scholarly journals Vinyl Ester Resin Modified with Acrylated Epoxidised Soybean (AESO) and Linseed (AELO) Oils: Effect of Additional Urethane Crosslinking

2017 ◽  
Vol 25 (5) ◽  
pp. 363-370
Author(s):  
S. Grishchuk ◽  
J. Karger-Kocsis
Keyword(s):  
Thermal Analysis ◽  
Fracture Toughness ◽  
Thermal Degradation ◽  
Vinyl Ester ◽  
Crosslink Density ◽  
Room Temperature ◽  
Compact Tension ◽  
Vinyl Ester Resin ◽  
Strong Decrease ◽  
Scanning Calorimetry

Bisphenol A-based vinyl ester resin (VE) was modified with acrylated epoxidised soybean and linseed oils (AESO and AELO, respectively) in 10 wt.%. The double bond/epoxy ratio in these functionalised vegetable oils was practically the same, i.e. 30/70%, allowing us to deduce effects caused by the different unsaturations in the parent oils. The crosslink density of the resins was enhanced by adding polyisocyanate. The glass transition temperature (Tg) of the hybrids was determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). Resistance to thermal degradation was assessed by thermogravimetric analysis (TGA). The fracture toughness and energy (Kc and Gc, respectively) were determined on compact tension specimens at room temperature. Incorporation of AESO and AELO reduced the Tg of VE along with slight reductions in the Kc and Gc data. The Tg reduction was less for AELO than AESO which was attributed to the higher functionality of AELO compared to AESO. Urethane crosslinking of VE (VEUH) prominently enhanced the Tg. Modification of VEUH with AES(L)O enhanced the Tg due to additional crosslinks. Urethane hybridisation was associated with a strong decrease in both Kc and Gc compared to those of the parent VE. Kc and Gc of VEUH did not change practically as a function of blending with AES(L)O. Incorporation of AES(L)O reduced the resistance to thermal degradation of both VE and VEUH.

scholarly journals Studies on Viscoelastic, Thermal and Morphological Properties of Vinyl Ester – Mixed Diluents System

2017 ◽  
Vol 62 (3) ◽  
pp. 1845-1850
Author(s):  
Jagesh Kumar Ranjan ◽  
Raghu Raja Pandiyan Kuppusamy ◽  
Sudipta Goswami
Keyword(s):  
Thermal Analysis ◽  
Viscoelastic Properties ◽  
Vinyl Ester ◽  
Domain Size ◽  
Morphological Properties ◽  
Vinyl Ester Resin ◽  
Dynamic Mechanical Analyzer ◽  
Scanning Calorimetry ◽  
The Difference ◽  
Isothermal Mode

Abstract Vinyl ester resin networks formed by using mixture of diluents were prepared. Methyl methacrylate (MMA) diluent was mixed in various proportions with vinyl ester resin which was already premixed with styrene diluent (45 wt. %). Weight ratios e.g. 80:20, 70:30 and 60:40 of VE resin: MMA diluents were studied. Viscoelastic properties of the cross-linked resin were studied by dynamic mechanical analyzer in terms of storage modulus and tanδ. Thermal analysis was performed using non-isothermal mode of Differential scanning calorimetry. The samples with mixed diluents, showed higher modulus, and glass transition temperature in comparison to that of the pure vinyl ester-styrene resin cross-linked in presence of styrene only. The difference in thermal stability between vinyl ester-styrene and vinyl ester-MMA-styrene was checked. Vinyl Ester - 20 wt. % MMA-Styrene samples have the best thermal property among all other prepared samples. Multiphase morphology was formed for the thermoset crosslinked with mixed diluents in contrast to that formed with single diluent. With increase in MMA content in the resin dispersed domain size increased.

Cure and Dynamic-Mechanical Behaviors of Vinyl Ester Resinfilled with Multi-Walled Carbon Nanotubes

2010 ◽  
Vol 150-151 ◽  
pp. 1413-1416 ◽  
Author(s):  
Hong Yan Chen ◽  
Zhen Xing Kong ◽  
Ji Hui Wang
Keyword(s):  
Carbon Nanotubes ◽  
Vinyl Ester ◽  
Mechanical Response ◽  
Cure Kinetics ◽  
Crosslinking Density ◽  
Vinyl Ester Resin ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The cure kinetics of Derakane 411-350, a kind of vinyl ester resin, and its suspensions containing multi-walled carbon nanotubes( MWCNTs) were investigated via non-isothermal dynamic scanning calorimetry (DSC) measurements. The results showed that incorporation of MWCNTs into vinyl ester resin excessively reduces polymerization degree and crosslinking density of vinyl ester resin. For suppressing the negative effect caused by nanotubes, the higher temperature initiator combined with the initiator MEKP was used. Dynamic-mechanical Behavior testing was then carried out on the cured sample in order to relate the curing behavior of MWCNTs modified resin suspensions to mechanical response of their resulting nanocomposites. It was revealed that nanocomposites containing MWCNTs possessed larger storage modulus values as well as higher glass transition temperatures (Tg) as compared to those without MWCNTs after using mixed intiators system to improve the degree of cure.

scholarly journals A thermal degradation study of Y and La methanesulfonates

2006 ◽  
Vol 71 (8-9) ◽  
pp. 905-915
Author(s):  
Moura de ◽  
Jivaldo Matos ◽  
Farias de
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Differential Thermal Analysis ◽  
Thermal Degradation ◽  
Degradation Process ◽  
Oxide Formation ◽  
Scanning Calorimetry ◽  
Degradation Study ◽  
Thermogravimetric Data ◽  
Thermal Degradation Process

The synthesis, characterization and thermal degradation of yttrium and lanthanum methanesulfonates is reported. The prepared salts were characterized by elemental analysis and infrared spectroscopy. The thermal degradation study was performed using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC).Using the thermogravimetric data, a kinetic study of the dehydration ofY and Lamethanesulfonates was performed employing the Coats-Redfern and Zsak?methods. It was verified that under heating, yttrium and lanthanum methanesulfonates undergo three main processes: dehydration, thermal degradation and oxide formation. Furthermore, depending on the nature of the atmosphere, i.e., inert or oxidant, the thermal degradation process could be endothermic (N2) or exothermic (air).

