Lee Sang-In, Seo Min-Guk, Huh June, Paik Hyun-Jong
Department of Polymer Science and Engineering, Pusan National University, Busan 46241, Republic of Korea.
LX MMA R&D Center, 188, Munji-ro, Yuseong-gu, Daejeon 34122, Republic of Korea.
Polymers (Basel). 2023 Jun 30;15(13):2915. doi: 10.3390/polym15132915.
We investigated the segregation behavior of a molten diblock copolymer, poly(-butyl acrylate)--poly(methyl methacrylate--styrene) (PBA--P(MMA--S)), wherein styrene (S) is incorporated as a comonomer in the second block to modulate the effective interaction between homopolymer and a random copolymer block. The temperature dependence of the effective interaction parameter χeff between -butyl acrylate (BA) and the average monomer of the MMA--S random block was evaluated from small-angle X-ray scattering (SAXS) analysis using the random phase approximation (RPA) approach. The calculated χeff, as a function of the styrene fraction in the random copolymer block, shows a good agreement with the mean-field binary interaction model. This consistency indicates that the effective interaction between component BA and the average monomer of the random copolymer block is smaller than the interactions between pure components (χBA,MMA,χBA,S). The present study suggests that the introduction of a random copolymer block to a block copolymer can effectively reduce the degree of incompatibility of the block copolymer system without altering the constituent species, which may serve as a viable methodology in designing novel thermoplastic elastomers based on triblock or multiblock copolymers.
我们研究了一种熔融二嵌段共聚物聚（丙烯酸丁酯）-聚（甲基丙烯酸甲酯-苯乙烯）（PBA-P（MMA-S））的相分离行为，其中苯乙烯（S）作为共聚单体引入第二嵌段，以调节均聚物与无规共聚物嵌段之间的有效相互作用。使用随机相位近似（RPA）方法，通过小角X射线散射（SAXS）分析评估了丙烯酸丁酯（BA）与MMA-S无规嵌段的平均单体之间有效相互作用参数χeff的温度依赖性。计算得到的χeff作为无规共聚物嵌段中苯乙烯含量的函数，与平均场二元相互作用模型吻合良好。这种一致性表明，组分BA与无规共聚物嵌段的平均单体之间的有效相互作用小于纯组分之间的相互作用（χBA,MMA，χBA,S）。本研究表明，在不改变组成物种的情况下，向嵌段共聚物中引入无规共聚物嵌段可以有效降低嵌段共聚物体系的不相容程度，这可能是设计基于三嵌段或多嵌段共聚物的新型热塑性弹性体的一种可行方法。
