scholarly journals Analysis of Ageing Processes of Semi-Crystalline Materials

2020 ◽  
Vol 57 (3) ◽  
pp. 41-51
Author(s):  
Aleksandra Kalwik ◽  
Przemyslaw Postawa ◽  
Marcin Nabialek
Keyword(s):  
Differential Scanning Calorimetry ◽  
Test Chamber ◽  
Optical Microscope ◽  
Polymer Materials ◽  
Scanning Calorimetry ◽  
Crystalline Materials ◽  
Fluorescent Lamps ◽  
Uv Ageing ◽  
Ageing Processes ◽  
The Impact

The article presents the influence of accelerated UV ageing on the structural properties of selected polymer materials. In this study, 3 types of materials from a group of thermoplastics known as PP30T, PE, POM were used. The test samples were prepared by injection moulding. In turn, an accelerated UV ageing process (600 h) was carried out in the UV Test chamber with fluorescent lamps characterized by a wavelength of 313 nm. Changes in the structure of the tested materials were observed by using an optical microscope. Measurements of gloss on the surface of primary samples that were exposed to UV rays were also taken. In addition, the structure of primary and aged samples was tested by differential scanning calorimetry (DSC). The conducted studies have demonstrated the impact of UV radiation on the changes in the surface layer of tested materials.

scholarly journals STRUCTURAL AND MECHANICAL CHARACTERIZATION OF DEFORMED POLYMER USING CONFOCAL RAMAN MICROSCOPY AND DSC

2016 ◽  
Vol 3 ◽  
pp. 47-50
Author(s):  
Birgit Neitzel ◽  
Florian Aschermayer ◽  
Milan Kracalik ◽  
Sabine Hild
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Mechanical Characterization ◽  
Polymer Chains ◽  
Polymer Materials ◽  
Confocal Raman Microscopy ◽  
Micro Structure ◽  
Scanning Calorimetry ◽  
Confocal Raman

Polymers have various interesting properties, which depend largely on their inner structure. One way to influence the macroscopic behaviour is the deformation of the polymer chains, which effects the change in microstructure. For analyzing the microstructure of non-deformed and deformed polymer materials, Raman spectroscopy as well as differential scanning calorimetry (DSC) were used. In the present study we compare the results for crystallinity measurements of deformed polymers using both methods in order to characterize the differences in micro-structure due to deformation. The study is ongoing, and we present the results of the first tests.

scholarly journals Mesomorphism behaviour and photoluminescent properties of new asymmetrical 1,2-di(4-alkoxybenzylidene)hydrazines

2019 ◽  
Vol 43 (1-2) ◽  
pp. 67-77 ◽  
Author(s):  
Adil A Awad ◽  
Al-Ameen Bariz OmarAli ◽  
Ahmed Jasim M Al-Karawi ◽  
Zyad Hussein J Al-Qaisi ◽  
Samer Ghanim Majeed
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Liquid Crystalline ◽  
Polarized Light ◽  
Luminescent Properties ◽  
Scanning Calorimetry ◽  
Crystalline Materials ◽  
X Ray ◽  
Step Procedure ◽  
Liquid Crystalline Materials

{1-[4-( n-Alkoxy)]-2-(4’-decyloxy)benzylidene}hydrazines ( n-alkoxy = O(CH2) nH, n = 1–9, 12, 16 or 18), an asymmetrical series of 1,2-disubstituted hydrazines, were prepared in a simple two-step procedure as a part of our continuing work in evaluating hydrophobic azine compounds as photoluminescent liquid crystalline materials. The compounds were characterized spectroscopically and their liquid crystalline behaviour and luminescent properties were evaluated using polarized light optical microscopy, differential scanning calorimetry and X-ray powder diffraction techniques. The studies revealed that all of these compounds are liquid crystalline materials exhibiting photoluminescent properties in the crystalline and liquid crystal states.

scholarly journals Solid state and sub-cooled liquid vapour pressures of substituted dicarboxylic acids using Knudsen Effusion Mass Spectrometry (KEMS) and Differential Scanning Calorimetry

2010 ◽  
Vol 10 (10) ◽  
pp. 4879-4892 ◽  
Author(s):  
A. M. Booth ◽  
M. H. Barley ◽  
D. O. Topping ◽  
G. McFiggans ◽  
A. Garforth ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Solid State ◽  
Dicarboxylic Acids ◽  
Estimation Methods ◽  
Scanning Calorimetry ◽  
Knudsen Effusion ◽  
Oh Groups ◽  
Knudsen Effusion Mass Spectrometry ◽  
The Impact

