Since the advent of 5G network, polymeric low dielectric constant (low‐k) materials have been indispensable for high speed and stable signal transmission at microwave frequency. Herein, the low‐k composites of 1,2‐polybutadiene/styrene‐butadiene‐styrene triblock copolymer/ethylene‐propylene‐dicyclopentadiene (1,2‐PB/SBS/EPDM) were prepared with cured organic peroxide. Two structurally different organic peroxides, namely dicumyl peroxide (DCP) and bis(1‐(tert‐butylperoxy)‐1‐methylethyl)‐benzene (BIPB), were used as free‐radical initiators. The composites with highly efficient initiator—BIPB exhibited considerably enhanced conversion rate, thermal stability, and cross‐link density compared with the DCP system. Furthermore, the increased cross‐link density contributed to dielectric stability over a broad range of frequency (3‐15 GHz) and superior mechanical properties. The cross‐linked composites possessed the typical low polarity group of C─C single bond with suppressed dielectric constant (D_k) and loss (D_f). Especially, the average D_k of 2.36 and average D_f of 0.0054 were obtained for the composite containing 4 part‐by‐weight (pbw) BIPB. This work demonstrated that the 1,2‐PB/SBS/EPDM composite with 4 pbw BIPB is a good candidate for high‐frequency substrate materials.

中文翻译：

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用于固化高频基材的低k 1,2-PB / SBS / EPDM复合材料的不同有机过氧化物

自5G网络问世以来，聚合低介电常数（low- k）材料对于在微波频率下实现高速和稳定的信号传输一直是必不可少的。这里，低k用固化的有机过氧化物制备1,2-聚丁二烯/苯乙烯-丁二烯-苯乙烯三嵌段共聚物/乙烯-丙烯-二环戊二烯的复合材料（1,2-PB / SBS / EPDM）。两种结构不同的有机过氧化物，即过氧化二枯基（DCP）和双（1-（叔丁基过氧）-1-甲基乙基）-苯（BIPB）被用作自由基引发剂。与DCP系统相比，具有高效引发剂BIPB的复合材料的转化率，热稳定性和交联密度显着提高。此外，增加的交联密度有助于在较宽的频率范围（3-15 GHz）和优异的机械性能中保持介电稳定性。交联的复合材料具有典型的C‑C单键低极性基团，且介电常数（D _k）和损失（D _f）。尤其是，含有4重量份（pbw）BIPB的复合材料的平均D _k为2.36，平均D _f为0.0054。这项工作表明，具有4 pbw BIPB的1,2-PB / SBS / EPDM复合材料是高频衬底材料的理想选择。