私密直播全婐app免费大渔直播,国产av成人无码免费视频,男女同房做爰全过程高潮,国产精品自产拍在线观看

相關(guān)鏈接
聯(lián)系方式
  • 通信地址:陜西省西安市友誼西路127號(hào)
  • 郵編:710072
  • 電話:029-88431638
  • 傳真:
  • Email:nwpugjw@163.com
當(dāng)前位置:> 首頁(yè) > 最新動(dòng)態(tài) > 正文
SFPC課題組本征導(dǎo)熱高分子材料工作發(fā)表在Polymer Chemistry上

Jinjin Dang, Junliang Zhang*, Mukun Li, Lin Dang and Junwei Gu*. Enhancing intrinsic thermal conductivities of epoxy resins by introducing biphenyl mesogen-containing liquid crystalline co-curing agents. Polymer Chemistry, 2022, 13(42): 6046-6053. 2021IF=5.364.

https://doi.org/10.1039/D2PY01157C

Abstract

In this work, a biphenyl liquid crystalline small molecule (BLCM) containing flexible units was synthesized via a one-step condensation reaction of 4,4′-dihydroxybiphenyl (BP) and 1,6′-dibromohexene. Then, the commercially available bisphenol A epoxy (E-51) was used as a matrix, 4,4′-diaminodiphenylmethane (DDM) as a curing agent, and the BLCM as a co-curing agent to prepare highly intrinsic thermally conductive liquid crystalline epoxy resins (LCER) by a casting method. Nuclear magnetic resonance spectroscopy, high-resolution mass spectroscopy, and Fourier transform infrared spectroscopy demonstrated that the BLCM with a designed structure was synthesized successfully. Wide-angle X-ray diffraction, small-angle X-ray scattering, and polarized light microscopy proved that the inter-stacking of biphenyl mesogens promoted the formation of locally ordered regions in the LCER. Meanwhile, the ordered structure of the LCER was enhanced with an increase of the BLCM mass fraction, resulting in the higher intrinsic thermal conductivity. When the mass fraction of the BLCM was 60% of E-51 (LCER3), the thermal conductivity (λ) of LCER3 was 0.42 W/(m·K), which was 2.1 times that of an epoxy resin cured with DDM only (LCER0, λwas 0.20 W/(m·K)). Besides, LCER3 presented a high heat resistance index (THRI) of 176.8°C, elastic modulus of 4.8 GPa, and hardness of 0.32 GPa, which was also higher than LCER0 with a THRI of 172.2°C, elastic modulus of 3.7 GPa, and hardness of 0.27 GPa.

本文以通用雙酚A環(huán)氧樹脂(E-51)為基體、4,4’-二氨基二苯甲烷(DDM)為固化劑,以4,4’-二羥基聯(lián)苯(BP)和1,6’-二溴己烯一步縮合反應(yīng)合成的含柔性基團(tuán)的聯(lián)苯型液晶單體(BLCM)為共固化劑,經(jīng)澆注固化制備本征高導(dǎo)熱液晶環(huán)氧樹脂(LCER)。核磁共振和傅里葉變換紅外光譜證明具有預(yù)期結(jié)構(gòu)的BLCM已成功合成。廣角X射線衍射和偏光顯微鏡證明聯(lián)苯液晶基元間的相互堆疊促使局部有序結(jié)構(gòu)的形成,且LCER的結(jié)構(gòu)有序度隨BLCM質(zhì)量分?jǐn)?shù)的增加而增強(qiáng)。當(dāng)BLCM的質(zhì)量分?jǐn)?shù)為E-51的60%時(shí),LCER3的導(dǎo)熱系數(shù)(λ)為0.42 W/(m·K),是僅用DDM固化的環(huán)氧樹脂(LCER0)λ(0.20 W/(m·K))的2.1倍。此外,LCER3兼具良好的熱穩(wěn)定性和力學(xué)性能,其耐熱指數(shù)(THRI)、彈性模量和硬度分別為176.8oC、4.8 GPa和0.32 GPa,也均優(yōu)于相應(yīng)的LCER0(THRI=172.2oC,彈性模量和硬度分別為3.7 GPa和0.27 GPa)。


本文亮點(diǎn)

1. 核磁共振和傅里葉變換紅外光譜證明具有預(yù)期結(jié)構(gòu)的BLCM已成功合成。廣角X射線衍射和偏光顯微鏡證明聯(lián)苯液晶基元間的相互堆疊促使局部有序結(jié)構(gòu)的形成,且LCER的結(jié)構(gòu)有序度隨BLCM質(zhì)量分?jǐn)?shù)的增加而增強(qiáng)。

2. 當(dāng)BLCM的質(zhì)量分?jǐn)?shù)為E-51的60%時(shí),LCER3的導(dǎo)熱系數(shù)(λ)為0.42 W/(m·K),是僅用DDM固化的環(huán)氧樹脂(LCER0)λ(0.20 W/(m·K))的2.1倍。

3. LCER3兼具良好的熱穩(wěn)定性和力學(xué)性能,其耐熱指數(shù)(THRI)、彈性模量和硬度分別為176.8oC、4.8 GPa和0.32 GPa,也均優(yōu)于相應(yīng)的LCER0(THRI=172.2oC,彈性模量和硬度分別為3.7 GPa和0.27 GPa)。


第一作者:黨金金

郵件地址:nwpudangjinjin@163.com

主站蜘蛛池模板: 洪洞县| 和林格尔县| 六枝特区| 隆子县| 布尔津县| 徐水县| 常宁市| 新乡市| 车致| 柳州市| 河北省| 邵东县| 马公市| 滨海县| 天全县| 河津市| 烟台市| 江达县| 昌图县| 南丹县| 得荣县| 黔东| 开化县| 重庆市| 土默特左旗| 昆山市| 枣阳市| 田林县| 武功县| 紫阳县| 东丽区| 四平市| 平乡县| 陈巴尔虎旗| 日照市| 当涂县| 芜湖市| 伊春市| 长丰县| 克山县| 黄山市|