摘要
用MSL—400核磁共振(NMR)波谱仪记录了尼龙6的^(13)C交叉极化魔角旋转(CP/MAS)NMR谱,发现固态下ω碳原子有两个峰,尼龙6记为ω_1和ω_2。在同一样品的^(13)C NMR溶液谱中,这两个峰合并成一个峰,证明固态尼龙6中两种晶区是共存的。在固态,ω_2峰比ω_1峰向高场偏移2.2ppm。测量了尼龙6—系列不同接触时间的CP/MAS NMR谱以研究动态行为。用SIMPLEX非线性最小二乘法拟合技术计算了交叉极化速率和质子T_(1ρ)~H用Ngai公式计算了固态尼龙6的运动参数。
C-13 CP/MAS spectra of nylon 6 were obtained on MSL-400 spectrometer. It was found that the ω carbon
α β γ δ ω
-[CO-CH2-CH2-CH2-CH2-CH2-NH]-n , nylon 6,
shows two peaks in the solid state. They are designated asω1 and ω2 which originate from different crystalline components. The two peaks coalesced in solution spectrum of the same sample. It gives the evidence of coexistence of different crystalline regions in solid nylon 6. In the solid state the ω2 peak is 2. 2 ppm upfield from the ω1 peak.
A series of CP/MAS spectra of nylon 6 was measured by varying the contact time to investigate the dynamic behavior. A SIMPLEX nonlinear least square optimization algorithm was applied to calculate the cross-polarization rates TIS and TIP^H. The dynamic parameters of solid nylon 6 were calculated according to Ngai formalism.
出处
《波谱学杂志》
CAS
CSCD
1989年第4期461-468,共8页
Chinese Journal of Magnetic Resonance
基金
National Natural Science Fundation of China
