Thermally-healable network solids of sulfur-crosslinked poly(4-allyloxystyrene).
Thermally-healable network solids of sulfur-crosslinked poly(4-allyloxystyrene).
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硫 - 跨链接聚（4-乙酸酯）的热可连续网络固体。
DOI：
10.1039/c8ra06847j
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发表时间：
2018-11-16
期刊：
影响因子：
3.9
通讯作者：
Tennyson, Andrew G.
中科院分区：
文献类型：
--
作者：
Thiounn, Timmy;Lauer, Moira K.;Bedford, Monte S.;Smith, Rhett C.;Tennyson, Andrew G.
通过聚4-烯丙氧基苯乙烯与热均裂开环的S8在硫醇-烯型反应中反应制备了硫和聚4-烯丙氧基苯乙烯的网状聚合物PAOSx（x =硫的质量百分比，其中x在10-99之间变化）。硫含量和交联影响热/机械性能的程度进行了评估。发现具有低于50%的硫含量的网络材料是热固性的，而具有>90%的硫含量的那些是可热愈合的和可再熔的。DSC分析显示，低硫含量的材料在-50至140 °C之间既没有Tg也没有Tm，而高硫含量的材料的Tg或Tm值与硫的量成比例。DSC数据还显示PAOS 90的富硫区由硫交联的有机聚合物和无定形硫组成，而PAOS 99的富硫区主要由α-硫（正交硫）组成。通过CS2浸提和可浸提/不可浸提部分的分析进一步证实了这些结论。基于TGA、FT-IR、H2S捕集实验、CS2可提取质量和元素燃烧微量分析数据的计算用于评估游离硫和交联硫的相对百分比以及每个交联的S原子平均数。动态力学分析表明，PAOS 90和PAOS 99具有高储能模量（在−37 °C下分别为3和6 GPa），机械Tg在−17 °C和5 °C之间。PAOS 99样品在至少12次粉碎-热愈合循环后仍保持其完整的初始机械强度，使其成为易于修复和可回收的候选材料。将硫和聚苯乙烯衍生物组合以形成可热修复和可回收的复合材料，其与单独的硫相比具有显著增加的结构完整性。
Network polymers of sulfur and poly(4-allyloxystyrene), PAOSx (x = percent by mass sulfur, where x is varied from 10–99), were prepared by reaction between poly(4-allyloxystyrene) with thermal homolytic ring-opened S8 in a thiol-ene-type reaction. The extent to which sulfur content and crosslinking influence thermal/mechanical properties was assessed. Network materials having sulfur content below 50% were found to be thermosets, whereas those having >90% sulfur content are thermally healable and remeltable. DSC analysis revealed that low sulfur-content materials exhibited neither a Tg nor a Tm from −50 to 140 °C, whereas higher sulfur content materials featured Tg or Tm values that scale with the amount of sulfur. DSC data also revealed that sulfur-rich domains of PAOS90 are comprised of sulfur-crosslinked organic polymers and amorphous sulfur, whereas, sulfur-rich domains in PAOS99 are comprised largely of α-sulfur (orthorhombic sulfur). These conclusions are further corroborated by CS2-extraction and analysis of extractable/non-extractable fractions. Calculations based on TGA, FT-IR, H2S trapping experiments, CS2-extractable mass, and elemental combustion microanalysis data were used to assess the relative percentages of free and crosslinked sulfur and average number of S atoms per crosslink. Dynamic mechanical analyses indicate high storage moduli for PAOS90 and PAOS99 (on the order of 3 and 6 GPa at −37 °C, respectively), with a mechanical Tg between −17 °C and 5 °C. A PAOS99 sample retains its full initial mechanical strength after at least 12 pulverization-thermal healing cycles, making it a candidate for facile repair and recyclability. Sulfur and a polystyrene derivative were combined to form thermally-healable and recyclable composite materials with dramatically increased structural integrity versus sulfur alone.
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影响因子：
7.015
作者：
Griebel, Jared J.;Nguyen, Ngoc A.;Pyun, Jeffrey
通讯作者：
Pyun, Jeffrey
DOI：
10.1021/i360055a009
发表时间：
1975-01-01
期刊：
INDUSTRIAL & ENGINEERING CHEMISTRY PRODUCT RESEARCH AND DEVELOPMENT
影响因子：
--
作者：
LEE, DY
通讯作者：
LEE, DY
影响因子：
7.015
作者：
Kleine, Tristan S.;Nguyen, Ngoc A.;Pyun, Jeffrey
通讯作者：
Pyun, Jeffrey
影响因子：
2.6
作者：
Ferreira, A. G. M.;Lobo, L. Q.
通讯作者：
Lobo, L. Q.
影响因子：
3.7
作者：
AKAHAMA, Y;KOBAYASHI, M;KAWAMURA, H
通讯作者：
KAWAMURA, H