Cure behavior of ethylene propylene diene terpolymer insulation for large composite rocket motor casing

2021 ◽  
Author(s):  
Isaac Kingstone Lesley Jabez ◽  
Urmila Das ◽  
Ramalingam Manivannan ◽  
Sarat Babu Anne
Keyword(s):  
Rocket Motor ◽  
Ethylene Propylene ◽  
Cure Behavior ◽  
Ethylene Propylene Diene Terpolymer

scholarly journals The effect of polyhedral oligomeric silsesquioxanes (POSSs) incorporation in ethylene-propylene-diene-terpolymer (EPDM): a thermal study

2021 ◽  
Author(s):  
Ignazio Blanco ◽  
Traian Zaharescu
Keyword(s):  
Room Temperature ◽  
Thermal Characterization ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Dsc Analysis ◽  
Γ Irradiation ◽  
Scanning Calorimetry ◽  
Ethylene Propylene ◽  
Oligomeric Silsesquioxane ◽  
Ethylene Propylene Diene Terpolymer ◽  
Dynamic Heating

AbstractA series of ethylene-propylene-diene-terpolymer (EPDM)/polyhedral oligomeric silsesquioxane (POSS) composites at different percentage of POSS were prepared and subjected to γ-irradiation. Both irradiated and non-irradiated EPDM and composites were investigated by the means of thermal analysis to verify if the presence of POSS molecules is able to reduce the oxidation level of free radicals generated during the degradation and to evaluate the effects of the irradiation. EPDM composites at 1, 3 and 5 mass% of POSS were thus degraded in a thermogravimetric (TG) balance in dynamic heating conditions (25–700 °C), in both inert and oxidative atmosphere by flowing nitrogen and air respectively. Thermal characterization was then completed by carrying out Differential Scanning Calorimetry (DSC) analysis from sub-ambient to better highlight the melting of the polymer and polymer composites occurring just above the room temperature. FTIR spectroscopy was also performed for the prepared samples to check the presence of the molecular filler in the composites and for the TG’s residue at 700 °C, in order to evaluate its nature. DSC and TGA parameters were detected and discussed to have information about the effect of the degradation’s environment, the effect of irradiation on polymer stabilization and the effect of POSS content in the polymer matrix.

FOAMING AND MOISTURE CROSSLINKING OF VINYL TRIETHOXY SILANE GRAFTED ETHYLENE–PROPYLENE–DIENE TERPOLYMER

2022 ◽  
Author(s):  
Zhengwei Lin ◽  
Qinghong Zhang ◽  
Gongliang Wang ◽  
Jie Mao ◽  
Martin Hoch ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Side Reaction ◽  
High Energy ◽  
Expansion Ratio ◽  
Ethylene Propylene ◽  
Foaming Process ◽  
The Matrix ◽  
High Energy Absorption ◽  
Ethylene Propylene Diene Terpolymer

ABSTRACT Moisture crosslinking of polyolefins has attracted increasing attention because of its high efficiency, low cost, and easy processing. However, the crucial shortcoming of moisture crosslinking is that the side reaction of peroxide scorch (precrosslinking) simultaneously occurs in silane grafting. It has been recognized that making peroxide precrosslinking useful is an effective way to broaden the application of moisture crosslinking. A novel foaming process combined with moisture crosslinking is proposed. The matrix of ethylene–propylene–diene terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide as initiator. Foaming was then carried out with azodicarbonamide (AC) as the blowing agent by making use of precrosslinking. Subsequently, the EPDM-g-VTES foams were immersed in a water bath to achieve moisture crosslinking with dibutyl tin dilaurate as the catalyst. The results showed that VTES was grafted onto EPDM and the EPDM-g-VTES foams were successfully crosslinked by moisture. The EPDM-g-VTES compounds with AC obtained great cells by compression molding with the help of precrosslinking. The mechanical property of the EPDM-g-VTES foam was improved by moisture crosslinking. The moisture-cured foam with 4 wt% AC had an expansion ratio of about three times, which could bear large deformation and showed a high energy-absorption effect.

scholarly journals Aging Mechanisms and Monitoring of Cable Polymers

2020 ◽  
Vol 6 (3) ◽  
Author(s):  
Nicola Bowler ◽  
Shuaishuai Liu
Keyword(s):  
Nuclear Power ◽  
Low Voltage ◽  
Capacitive Sensor ◽  
Dissipation Factor ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Aging Mechanisms ◽  
Nondestructive Measurements ◽  
Ethylene Propylene Diene Terpolymer

Aging mechanisms of two polymeric insulation materials that are used widely in nuclear power plant low-voltage cables; cross-linked polyethylene (XLPE) and ethylene propylene rubber/ethylene propylene diene terpolymer (EPR/EPDM), are reviewed. A summary of various nondestructive methods suitable for evaluation of cable insulation is given. A capacitive sensor capable of making local nondestructive measurements of capacitance and dissipation factor on cable polymers, and potentially suitable for in situ cable monitoring, is introduced.Correlating values of elongation-at-break, indenter modulus, capacitance and dissipation factor measured on a set of 47 aged flame-resistant EPR samples shows a higher correlation between indenter modulus and dissipation factor than between indenter modulus and elongation-at-break.

Polypropylene/Ethylene–Propylene–Diene Terpolymer Blends

2008 ◽  
pp. 411-440
Author(s):  
Chang-Sik Ha ◽  
Subhendu Ray Chowdhury ◽  
Gue-Hyun Kim ◽  
Il Kim
Keyword(s):  
Ethylene Propylene ◽  
Ethylene Propylene Diene Terpolymer
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