Scheiwiller Sage C, Mata Jitendra P, Pozzo Lilo D
Department of Chemical Engineering, University of Washington, Seattle, WA, USA.
Australian Centre for Neutron Scattering (ACNS), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234, Australia.
Soft Matter. 2024 Aug 7;20(31):6247-6265. doi: 10.1039/d4sm00495g.
The nano- and micron scale morphology of poly(3-hexylthiophene) (P3HT) and polystyrene--polyisoprene--polystyrene (PS-PI-PS) elastomeric blends is investigated through the use of ultra-small and small angle X-ray and neutron scattering (USAXS, SAXS, SANS). It is demonstrated that loading P3HT into elastomer matrices is possible with little distortion of the elastomeric structure up to a loading of ∼5 wt%. Increased loadings of conjugated polymer is found to significantly distort the matrix structure. Changes in processing conditions are also found to affect the blend morphology with especially strong dependence on processing temperature. Processing temperatures above the glass transition temperature () of polystyrene and the melting temperature () of the conjugated polymer additive (P3HT) creates significantly more organized mesophase domains. P3HT blends with PS-PI-PS can also be flow-aligned through processing, which results in an anisotropic structure that could be useful for the generation of anisotropic properties ( conductivity). Moreover, the extent of flow alignment is significantly affected by the P3HT loading in the PS-PI-PS matrix. The work adds insight to the morphological understanding of a complex P3HT and PS-PI-PS polymer blend as conjugated polymer is added to the system. We also provide studies isolating the effect of processing changes aiding in the understanding of the structural changes in this elastomeric conjugated polymer blend.
通过使用超小角和小角X射线及中子散射（USAXS、SAXS、SANS）研究了聚（3-己基噻吩）（P3HT）与聚苯乙烯-聚异戊二烯-聚苯乙烯（PS-PI-PS）弹性体共混物的纳米和微米尺度形态。结果表明，在高达约5 wt%的负载量下，将P3HT负载到弹性体基质中时，弹性体结构几乎不会变形。发现共轭聚合物负载量增加会显著扭曲基质结构。还发现加工条件的变化会影响共混物形态，尤其强烈依赖于加工温度。高于聚苯乙烯的玻璃化转变温度（）和共轭聚合物添加剂（P3HT）的熔点（）的加工温度会产生明显更有序的中间相域。P3HT与PS-PI-PS的共混物也可以通过加工实现流动取向，这会导致一种各向异性结构，该结构可能有助于产生各向异性性能（导电性）。此外，流动取向程度受PS-PI-PS基质中P3HT负载量的显著影响。随着共轭聚合物添加到体系中，这项工作为理解复杂的P3HT和PS-PI-PS聚合物共混物的形态提供了见解。我们还提供了隔离加工变化影响的研究，有助于理解这种弹性体共轭聚合物共混物的结构变化。
