Filming process of polystyrene nano-latex (NPS) particles was studied by a combination of various methods. For a constant annealing time of 1 h, the AFM images showed that the deformation and sintering temperatures fo...Filming process of polystyrene nano-latex (NPS) particles was studied by a combination of various methods. For a constant annealing time of 1 h, the AFM images showed that the deformation and sintering temperatures for NFS particles were ca. 90 ℃ and 100 ℃ respectively. In spin-lattice relaxation measurements of solid state NMR, it is found that TIL, T1S and /1L/I0 increased significantly after annealing at 90℃ and above. DSC results showed that there was an exothermic peak near Tg after annealing for 1 h at the selected temperatures below 95℃; otherwise, the exothermic peak disappeared after annealing at 100℃ or above. The apparent density of NPS increased suddenly in the temperature range. The results implied that the macromolecules in NPS particles are in a confined state with higher confor-mational energy and less cohensional interactions which are the drive force for the sintering at a lower temperature compared with the multichain PS particles and the bulk polymer.展开更多
基金This work was supported by the National Key Project for Fundamental Research the State Science and Technology Commission of China (Grant No. 95-11) and the National Natural Science Foundation of China (Grant Nos. 20004011 and 20023003).
文摘Filming process of polystyrene nano-latex (NPS) particles was studied by a combination of various methods. For a constant annealing time of 1 h, the AFM images showed that the deformation and sintering temperatures for NFS particles were ca. 90 ℃ and 100 ℃ respectively. In spin-lattice relaxation measurements of solid state NMR, it is found that TIL, T1S and /1L/I0 increased significantly after annealing at 90℃ and above. DSC results showed that there was an exothermic peak near Tg after annealing for 1 h at the selected temperatures below 95℃; otherwise, the exothermic peak disappeared after annealing at 100℃ or above. The apparent density of NPS increased suddenly in the temperature range. The results implied that the macromolecules in NPS particles are in a confined state with higher confor-mational energy and less cohensional interactions which are the drive force for the sintering at a lower temperature compared with the multichain PS particles and the bulk polymer.