Abstract. Solid state vapour pressures of a selection of atmospherically important substituted dicarboxylic acids have been measured using Knudsen Effusion Mass Spectrometry (KEMS) over a range of 20 K (298–318 K). Enthalpies of fusion and melting points obtained using Differential Scanning Calorimetry (DSC) were used to obtain sub-cooled liquid vapour pressures. They have been compared to estimation methods used on the E-AIM website. These methods are shown to poorly represent – OH groups in combination with COOH groups. Partitioning calculations have been performed to illustrate the impact of the different estimation methods on organic aerosol mass compared to the use of experimental data.

scholarly journals Solid state and sub-cooled liquid vapour pressures of substituted dicarboxylic acids using Knudsen Effusion Mass Spectrometry (KEMS) and Differential Scanning Calorimetry

2010 ◽  
Vol 10 (2) ◽  
pp. 5717-5749
Author(s):  
A. M. Booth ◽  
M. H. Barley ◽  
D. O. Topping ◽  
G. McFiggans ◽  
A. Garforth
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Solid State ◽  
Dicarboxylic Acids ◽  
Estimation Methods ◽  
Scanning Calorimetry ◽  
Knudsen Effusion ◽  
Oh Groups ◽  
Knudsen Effusion Mass Spectrometry ◽  
The Impact

Abstract. Solid state vapour pressures of a selection of substituted dicarboxylic acids have been measured using Knudsen Effusion Mass Spectrometry (KEMS). Enthalpies of fusion and melting points obtained using Differential Scanning Calorimetry (DSC) were used to obtain sub-cooled liquid vapour pressures. They have been compared to estimation methods used on the E-AIM website. These methods are shown to poorly represent -OH groups in combination with COOH groups. Partitioning calculations have been performed to illustrate the impact of the different estimation methods on organic aerosol mass compared to the use of experimental data.

scholarly journals The Influence of Lignin Diversity on the Structural and Thermal Properties of Polymeric Microspheres Derived from Lignin, Styrene, and/or Divinylbenzene

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2847 ◽  
Author(s):  
Marta Goliszek ◽  
Beata Podkościelna ◽  
Olena Sevastyanova ◽  
Barbara Gawdzik ◽  
Artur Chabros
Keyword(s):  
Thermal Properties ◽  
Structural Characteristics ◽  
Polymer Network ◽  
Eucalyptus Grandis ◽  
Nitrogen Adsorption ◽  
Optical Microscope ◽  
Scanning Calorimetry ◽  
Promising Alternative ◽  
Synthetic Materials ◽  
The Impact

This work investigates the impact of lignin origin and structural characteristics, such as molecular weight and functionality, on the properties of corresponding porous biopolymeric microspheres obtained through suspension-emulsion polymerization of lignin with styrene (St) and/or divinylbenzene (DVB). Two types of kraft lignin, which are softwood (Picea abies L.) and hardwood (Eucalyptus grandis), fractionated by common industrial solvents, and related methacrylates, were used in the synthesis. The presence of the appropriate functional groups in the lignins and in the corresponding microspheres were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR), while the thermal properties were studied by differential scanning calorimetry (DSC). The texture of the microspheres was characterized using low-temperature nitrogen adsorption. The swelling studies were performed in typical organic solvents and distilled water. The shapes of the microspheres were confirmed with an optical microscope. The introduction of lignin into a St and/or DVB polymeric system made it possible to obtain highly porous functionalized microspheres that increase their sorption potential. Lignin methacrylates created a polymer network with St and DVB, whereas the unmodified lignin acted mainly as an eco-friendly filler in the pores of St-DVB or DVB microspheres. The incorporation of biopolymer into the microspheres could be a promising alternative to a modification of synthetic materials and a better utilization of lignin.

scholarly journals Forensic Engineering of Advanced Polymeric Materials—Part VII: Degradation of Biopolymer Welded Joints

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1167
Author(s):  
W. Sikorska ◽  
M. Zięba ◽  
M. Musioł ◽  
M. Kowalczuk ◽  
H. Janeczek ◽  
...  
Keyword(s):  
Degradation Products ◽  
Bond Cleavage ◽  
Hydrolytic Degradation ◽  
Welding Process ◽  
Polymeric Materials ◽  
Polymer Materials ◽  
Scanning Calorimetry ◽  
Forensic Engineering ◽  
The Impact ◽  
Welding Processes

