A solid-state NMR study of structure and segmental dynamics of poly(propylmethacryl-heptaisobutyl-pss)-co-styrene nanocomposites.
A solid-state NMR study of structure and segmental dynamics of poly(propylmethacryl-heptaisobutyl-pss)-co-styrene nanocomposites.
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DOI：
10.1016/j.jcis.2010.12.044
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发表时间：
2011-03
影响因子：
9.9
通讯作者：
Qin Zou;Limin Zhang;Shenhui Li;Xiuzhi Gao;F. Deng
中科院分区：
文献类型：
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作者：
Qin Zou;Limin Zhang;Shenhui Li;Xiuzhi Gao;F. Deng
利用固体核磁共振技术结合X射线衍射技术研究了不同多面体低聚倍半硅氧烷（POSS）含量的聚甲基丙烯酸-七异丁基-聚苯乙烯（PP-PSS）-co-苯乙烯（PS）纳米复合材料的微区结构和运动性。核磁共振弛豫时间的测定表明，POSS含量的增加有使PS单元中的链运动的趋势。虽然XRD结果表明POSS很好地分散在聚合物基体中，但2DWISE NMR表明POSS在聚合物基体中的分散导致了由刚性和密集堆积的PS微区和移动的和无定形的POSS微区组成的复合结构。这意味着两个领域的规模非常小。二维HETCOR NMR表明，随着POSS含量的增加，PS网络与POSS单元之间的距离逐渐减小。通过2D自旋扩散NMR实验确定的分散POSS域的大小随着POSS负载量的增加而增加，对于POSS 15、POSS 25和POSS 45纳米复合物，分别为约3.0、3.9、6.0nm。
The domain structure and mobility of poly(propylmethacryl-heptaisobutyl-pss)-co-styrene nanocomposites with different polyhedral oligomeric silsesquioxane (POSS) contents were investigated by various solid-state NMR techniques in combination with XRD. The NMR relaxation time measurements suggested that increasing POSS content trended to mobilize the chains in PS unit. Although XRD results showed that POSS was well dispersed into the polymer matrix, 2D WISE NMR indicated that the dispersion of POSS into the polymer matrix led to a composite structure composed of rigid and densely packed PS domain and mobile and amorphous POSS domain. This implied that the size of the two domains was very small. 2D HETCOR NMR implied that the distance between PS network and POSS unit gradually decreased when the POSS content successively increased. The dispersed POSS domain size determined by 2D spin-diffusion NMR experiments was increased with the POSS loading, being about 3.0, 3.9, 6.0nm for the POSS15, POSS25 and POSS45 nanocomposites, respectively.