NiTi Shape Memory Alloy Used for Multiple-Resetting Actuator for Fire Protection

2017 ◽  
Vol 907 ◽  
pp. 8-13 ◽  
Author(s):  
Lucian Burlacu ◽  
Nicanor Cimpoeşu ◽  
Nicoleta Monica Lohan ◽  
Leandru Gheorghe Bujoreanu
Keyword(s):  
Thermal Analysis ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Fire Protection ◽  
Room Temperature ◽  
Parent Phase ◽  
Niti Shape Memory Alloy ◽  
Scanning Calorimetry ◽  
Protection Systems ◽  
Executive Elements

The paper introduces the possibility to replace the “wet alloy”, used for sprinkler-triggering within automatic fire protection systems, with a shape memory alloy (SMA) type. The idea of the present application is based on the thermoelastic reversible martensitic transformation, governing SMA functioning, which has completely reversible character, and enables the occurrence of two-way shape memory effect (TWSME) after the application of a thermomechanical treatment called “training”. For this purpose a commercial NiTi rod, which was martensitic at room temperature, was subjected to thermal analysis tests, performed by differential scanning calorimetry (DSC) and dilatometry. Martensite (M) reversion to parent phase (A), during heating, was emphasized by an endothermic peak on the DSC thermogram and by a length shrinkage, on the dilatogram. The capacity to develop TWSME was revealed by the change in displacement-temperature variation, with increasing the number of training cycles. This stabilized fully reversible behavior recommends NiTi rods as executive elements of a new concept of resettable sprinkler for fire protection.

scholarly journals Thermal Degradation of Four Bamboo Species

BioResources ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 414-425 ◽  
Author(s):  
Parnia Zakikhani ◽  
Rizal Zahari ◽  
Mohamed Thariq Hameed Sultan ◽  
Dayang Laila Abang Abdul Majid
Keyword(s):  
Thermal Analysis ◽  
Thermal Degradation ◽  
Nitrogen Atmosphere ◽  
Bamboo Species ◽  
Scanning Calorimetry ◽  
Degradation Behaviour ◽  
Thermal Stabilities ◽  
Higher Temperature ◽  
Dendrocalamus Asper ◽  
Bottom To Top

Bamboo, among other natural plants, has a special structure, with different characterization along the culms and between species. In this study, the thermal stabilities of four bamboo species, named Dendrocalamus pendulus (DP), Dendrocalamus asper (DA), Gigantochloa levis (GL), and Gigantochloa scortechinii (GS), were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) under a nitrogen atmosphere. Each species was divided into three different portions: bottom, middle, and top, and fibres were manually extracted from the specified sections of each species. The thermal analysis of extracted bamboo fibres indicated that the thermal degradation behaviour of each bamboo species varied from bottom to top and between species. However, these variations were lower in DA species compared to GS, GL, and DP, because of minor differences between lignocellulosic components of its three portions. The top and middle portions of the four species degraded at a higher temperature range (314 to 379 °C) than the bottom portions. The results of this study suggest that DA and GS species, according to their thermal stabilities, are most suitable for use as reinforcement in composite materials.

Investigation of kinetic triplets for thermal degradation of thermally cured vinyl ester resin systems and lifetime predictions

2018 ◽  
Vol 133 (2) ◽  
pp. 881-891 ◽  
Author(s):  
Paramsamy Kannan Vimalathithan ◽  
Claudia Barile ◽  
Chinnaswamy Thangavel Vijayakumar
Keyword(s):  
Thermal Degradation ◽  
Vinyl Ester ◽  
Vinyl Ester Resin ◽  
Kinetic Triplets

Conductivity and Thermal Analysis Studies of Solid Polymeric Electrolytes Based on Plasticized Hydroxyethyl Cellulose

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Gilmara O. Machado ◽  
Robert E. Prud’homme ◽  
Agnieszka Pawlicka
Keyword(s):  
Thermal Analysis ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Lithium Perchlorate ◽  
Hydroxyethyl Cellulose ◽  
Conductivity Measurements ◽  
Scanning Calorimetry ◽  
Good Material ◽  
Polymeric Electrolytes ◽  
Perchlorate Salt

AbstractTransparent film samples of hydroxyethyl cellulose (HEC) based on solid polymeric electrolytes (SPE) were prepared by the plasticization of HEC with glycerol and addition of lithium perchlorate salt. SPEs with different quantities of glycerol and LiClO4 were studied by electrochemical impedance spectroscopy (EIS), Dynamic Mechanical Thermal Analysis (DMTA), TGA (Thermogravimetric Analysis) and DSC (Differential Scanning Calorimetry). The ionic conductivity measurements revealed that the sample containing [O]/[Li]=8 and 48% of glycerol showed the conductivity value of almost 10-4 S/cm at room temperature. The TGA analysis of electrolytes with high plastizant and salt concentrations showed 25% weight loss after heating to 130 °C, which can be related to the liberation of absorbed water. Finally, DMTA measurements showed changes attributed to the glass transition (Tg) evidenced by the decrease in the elastic modulus value and peaks in the tanδ curves. These results demonstrated that HEC is a good material to be used as a matrix for new solid polymeric electrolytes.

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