壳层交联的纳米聚集体中高分子的受限结晶与熔融行为研究

Discrete nano-aggregates of a poly(ethylene oxide)-b-polybutadiene diblock copolymer (PEO-b-PB) were obtained by self-assembling of the copolymer in a selective solvent of PB followed by the shell cross-linking.The average behaviors of the PEO crystallization and melting confined within the nano-structured aggregates were studied by differential scanning calorimetry experiments.The experiments demonstrated that the confinement effect arisen from the shells could be tuned by adjusting the degree of PB cross-linking.For the deeply cross-linked sample,the individual particles only crystallized at very low crystallization temperature (T c),wherein the homogenous primary nucleation determined the crystallization rate.For the lightly cross-linked sample,the confinement effect is T c dependent.When T c exceeded 42℃,the lightly cross-linked sample possessed a higher melting temperature and a lower crystallinity compared with the pure PEO-b-PB.