scholarly journals Thepeculiaritiesofformation of cross-linked poly(2-ethyl-2-oxazoline) filmsand nanocompositeson theirbase

2020 ◽  
Vol 3 (2) ◽  
pp. 180-186
Author(s):  
O. M. Shevchuk ◽  
◽  
N. M. Bukartyk ◽  
M. R. Chobit ◽  
Z. Ya. Nadashkevych ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperatures ◽  
Nanocomposite Films ◽  
Cross Linking ◽  
Curing Process ◽  
Influence Of Temperature ◽  
Gel Fraction ◽  
Extremal Character

Cross-linked polymeric and nanocomposite films based on poly(2-ethyl-2-oxazoline) and modified mineral nanoparticles of hydroxyapatite and silica have been obtained via radical cross- linking initiated by peroxide containing reactive copolymers. The influence of temperature and additional cross-linking agents on the peculiarities of curing process has been studied. The obtained results reveal that at high temperatures the dependence of film gel-fraction values on time has the extremal character. Obtained cross-linked nanocomposite films are characterized by improved physico-mechanical properties that depend on the nature of mineral nanoparticles, content of peroxide containing copolymer and on the presence of additional cross-linking agent.

scholarly journals Structural and Thermo-Mechanical Properties of Poly(ε-caprolactone) Modified by Various Peroxide Initiators

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1101 ◽  
Author(s):  
Przybysz ◽  
Hejna ◽  
Haponiuk ◽  
Formela
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Dicumyl Peroxide ◽  
Organic Peroxides ◽  
Reactive Processing ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Gel Fraction

The modification of poly(ε-caprolactone) (PCL) was successfully conducted during reactive processing in the presence of dicumyl peroxide (DCP) or di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB). The peroxide initiators were applied in the various amounts of 0.5 or 1.0 pbw (part by weight) into the PCL matrix. The effects of the initiator type and its concentration on the structure and mechanical and thermal properties of PCL were investigated. To achieve a detailed and proper explication of this phenomenon, the decomposition and melting temperatures of DCP and BIB initiators were measured by differential scanning calorimetry. The conjecture of the branching or cross-linking of PCL structure via used peroxides was studied by gel fraction content measurement. Modification in the presence of BIB in PCL was found to effectively increase gel fraction. The result showed that the cross-linking of PCL started at a low content of BIB, while PCL modified by high DCP content was only partially cross-linked or branched. PCL branching and cross-linking were found to have a significant impact on the mechanical properties of PCL. However, the effect of used initiators on poly(ε-caprolactone) properties strongly depended on their structure and content. The obtained results indicated that, for the modification towards cross-linking/branching of PCL structure by using organic peroxides, the best mechanical properties were achieved for PCL modified by 0.5 pbw BIB or 1.0 pbw DCP, while the PCL modified by 1.0 pbw BIB possessed poor mechanical properties, as it was related to over cross-linking.

Study on Thermal and Mechanical Properties of Polyurethane Systems for In-Mould Decoration Ink

2014 ◽  
Vol 881-883 ◽  
pp. 850-853
Author(s):  
Jing Lin ◽  
Cheng Zheng ◽  
Shu Xuan Qian ◽  
Xian Fang Cai ◽  
Yong Shun Lan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Sorption ◽  
Phenolic Resin ◽  
Cross Linking ◽  
Thermal And Mechanical Properties ◽  
Elongation At Break ◽  
Swell Ratio ◽  
System A ◽  
Gel Fraction ◽  
The Cross

In this study, three polyurethane systems A (A450/RD181/L75), B(A450/RD181/N3390) and C(A450/RD181/2104/N3390) for in-mould decoration ink were studied. The results of thermogravimetric analysis showed that introducing rosin modified phenolic resin 2104 (RMPR) and N3390 into PU system A can improve the thermal stability, Moreover, Measurements of gel fraction and swell ratio showed that incorporation of N3390 is benificial for increasing the cross-linking density of PU systems as compared to L75 so as to increase the gel fraction and decrease the swell ratio.The tensile strength of cured PU systems increased following in the order: A<B<C, elongation at break is just the opposite. In addition, it is indicated that incorporation of N3390 is benificial for increasing the cross-linking density of PUs so as to improve the the shore A hardness and decease the water sorption.

