Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality
Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality
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源自生物基酚酸的具有不同功能的硫醇烯弹性体
DOI：
10.1021/acs.macromol.6b01018
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发表时间：
2016
期刊：
影响因子：
5.5
通讯作者：
Robertson, Megan L.
中科院分区：
文献类型：
--
作者：
Yang, Guozhen;Kristufek, Samantha L.;Link, Lauren A.;Wooley, Karen L.;Robertson, Megan L.
探讨了以植物酚酸为原料合成硫醇烯弹性体的方法及其物理性能。将不同官能度（每分子2至4个羟基和羧基）和官能团的相对位置（邻位、Meta、帕拉）的酚酸烯丙基化，随后使用光引发剂与多官能硫醇反应。对所得弹性体的热性能和力学性能进行了表征。衍生自双官能烯丙基化酚酸的网络表现出窄的玻璃化转变（表明高度的网络均匀性）和玻璃化转变温度（Tg），这与它们的交联密度。烯丙基取代的烯丙基化的酚酸产生的网络具有最高的交联密度，Tg，模量，拉伸强度和断裂伸长率（其次是邻位和间位）。随着烯丙基化单体的官能度增加（至每分子3-4个烯丙基），交联密度保持高，但Tg降低，这归因于整个网络结构中苯环的浓度较低（因为所有网络都是以烯丙基和硫醇官能团的化学计量比制备的）。衍生自较高官能度烯丙基化酚酸的网络还表现出较低的断裂伸长率和相关的拉伸强度和拉伸韧性，这可能是由于网络的不均匀性增加（由与衍生自双官能烯丙基化酚酸的网络相比更高的玻璃化转变宽度指示）。所有网络在低至中等应变下表现出与理想弹性体（仿射网络）一致的行为，尽管模量低于从单体化学结构预测的模量。在达到的应变范围的高端，一些网络表现出应变硬化行为。这项工作开发了酚酸分子结构（包括官能团的数量和位置）与所得网络的物理性质之间的基本关系。
The synthesis and physical properties of thiol–ene elastomers derived from plant-based phenolic acids were explored. Phenolic acids of varying functionality (ranging from 2 to 4 hydroxyl and carboxyl groups per molecule) and relative placement of functional groups (ortho,meta,para) were allylated and subsequently reacted with a multifunctional thiol using a photoinitiator. The thermal and mechanical behaviors of the resulting elastomers were characterized. The networks derived from difunctional allylated phenolic acids exhibited narrow glass transitions (indicating a high degree of network homogeneity) and glass transition temperatures (Tg) which correlated with their cross-link density. Theparaplacement of allyl groups on the allylated phenolic acid produced a network with the highest cross-link density,Tg, modulus, tensile strength, and elongation at break (followed byorthoand thenmeta). As the functionality of the allylated monomer increased (to 3–4 allyl groups per molecule), the cross-link density remained high yet theTgdecreased, attributed to a lower concentration of benzene rings throughout the network structure (as all networks were prepared at the stoichiometric ratio of allyl and thiol functional groups). The networks derived from the higher functionality allylated phenolic acids also exhibited lower elongation at break and associated tensile strength and tensile toughness, likely due to increased heterogeneity of the networks (indicated by higher glass transition widths compared to the networks derived from difunctional allylated phenolic acids). All networks exhibited behavior consistent with an ideal elastomer (affine network) at low to moderate strains, albeit with lower moduli than predicted from the monomer chemical structure. At the high end of the strain ranges achieved, some of the networks exhibited strain hardening behavior. This work develops fundamental relationships between the molecular structure of the phenolic acids, including number and placement of functional groups, and the physical properties of the resulting networks.
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硝酸钙。
DOI：
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发表时间：
1950
期刊：
影响因子：
--
作者：
W. W. Ewing;R. Mikovsky
通讯作者：
R. Mikovsky
DOI：
--
发表时间：
1969
期刊：
影响因子：
--
作者：
R. Cox
通讯作者：
R. Cox
水杨酸：吃水果和蔬菜的又一个理由。
影响因子：
--
作者：
L. Scheier
通讯作者：
L. Scheier
DOI：
10.1002/pol.1984.180221101
发表时间：
1984-11
期刊：
Journal of Polymer Science Part B
影响因子：
--
作者：
J. E. Mark;M. Tang
通讯作者：
J. E. Mark;M. Tang
通过取代苯基链烷酸烯丙酯的闭环复分解合成新型芳香族大内酯
DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
David P. Brown;H. Q. Duong
通讯作者：
H. Q. Duong