| 1. |
- Sanandaji, Nima, et al.
(författare)
-
Unusual crystals of poly(epsilon-caprolactone) by unusual crystallisation : The effects of rapid cooling and fast solvent loss on the morphology, crystal structure and melting
- 2013
-
Ingår i: Polymer. - : Elsevier BV. - 0032-3861 .- 1873-2291. ; 54:5, s. 1497-1503
-
Tidskriftsartikel (refereegranskat)abstract
- The lateral habit, unit cell structure and melting behaviour of single crystals of poly(epsilon-caprolactone) (PCL) prepared by the rapid expansion of a supercritical solution technique was studied by AFM at ambient and higher temperatures and by grazing-incident X-ray scattering using a synchrotron source. After dissolving PCL in a solution of supercritical CO2 and 0.1 vol.% chloroform, an extremely fast phase transfer from a supercritical to a gas-like state occurred during expansion into atmospheric conditions, leading to a temporary temperature drop to below -;50 degrees C at the silica surface where the crystals were deposited. Single crystals of a hitherto unreported rectangular lateral habit were observed. Six-sided crystals were also observed, but they were fewer than the rectangular crystals and in addition the angles between the lateral faces were different from the theoretical angles between adjacent {110} faces and {110} and {100} faces. X-ray scattering indicated a polymorphic structure also including the orthorhombic (110) and (200) diffraction peaks. Distinct low angle peaks essentially along the c-axis indicated a stacking on a very fine scale (3.7-4.7 nm) within the crystals. The equatorial diffraction peaks indicated a less dense packing of the PCL stems. Rectangular single crystals with a height according to AFM of 11-27 nm melted between 40 and 45 degrees C, which is lower than the melting points (55 degrees C) recorded for the distorted six-sided crystals. The unusual conditions for crystallisation used gave the polymer molecules a severe limitation to rearrange from the initial random coil state. The facetted crystals consisted of a stack of 4 nm thick blocks; these blocks most probably constituted a regular variation in molecular packing, i.e. molecular order. The pronounced changes in the angles between adjacent faces from those observed in mature PCL crystals and the wide-angle X-ray scattering data indicated the presence of conformational disorder in the crystals.
|
|
| 2. |
- Henrik Ullsten, N., et al.
(författare)
-
Extruded high quality materials from wheat gluten
- 2010
-
Ingår i: Polymers from Renewable Resources. - : SAGE Publications. - 2041-2479 .- 2045-1377. ; 1:4, s. 173-186
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, we report that the addition of ammonium hydroxide (NH4OH)significantly enhance the properties of extruded WG-based materials. The grainystructure disappeared and the extrudate became more uniform and glossy. Thebarrier properties improved and the oxygen permeability at dry conditions was aslow as that for a number of petroleum-based plastics (poly(ethylene terephthalateand polyamide 66). The protein structure in this material was extensivelyaggregated, which improved the strength and stiffness; there was a ca 4-foldincrease in maximum stress compared to that of the NH4OH-free samples. Theprotein solubility decreased to almost zero. Even a severe sonication treatmentin sodium dodecyl sulphate (SDS) did not increase the solubility. The only typeof protein that it was possible to extract was the 'thermo-resistant' w-gliadinslacking disulfide-bonds. Our result provides new opportunities to develop a WGbasedfilm extrudate for potential use as e.g. a renewable barrier layer in foodand non-food laminate packagings.
|
|
| 3. |
|
|
| 4. |
- Larsson, M, et al.
(författare)
-
When Life-Saving Is Life-Threatening
- 2014
-
Ingår i: SCIENCE TRANSLATIONAL MEDICINE. - 1946-6234. ; 6:222
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 5. |
- Akhlaghi, Shahin, et al.
(författare)
-
Deterioration of acrylonitrile butadiene rubber in rapeseed biodiesel
- 2015
-
Ingår i: Polymer degradation and stability. - : Elsevier BV. - 0141-3910 .- 1873-2321. ; 111, s. 211-222
-
Tidskriftsartikel (refereegranskat)abstract
- The deterioration of acrylonitrile butadiene rubber (NBR) exposed to rapeseed biodiesel at 90 degrees C was studied. The oxidation of biodiesel and NBR during ageing was monitored by H-1 NMR and infrared spectroscopy, HPLC and titration methods. The oxidation of biodiesel was impeded in the presence of NBR, but promoted in biodiesel-exposed rubber. This was explained as being due to the migration of stabilizer from the rubber to biodiesel, the diffusion of dissolved oxygen from biodiesel into NBR and the absorption of oxidation precursors of biodiesel by the rubber. The resemblance between the anomalous sorption kinetics of biodiesel in NBR and the equilibrium benzene uptake by the aged rubbers revealed that biodiesel caused a network defect in NBR, resulting in a gradual increase in the equilibrium swelling. The cleavage of crosslinks was implausible since the Young's modulus of the rubber at low strains, disregarding an initial decrease, increased with increasing exposure time. The appearance of 'naked' carbon black particles in the scanning electron micrographs of the aged rubbers and a drastic decrease in the strain-at-break of NBR after exposure to biodiesel suggests that internal cavitation was caused by the attack of biodiesel on the acrylonitrile units of NBR.
|
|
| 6. |
- Arabasadi, Z., et al.
