Hot Set Characterization of Electron Beam Irradiated-Copper (II) Oxide Added LDPE Composites under Acidic Aging

2015 ◽  
Vol 786 ◽  
pp. 63-67
Author(s):  
Tiam Ting Tee ◽  
Soo Tueen Bee ◽  
Tin Sin Lee ◽  
Chantara Thevy Ratnam ◽  
Haraveen Kaur Jogindar Singh

In this research study, the effect of aging duration time and electron beam irradiation dosages on the hot set results of copper (II) oxide added LDPE composites have been investigated. The addition of copper (II) oxide particles in LDPE matrix has significantly reduced the formation of crosslinking networks in LDPE matrix by blocking the mobility of free radicals generated by electron beam irradiation. At lower irradiation dosages (< 100 kGy), all the copper (II) oxide added LDPE composites were immediately failed the hot set test when subjected to static load of 20 N/cm2 under high temperature. Besides, the occurrence of copper (II) oxide particles in LDPE matrix also reduced the matrix continuities of copper (II) oxide added LDPE composites and caused the matrix resistance ability of LDPE matrix to be decreased. The increasing of irradiation dosages has significantly delayed the failing time of all LDPE composites when under static load at high temperature. This is because the increasing of electron beam irradiation could further induce the generation of free radicals to form higher degree of crosslinking networks in LDPE matrix. At higher irradiation dosage up to 250 kGy, the pristine LDPE was observed able to withstand the applied static load under high temperature more than 15 minutes. This is due to higher degree of crosslinking networks formed in LDPE matrix could effectively restrict the mobility of LDPE chains under static load and thus delay the failing of sampels. When the aging duration time increased from 4 days to 14 days, the resistance ability of all LDPE has been significantly weakened due to the occurrence of chain scissioning process in LDPE matrix by delaying the failing time of samples.

2007 ◽  
Vol 13 (4) ◽  
pp. 249-257 ◽  
Author(s):  
R. Bhat ◽  
K.R. Sridhar

Electron spin resonance (ESR) spectroscopy was employed to detect free radicals in raw Mucuna pruriens (velvet bean) seeds after electron beam irradiation (Microtron source: 0, 2.5, 5, 7.5, 10, 15 and 30 kGy) and conventional processing (roasting, powdering and cooking). The ESR signal of irradiated seeds (g=2.0055±0.0001) was more prominent in the seed coat than cotyledon. Seed coat of irradiated samples showed dose-dependent linear increase of this signal (g = 2.0055) accompanied by a weak triplet (satellite peak; aH = 3 mT) produced exclusively by radiolysis and could be used as an indication of successful irradiation. Irradiated cotyledon portion devoid of satellite peak (triplet) showed a linear increase in signal intensity up to 10 kGy with a sharp decline at higher doses (15 and 30kGy). Stability of radiation-induced ESR signals after 6 months of storage (25 ± 1°C) revealed the presence of a weak triplet with a substantial loss of signal intensity. Thermal effects such as roasting and powdering of seeds increased the signal intensity (g = 2.0055) similar to or in greater proportion than irradiation. Phenolics in seeds, which contribute significantly to detect free radicals in vegetative parts of a plant showed a waning trend in seed coat, while it was vice versa in cotyledon. Textural studies revealed significant loss in firmness after irradiation (p<0.05), which might favour in minimising the cooking time. Results of the present study might help to divulge the beneficial effects of application of electron beam irradiation technology as a better alternative to fumigants in seed preservation for safety and quarantine purposes.


2001 ◽  
Vol 16 (2) ◽  
pp. 553-557 ◽  
Author(s):  
Kazuya Oguri ◽  
Nobuhiro Iwataka ◽  
Akira Tonegawa ◽  
Yoichi Hirose ◽  
Kazuo Takayama ◽  
...  

We developed a diamond surface that does not mist near the room temperature under a saturated humidity atmosphere, by sheet electron beam irradiation (SEBI) treatment. SEBI treatment decreased the time to clear vision of the diamond surface. Following SEBI treatment for 1.91 s (= 0.72 MGy) to a diamond surface, the time to clear vision was less than 2 s. The effective duration time was a few hours. Based on the results of the size distribution of the drops on the misting-free diamond surface following blowing for 3 s, we proposed an explanation for the short time to clear vision of the diamond surface treated by SEBI.


2015 ◽  
Vol 30 (7) ◽  
pp. 915-937
Author(s):  
Soo-Tueen Bee ◽  
Lee Tin Sin ◽  
CT Ratnam ◽  
Gin-Khuan Chua ◽  
AR Rahmat

The aim of this research was to investigate the interaction of electron beam irradiation on the different valence of copper (I) and copper (II) oxides (Cu2O and CuO) added low-density polyethylene (LDPE) composites. The results showed the increasing of Cu2O loading level in replacing the CuO has significantly reduced the gel content (or degree of cross-linking networks) in LDPE matrix. This is due to the poorer effect of Cu2O in inducing the polymeric free radicals. Meanwhile, the application of low irradiation dosage (≤100 kGy) has significantly increased the crystallite size for crystallite peak (110) of all LDPE composites. However, further increment in irradiation dosages from 100 to 300 kGy has gradually reduced the crystallite size of deflection peak (110). The tensile strength of all LDPE composites was gradually decreased with increasing of Cu2O loading level due to agglomeration of Cu2O and CuO particles in LDPE matrix. In addition, the increasing of irradiation dosages on all Cu2O /CuO added LDPE composites has gradually increased the tensile strength by inducing the formation of the cross-linking networks in LDPE matrix. Nevertheless, the increasing of irradiation dosage has gradually decreased the elongation at break of all Cu2O /CuO added LDPE composites. This is due to the higher degree of cross-linking networks in LDPE matrix could restrict the mobility of LDPE macromolecular chains when subjected to straining stress.


2011 ◽  
Vol 17 (S2) ◽  
pp. 1502-1503
Author(s):  
H Floresca ◽  
S Mick ◽  
N Lu ◽  
J Wang ◽  
M Kim

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.


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