Welding technology may be considered as a promising processing method for the formation of packaging products from biopolymers. However, the welding processes used can change the properties of the polymer materials, especially in the region of the weld. In this contribution, the impact of the welding process on the structure and properties of biopolymer welds and their ability to undergo hydrolytic degradation will be discussed. Samples for the study were made from polylactide (PLA) and poly(3-hydroxyalkanoate) (PHA) biopolymers which were welded using two methods: ultrasonic and heated tool welding. Differential scanning calorimetry (DSC) analysis showed slight changes in the thermal properties of the samples resulting from the processing and welding method used. The results of hydrolytic degradation indicated that welds of selected biopolymers started to degrade faster than unwelded parts of the samples. The structure of degradation products at the molecular level was confirmed using mass spectrometry. It was found that hydrolysis of the PLA and PHA welds occurs via the random ester bond cleavage and leads to the formation of PLA and PHA oligomers terminated by hydroxyl and carboxyl end groups, similarly to as previously observed for unwelded PLA and PHA-based materials.

Effect of Intercritical Quenching on Microstructure and Mechanical Properties of Oil Casing Steel N80

2013 ◽  
Vol 395-396 ◽  
pp. 279-283
Author(s):  
Min Huang ◽  
Yu Wang ◽  
Ya Ni Zhang ◽  
Yue Wei Xie ◽  
Shuo Feng Li
Keyword(s):  
Tensile Strength ◽  
High Strength ◽  
Optical Microscope ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Scanning Calorimetry ◽  
Cross Sectional ◽  
Study Results ◽  
The Impact ◽  
The Sacrifice

In order to improve the toughness of oil casing steel N80 without the sacrifice of its original high strength, an intercritical quenching treatment was conducted under the temperature determined by a differential scanning calorimetry (DSC) analysis. Effects of intercritical quenching on the microstructure of oil casing steel N80 were characterized by means of optical microscope (OM) and scanning electron microscope (SEM). Tensile strength, reduction of cross-sectional area and microhardness were measured to evaluate the mechanical property of oil casing steel N80 after intercritical quenching treatment. The study results show that the tensile strength and microhardness of intercritical quenched oil casing steel N80 consisting of ferrite (F) and martensite (M) is slightly lower than that of tempered oil casing steel N80 composing of sorbite (S), yet which is still higher than that of full annealled oil casing steel N80 composing of pearlite (P) and a little amount of ferrite (F). In particular, the reduction of cross-sectional area of oil casing steel N80 intercritical quenched at 740°C is higher than those of tempered and full annealled. Additionally, both dimple and cleavage can be found on the impact fracture surface of N80 steel after intercritical quenching at 740°C. The toughness of oil casing steel N80 can be obviously improved by the intercritical quenching treatment at 740°C due to the formation of ferrite (F).

Crystal Polymorphs and Multiple Crystallization Pathways of Highly Pressurized 1-Ethyl-3-Methylimidazolium Nitrate

2019 ◽  
Vol 72 (2) ◽  
pp. 87 ◽  
Author(s):  
Hiroshi Abe ◽  
Takahiro Takekiyo ◽  
Yukihiro Yoshimura ◽  
Nozomu Hamaya ◽  
Shinichiro Ozawa
Keyword(s):  
Differential Scanning Calorimetry ◽  
High Pressure ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Low Temperature Crystallization ◽  
Temperature Crystallization

Crystal polymorphs and multiple crystallization pathways of a room-temperature ionic liquid (RTIL) were observed only under high pressure (HP). The RTIL was 1-ethyl-3-methylimidazolium nitrate, [C2mim][NO3]. The HP-crystal polymorphs were related to conformations of the C2mim+ cation, and the HP-crystal pathways determined by the presence or absence of the planar′ (P′) conformation of the C2mim+ cation were switched at the bifurcation pressure (PB). Above PB, modulated crystal structures derived from the HP-inherent P′ conformer. Simultaneous X-ray diffraction and differential scanning calorimetry measurements, accompanied by optical microscope observations, confirmed the normal low-temperature crystallization of [C2mim][NO3] under ambient pressure.

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