Grayscale Digital Light Processing and Post‐Treatment for the Fabrication of 3D‐Printed Polymer Blends
Grayscale Digital Light Processing and Post‐Treatment for the Fabrication of 3D‐Printed Polymer Blends
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DOI：
10.1002/adem.202101543
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发表时间：
2022-01
影响因子：
3.6
通讯作者：
John E. Hergert;A. C. Uzcategui;Archish Muralidharan;Victor Crespo-Cuevas;V. Ferguson;R. McLeod
中科院分区：
文献类型：
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作者：
John E. Hergert;A. C. Uzcategui;Archish Muralidharan;Victor Crespo-Cuevas;V. Ferguson;R. McLeod
具有可编程机械和成分异质性的3D打印聚合物共混物是使用灰度数字光处理通过在打印期间空间调制光强度并用第二单体溶胀所得部件来制造的。橡胶状聚（乙二醇）二丙烯酸酯功能梯度印刷品与丙烯酰胺单体溶胀作为交联密度的函数。在二次聚合之后，形成了具有不同组成和刚度的区域的3D打印功能梯度共混物。用于聚合物转化的确定性模型通知打印条件以与基于两种材料的局部体积分数的预测材料性质相对应。在二次聚合时，在印刷结构内存在两个网络，包括玻璃态和橡胶态区域。印刷品内局部区域的压缩模量范围为76至200 MPa，测量的结构模量与使用有限元分析获得的预测值一致。使用灰度曝光印刷的具有规定局部刚度的晶格结构在压缩时有差异地变形。有利地，由于第二聚合物的引入，消除了由未反应的印刷单体的去除引起的局部尺寸变形。该方法提供了对局部机械性能和高形状精度的预测控制，同时保持了瓮光聚合的简单性。
3D‐printed polymer blends with programmable mechanical and compositional heterogeneity were fabricated using grayscale digital light processing by spatially modulating the intensity of light during printing and swelling the resulting part with a second monomer. A rubbery poly(ethylene glycol) diacrylate functionally graded print is variably swollen with acrylamide monomer as a function of crosslinking density. Following a secondary polymerization, a 3D‐printed functionally graded blend with regions of varying composition and stiffness was formed. A deterministic model for polymer conversion informs printing conditions to correspond with predicted material properties based upon local volume fractions of the two materials. Upon the secondary polymerization, two networks are present within the printed structure including glassy and rubbery regions. The compressive moduli of local regions within prints ranges from 76 to 200 MPa and measured moduli of the structures agree with predicted values acquired using finite element analysis. A lattice structure with prescribed local stiffness printed using grayscale exposures deforms differentially when compressed. Advantageously, local dimensional deformations caused by the removal of the unreacted printing monomer are eliminated due to the introduction of the second polymer. This method provides predictive control over local mechanical properties and high shape precision while maintaining the simplicity of vat photopolymerization.