Successive self-nucleation and annealing (SSA) technique based on calorimetry is utilized to reveal the effect of uniaxial tensile stress on the photo-oxidation of high density polyethylene (HDPE). Stress-induced acceleratory and inhibitory effects on HDPE are confirmed by analyzing the newly formed melting peaks at low temperatures and the gradually disappeared melting peaks at high temperatures on the SSA curves. The formation of short chains due to chain scission contributes to both the new higher melting peaks (thick lamellae) and lower melting peaks (thin lamellae) because of high mobility and thermodynamic preference, respectively. Besides, chain crosslinking also gives rise to the formation of low melting peaks due to the decrease in the crystallizable sequence lengths and dynamical constraints. Compared with Fourier Transform Infrared Spectrometry, Scanning Electron Microscopy and Small Angle X-ray Scattering, the SSA technique can more precisely and sensitively reflect the early multi-scale aging behavior of HDPE subjected to stress.

利用基于量热法的连续自成核和退火（SSA）技术揭示了单轴拉伸应力对高密度聚乙烯（HDPE）光氧化的影响。通过在SSA曲线上分析在低温下新形成的熔融峰和在高温下逐渐消失的熔融峰，可以确认应力诱导的对HDPE的促进和抑制作用。由于断链而形成的短链分别由于高迁移率和热力学偏好而分别导致了新的较高的熔融峰（较厚的薄片）和较低的熔融峰（较薄的薄片）。此外，由于可结晶序列长度的减少和动力学限制，链交联还引起低熔点峰的形成。