Relationship between free volume and mechanical properties of polyurethane irradiated by gamma rays

Sui, Heliang; Liu, Xueyong; Zhong, Fachun; Li, Xiaoyan; Wang, Boyu; Ju, Xin

doi:10.1007/s10967-014-3048-7

Cited by 5 publications

(2 citation statements)

References 15 publications

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“…Were the movements of chain segments easy enough, the generation and quenching of free radicals tend to be balanced during irradiation. 21 The fluidity of polymer at any temperature is related to the fraction of the free volume, and hence the free volume theory is often used to explain the plasticization mechanism. The larger the free volume, the better the mobility of polymer chain.…”

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confidence: 99%

“…22 Since the mobility of polymer chains is dependent on the free volume strongly, the irradiation resistance of polymer is also related to the free volume. 21 On the other hand, the free volume is commonly used as scale to correlate structural changes and performance of polymers after aging (including γ ray, ion irradiation, and UV radiation, etc.). [23][24][25] Therefore, to establish relations between molecular structures of lead-containing plexiglass and its final irradiation resistance to discoloration using the alterations of free volume as probe is of challenge, and also meaningful to regulate final performance of leadcontaining plexiglass.…”

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confidence: 99%

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Insight into the role of free volume in irradiation resistance to discoloration of lead‐containing plexiglass

Zhang

Chen

Zhao

et al. 2021

J of Applied Polymer Sci

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Lead‐containing plexiglass is prepared successfully via copolymerization of lead‐methacrylate (Pb(MAA)2 and the acrylic monomer such as methyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate. The results show that as‐prepared plexiglass has good photons shielding performance and resistance to the discoloration induced by radiation (10 kGy γ‐ray), and the alteration of shielding performance can be well described by the Monte Carlo Code simulations (MCNP5). Using two plasticized systems, the external‐plasticized one with various n‐octanoic acid concentrations and the internal‐plasticized one with different acrylic monomer, as the target samples, it is found that free volume plays dominant role in the irradiation resistance via the positron annihilation lifetime spectroscopy and electron paramagnetic resonance characterizations. The larger the free volume, the greater the quenching probability of free radicals during irradiation. Because the primary type of radiation‐induced color centers are annealable color centers, the effect of annealing of irradiation‐induced discoloration of lead‐containing plexiglass is remarkable. Differing from common treatments of improving irradiation resistance, the increased free volume via plasticization gives plexiglass good resistance to discoloration. This study discloses valuable information around improving irradiation shielding performance and resistance to the radiation‐induced discoloration for the plexiglass‐based materials.

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confidence: 99%