scholarly journals The Effect of Curing Temperature on Cellulose Nanocrystal Reinforced Natural Rubber Latex

2020 ◽  
Vol 6 (1) ◽  
pp. 20-25
Author(s):  
N. A. H. Jailudin ◽  
Khairatun Najwa Mohd Amin
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Functional Group ◽  
Natural Rubber Latex ◽  
Curing Temperature ◽  
Cellulose Nanocrystal ◽  
Nanocomposite Films ◽  
Cross Linking ◽  
Rubber Latex ◽  
Transmission Electron

Cellulose nanocrystal (CNC) was extracted from filter paper and isolated via sulphuric acid hydrolysis. This CNC was used as reinforcing elements in natural rubber latex (NRL) along with the cross-linking agents to prepare nanocomposite films. The effect of CNC loading on the mechanical properties, functional group presence and the glass transition temperature (Tg) of CNC/NRL nanocomposite at curing temperature of 70°C and 80°C were studied, respectively. CNC size and dimension was characterized using transmission electron microscope (TEM). Significant improvement of Young’s modulus was observed as a result of the addition of CNC loading at 3 wt.% and the Tg only showed a small increase upon the addition of CNC. The best nanocomposite was found at a curing temperature of 80°C with a tensile strength of 144% improvement.

CF8C-PLUS

Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Properties ◽  
High Temperatures

Abstract CF8C-Plus is an austenitic casting grade similar to CF8C, but with improved chemistry to stay fully austenitic at high temperatures and thus retain good mechanical properties. This datasheet provides information on composition, microstructureand tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on casting and joining. Filing Code: SS-1006. Producer or source: Caterpillar Technical Center.

Electro-mechanical properties of multilayered aluminum nitride and platinum thin films at high temperatures

2019 ◽  
Vol 293 ◽  
pp. 128-135 ◽  
Author(s):  
P. Schmid ◽  
F. Triendl ◽  
C. Zarfl ◽  
S. Schwarz ◽  
W. Artner ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Aluminum Nitride ◽  
High Temperatures

scholarly journals Influence of Rhamnolipids and Ionic Cross-Linking Conditions on the Mechanical Properties of Alginate Hydrogels as a Model Bacterial Biofilm

2021 ◽  
Vol 22 (13) ◽  
pp. 6840
Author(s):  
Natalia Czaplicka ◽  
Szymon Mania ◽  
Donata Konopacka-Łyskawa
Keyword(s):  
Mechanical Properties ◽  
Pure Water ◽  
Testing Machine ◽  
Bacterial Biofilm ◽  
Ion Trapping ◽  
Cross Linking ◽  
Box Behnken Design ◽  
Compression Load ◽  
Alginate Hydrogels ◽  
Biofilm Structure

The literature indicates the existence of a relationship between rhamnolipids and bacterial biofilm, as well as the ability of selected bacteria to produce rhamnolipids and alginate. However, the influence of biosurfactant molecules on the mechanical properties of biofilms are still not fully understood. The aim of this research is to determine the effect of rhamnolipids concentration, CaCl2 concentration, and ionic cross-linking time on the mechanical properties of alginate hydrogels using a Box–Behnken design. The mechanical properties of cross-linked alginate hydrogels were characterized using a universal testing machine. It was assumed that the addition of rhamnolipids mainly affects the compression load, and the value of this parameter is lower for hydrogels produced with biosurfactant concentration below CMC than for hydrogels obtained in pure water. In contrast, the addition of rhamnolipids in an amount exceeding CMC causes an increase in compression load. In bacterial biofilms, the presence of rhamnolipid molecules does not exceed the CMC value, which may confirm the influence of this biosurfactant on the formation of the biofilm structure. Moreover, rhamnolipids interact with the hydrophobic part of the alginate copolymer chains, and then the hydrophilic groups of adsorbed biosurfactant molecules create additional calcium ion trapping sites.

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