Fig. 1. Primary mechanism of action of γ-ray irradiation on polymer chains,with blue lines representing polymer chains,green dots representing crosslinks,and red dots representing scissions

Fig. 2. Frequency dependence of G′,G″,and η* at 200 °C for (a) original HDPE and (b) XL-HDPE with total absorbed dose of 50 kGy^[19]

Fig. 3. Based on the irradiation cross-linked polyethylene system,a one-to-one correlation between flow-induced nucleation morphologies and strain in polyethylene via rheology – SAXS investigation^[19]

Fig. 4. In situ SANS investigation on flow induced crystallization of irradiation cross-linked dPE/PE blend^[22]

Fig. 5. Revisiting the morphology and mechanism of flow-induced crystallization of irradiation cross-linked PE inversely: an in situ swelling SANS study^[24]

Fig. 6. (a) Spherical harmonic expansion of the scattering intensity I(q) for the lightly crosslinked high-density polyethylene after completion of crystallization at 132 ℃ and ε=1.1. The color bars denote the scale of the scattering intensity in arbitrary unit. (b) The associated 1D expansion coefficients $I_l^{\mathrm{0}}\left(\mathit{q}\right)$^[26]

Fig. 7. Model analyses of the spherical harmonic expansion coefficients for the SAXS spectra of shish in (a) hexagonal and (b) sparse packing. Here,we fit $I_{\mathrm{2}}^{\mathrm{0}}\left(q\right)$ and $I_{\mathrm{4}}^{\mathrm{0}}\left(q\right)$ simultaneously,and calculate the model curves of $I_{\mathrm{0}}^{\mathrm{0}}\left(q\right)$,$I_{\mathrm{6}}^{\mathrm{0}}\left(q\right)$,and $I_{\mathrm{8}}^{\mathrm{0}}\left(q\right)$ with the parameters determined from the fit. The arrow in panel (a) denotes the bump arising from the ordering of shish packing. The insets in panels (a) and (b) are schematic diagrams of the shish model for above two conditions

Fig. 8. Time evolution of lamellar growth for the lightly crosslinked high-density polyethylene melt. The inset is the schematic diagram of the transfer of crystallizable chains for the formation of lamellae,where the red arrows denote the diffusion direction of crystallizable chains (color online)

Fig. 9. Correlation between mechanical properties and microscopic structures of an optimized silica fraction in irradiation-cured silicone rubber^[39]