The morphology evolution of binary blends subjected to a two-step quench in the presence of external surfaces, such as a static substrate or immobile fillers, was studied using the cell dynamical system (CDS) simulation method. When the binary blends were first annealed at a shallow quench for a long time followed by a second further deep quench into a two-phase region, transient lamellar structures were formed in the blends with both critical and off-critical compositions. The occurrence of the lamellar structure was found to be correlative with the compositional difference between the separated phases formed during the first shallow quench as well as the quench depth of the second quench. For blends contacted with a selective substrate or fillers, well-defined layer structures or target-like compositional waves which were paralleled to the external surfaces were formed during the two-step quench. In these systems, the bulk lamellar structure was affected by the concentration of components and fillers in the blend. The simulation by CDS demonstrated that the combination of various quench conditions and external surfaces play an important role in the pattern formation of binary blend, and provide a new approach in tailoring the morphologies of binary blends in addition to the other available methods.

Three polypropylene (PP) matrices with different intrinsic toughness were used to study the morphology and mechanical properties of polypropylene filled with nano-sized calcium carbonate particles. PP1 was a homopolymer, PP2 was a propylene-ethylene copolymer, and PP3 was a mixture of PP1 and PP2 (PP1:PP2=1:1, weight ratio). The precipitated calcium carbonate (CC0.07) with an average particle size of 0.07 μm was used. Only the yield strength of PP1 nanocomposites filled with low CC0.07 contents (from 2 to 10 wt.%) could increase. When the CC0.07 content was appropriate, the impact strength of all three PP nanocomposites could improve. It was interesting that the intrinsic toughness of PP matrix would influence the toughening effect of the nanoparticles. Only in the case of the moderate matrix toughness (PP3 matrix), the nanocomposites could receive the highest extent of toughness increase (4.3 times that of matrix).

The phase behavior of near-critical PVME/SAN blend in thin film was studied by time-resolved small-angle light scattering (SALS) and atomic force microscopy (AFM). The phase diagram showed that PVME/SAN99 blend had the lower critical solution temperature (LCST), the LCST and the critical composition was 119 °C, 74 wt.% PVME, respectively. However, the cloud points of this system were hard to be obtained before the decomposition of PVME when the weight fraction of SAN99 was more than 50 wt.%. Both SALS and AFM results confirmed that, for PVME/SAN99 blend, there was certainly a transition from homogeneous nucleation and growth to nonlinear spinodal decomposition in the twophase region of 3D Ising regime. For 80/20 PVME/SAN99 blend, during the phase separation, the small orientation of SAN99 domains took place at the early stage of phase separation, and finally disappeared when the phase separation finished. But for 70/30 PVME/SAN99 blend, the orientation did not appear.

The phase behavior of blends of SAN/PVME in film is studied by Time-resolved Small-angle light scattering (SALS) and Atomic force microscopy (AFM). The phase diagram shows that both SAN99 (styrene volume fraction is 0.99)/PVME and SAN97 (styrene volume fraction is 0.97)/PVME have the lower critical solution temperature (LCST), the LCST of SAN97/PVME is (117℃) lower than that (119℃) of SAN99/PVME, and the cloud points of these two systems are hard to be obtained before the decomposition of PVME when the weight fraction of SAN (SAN99 or SAN97) is more than 50 wt%. For 20/80 SAN97/PVME and 20/80 SAN99/PVME blends (80 wt% PVME), although the experimental temperature is higher than the phase separation temperature, the phase separation does not take place immediately. It takes a period of time before the phase separation. The AFM phase images of 20/80 SAN99/PVME blend show that, as the phase separation proceeds, very small SAN99-rich droplets appear, the droplets become large step by step, then two large droplets coalesce into one larger droplet, and the obtained droplet size distribution is broader. Both SALS and AFM results show that, during the phase separation, the very small orientation of SAN domains takes place at the early stage of phase separation, and finally disappears when the phase separation finishes.

The miscibility of binary polymer blends of polystyrene/poly(styrene-co-acrylonitrile) (PS/SAN) was predicted based on both Flory's equation of state theory (EOS) and Wolf's theory on binary polymer blends of the A/A-B type. The calculating results suggested that PS/SAN blend exhibits the upper critical solution temperature (UCST) behavior within acrylonitrile's volume fraction range of 4-20%. PS/SAN blends were studied with the Small Angle Light Scattering (SALS) method to test the theoretical prediction. It showed that PS/SAN (AN:20 vol.%) blend (49/51 wt.%) displays UCST behavior and the UCST temperature was about 171 8C. The calculating and the experimental results were in accordance with each other relatively well.

采用流变法、抽提法以及扫描电镜3种表征方法研究了亲水性纳米二氧化硅粒子SiO2填充对聚甲基丙烯酸甲酯（PMMA）/聚苯乙烯（PS）不相容体系共连续范围的影响。对于未填充PMMA/PS体系，3种方法测得的共连续范围基本一致。而对于粒子填充体系，SEM与溶剂抽提法均表明随着粒子含量的增加，体系的共连续范围变宽，这是由于亲水性SiO2粒子选择性填充在极性PMMA相中，导致PMMA相的熔体粘度和弹性均有大幅提高，从而减缓了破坏共连续结构的纤维断裂或回缩等松弛过程。与SEM法和溶剂抽提法相反，流变法测得的共连续范围随粒子含量增加明显变窄，这主要是因为加入SiO2粒子后，PMMA/PS体系的弹性模量和黏度大大提高（加入7vol%的SiO2后分别增加近50倍和5倍），导致填充试样在装样和设定间距之后需要更长的松弛时间才能开始流变测试。试样在测试前长时间处于高温熔体状态时，其共连续结构很容易在界面张力的驱动下发生粗化和破碎，所以得到的共连续反而变窄。SEM和溶剂抽提法比流变法更适合用来判断粒子填充PMMA/PS体系特别是其高填充体系的共连续范围。

利用自制的激光散射流变仪研究了聚苯乙烯/聚甲基乙烯基醚（PS/PVME）（重量比30/70）二元共混物在振荡剪切场下的相分离动力学过程。在特定的振荡频率和应变振幅条件下，共混物的相分离具有显著的周期特性和各向异性。在同一个振荡相位角条件下，相分离在早期符合经典的Cahn-Hilliard线性理论。在相分离过程中，流动方向上的特征波数Qxm表现出明显的受迫振荡特征而涡流方向上的Qxm却没有；同时，两个方向上的特征波数Qm平均值都未随时间发生变化，说明特定振荡频率和应变振幅的振荡剪切对特定尺寸的浓度涨落具有选择作用。研究还发现，体系的应力响应可以反映出相分离的阶段性过程，例如当相分离早期结束时，表征弹性的第一法向应力差出现了峰值。