Structural Evidence That the Polymerization Rate Dictates Order and Intrinsic Strain Generation in Photocured Methacrylate Biomedical Polymers
Structural Evidence That the Polymerization Rate Dictates Order and Intrinsic Strain Generation in Photocured Methacrylate Biomedical Polymers
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聚合速率决定光固化甲基丙烯酸酯生物医用聚合物的有序和固有应变生成的结构证据
DOI：
10.1021/acs.macromol.9b00133
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发表时间：
2019
期刊：
影响因子：
5.5
通讯作者：
Sirovica S
中科院分区：
文献类型：
--
作者：
Sirovica S
利用中子和原位同步x射线散射和同步傅里叶变换近红外光谱研究了反应速率对光活化二甲基丙烯酸酯生物医用树脂聚合物结构演变的影响。先前的研究已经将反应基团转化的程度与机械性能联系起来，但聚合速率对所得聚合物结构的影响尚不清楚。在这里，我们证明了这些材料的功能端基的中程结构顺序取决于反应速率。与较慢的聚合体系相比，加速聚合增加了甲基丙烯酸酯端基的相关长度，但降低了每转换乙烯基键的中等范围结构顺序。在更快的聚合速率下，反应端基原子的构象可以在自减速开始时固定到聚合物结构中，存储残余应变。中子散射证实，所观察到的结构差异可以在更长的尺度上重现。尽管反应基团转化的最终程度相似，但在以较慢速度聚合的体系中，这种效应并不突出。结果表明，目前对这些材料的解释，从转换推断机械性能，可能是不完整的。加速聚合可以引入结构差异，这将决定残余应变，并可能最终解释使用传统技术预测这些材料力学行为模型中的差异。
The influence of reaction rate on the evolving polymer structure of photo-activated dimethacrylate biomedical resins was investigated using neutron and in situ synchrotron X-ray scattering with simultaneous Fourier-transform-near-infrared spectroscopy. Previous studies have correlated the degree of reactive group conversion with mechanical properties, but the impact of polymerization rate on the resultant polymer structure is unknown. Here, we demonstrate that the medium-range structural order at the functional end groups of these materials is dependent on the reaction rate. Accelerating polymerization increases correlation lengths in the methacrylate end groups but reduces the medium-range structural order per converted vinyl bond when compared with more slowly polymerized systems. At faster rates of polymerization, the conformation of atoms at the reacting end group can become fixed into the polymer structure at the onset of autodeceleration, storing residual strain. Neutron scattering confirms that the structural differences observed are reproduced at longer length scales. This effect is not as prominent in systems polymerized at slower rates despite similar final degrees of reactive group conversion. Results suggest that current interpretations of these materials, which extrapolate mechanical properties from conversion, may be incomplete. Accelerating polymerization can introduce structural differences, which will dictate residual strain and may ultimately explain the discrepancies in the predictive modeling of the mechanical behavior of these materials using conventional techniques.
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影响因子：
1.9
作者：
Asmussen, E;Peutzfeldt, A
通讯作者：
Peutzfeldt, A
第 5 章 – 亚克力
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
B. Darvell
通讯作者：
B. Darvell
影响因子：
5
作者：
Feng, Li;Carvalho, Ricardo;Suh, Byoung I.
通讯作者：
Suh, Byoung I.
影响因子：
5
作者：
Lovell, LG;Lu, H;Bowman, CN
通讯作者：
Bowman, CN
影响因子：
3.4
作者：
Sarkar S;Baker PJ;Chan EP;Lin-Gibson S;Chiang MYM
通讯作者：
Chiang MYM