is increased. Reducing the PDMS viscosity in the first mixing zone of the screw facilitates dispersion at lower screw speeds, but a complex interplay between stresses and residence times at larger screw speeds is observed. More importantly, the results underline that the use of larger stresses is inefficient per se in dispersing clay if sufficient time is not given for PDMS to intercalate the clay galleries and thus facilitate tactoid disruption or erosion.

Download Full-text