(författare)
-
Prediction and optimization of fireproofing properties of intumescent flame retardant coatings using artificial intelligence techniques
- 2013
-
Ingår i: Fire safety journal. - : Elsevier BV. - 0379-7112 .- 1873-7226. ; 61, s. 193-199
-
Tidskriftsartikel (refereegranskat)abstract
- A multi-structured architecture of artificial intelligence techniques including artificial neural network (ANN), adaptive neuro-fuzzy-inference-system (ANFIS) and genetic algorithm (GA) were developed to predict and optimize the fireproofing properties of a model intumescent flame retardant coating including ammonium polyphosphate, pentaerythritol, melamine, thermoplastic acrylic resin and liquid hydrocarbon resin. By implementing ANN on heat insulation results of coating samples, prepared based on a L16 orthogonal array, mean fireproofing time (MFPT) values were properly predicted. The predicted data were then proved to be valid through performing closeness examinations on fuzzy inference systems results regarding their experimental counterparts. However, the possible deviations tapped into phenomena like foam detachment and char cracking were alleviated by ANFIS modeling embedded with pertinent fuzzy rules based on the sole and associative practical role of used additives. The contribution of each intumescent coating component on the formulation with optimized fireproofing behavior was then explored using GA modeling. A similar optimization procedure was also conducted using conventional Taguchi experimental design but the GA based optimized intumescent coating was found to exhibit higher MFPT value than that suggested by the Taguchi method.
|
|
| 7. |
|
|
| 8. |
- Bromark, M, et al.
(författare)
-
Wear of PVD Ti/TiN multilayer coatings
- 1997
-
Ingår i: SURFACE & COATINGS TECHNOLOGY. - : ELSEVIER SCIENCE SA LAUSANNE. - 0257-8972. ; 90:3, s. 217-223
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The wear characteristics of PVD Ti/TiN multilayer coatings subjected to two-body abrasion and particle erosion have been studied using diamond slurry and silicon carbide particles as abrasive medium and erodant, respectively. The abrasive wear rate of the
|
|
| 9. |
- Gahlin, R, et al.
(författare)
-
The crater grinder method as a means for coating wear evaluation - An update
- 1997
-
Ingår i: SURFACE & COATINGS TECHNOLOGY. - : ELSEVIER SCIENCE SA LAUSANNE. - 0257-8972. ; 90:1-2, s. 107-114
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The crater grinder test has been developed in order to obtain the abrasive resistance of thin coatings. It is capable of determining the specific abrasive wear rate of the coating and the substrate individually, even for very thin coatings. This paper rep
|
|
| 10. |
- Krook, M., et al.
(författare)
-
A study on montmorillonite/polyethylene nanocomposite extrusion-coated paperboard
- 2005
-
Ingår i: Packaging technology & science. - : Wiley. - 0894-3214 .- 1099-1522. ; 18:1, s. 11-20
-
Tidskriftsartikel (refereegranskat)abstract
- Extrusion coating was used to obtain montmorillonite/polyethylene-coated paperboard. The coating was prepared from a master batch containing maleated polyethylene, low-density polyethylene and 32 wt.% polyvinylpyrrolidone-surface-modified montmorillonite clay, which was blended with different amounts of low-density polyethylene to yield composites with 4 wt.% and 8.3 wt.% montmorillonite. X-ray diffraction revealed that the clay stacks in the coating were more extensively intercalated than in the original surface-modified clay. Transmission electron microscopy showed that the clay stacks were, to a large extent, separated by the high shear forces during extrusion into smaller evenly distributed entities. This was, unfortunately, achieved at the expense of the formation of a great many voids and pinholes, as revealed by transmission electron microscopy and dye staining. This had strong negative effects on the oxygen barrier properties but only a modest effect on the water vapour permeability. Tensile tests showed that the coating was always ductile and that the coating paperboard adhesion decreased with increasing clay content. The creasability was good and unaffected by the presence of the filler in the coating. Thermogravimetry showed that the degradation temperature in air of the filled coatings were of the order of 10degreesC higher than that of unfilled polyethylene.
|
|
