摘要
以连续共混过程间歇出料法研究了PS/PcBR非相容体系共混过程中的扫描电子显微镜图样演化过程 ,从平均粒径、特征长度Λ和平均特征长度Λm 多个方面讨论了非相容体系的共混过程 ,并以标度函数P(Λ/Λm)证明非相容体系共混过程在一定时间和空间范围内具有自相似性 。
The phase forming and development of polystyrene/poly( cis-butadiene) rubber (weight ratios were 70/30 and 50/50, respectively) blends during mixing were investigated by pattern analysis of scanning electron microscope. For the blend with composition 70/30, the average diameter (PDav) of the dispersed phase [particles (PcBR)] decreased in the initial stage of mixing, and fluctuated in the metaphase and later stage. The distribution of the particles trended to uniform with the blending process. But for the blend with composition 50/50, which is near the phase inversion composition, the calculation of PDav is difficult because of the co-continuous structure of the two components, thus two parameters, the characteristic length Lambda and the average characteristic length Lambda (m) are used to characterize the size of the dispersed phase. The characteristic length was defined as the measuring distance of black area (dispersed phase) when scanned the binarized SEM images along a direction. The changes of Lambda (m) was similar to that of PDav, and the Lambda and Lambda (m) could reflect the size and size distribution of the dispersed phase whether or not the composition is near the phase inversion. Furthermore, the histograms of Lambda (m) obtained at various time in the metaphase and later stage of mixing fell on a master curve, demonstrating the self-similar growth of the phase structure. Thus a scale function P (Lambda/Lambda (m)) was defined to study the fractal. behavior of the mixing. The results showed that the fractal dimension D could be used to characterize the mixing process of the polymer blend.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2001年第2期219-223,共5页
Acta Polymerica Sinica
基金
国家自然科学重点基金 !(基金号 5 973 3 0 70 )资助项目
