4D Printing of Smart Polymer Nanocomposites: Integrating Graphene and Acrylate Based Shape Memory Polymers.

Jaydeep Chowdhury,Vijay Kumar Thakur,Premnath Vijay Anirudh,Chidambaram Kannan,Chandrasekaran Karunakaran,Walaa F Alsanie,Arun Tom Mathew,Krzysztof Koziol,Arunachalam S S Balan,Vasudevan Rajmohan

doi:10.3390/polym13213660

Abstract

The ever-increasing demand for materials to have superior properties and satisfy functions in the field of soft robotics and beyond has resulted in the advent of the new field of four-dimensional (4D) printing. The ability of these materials to respond to various stimuli inspires novel applications and opens several research possibilities. In this work, we report on the 4D printing of one such Shape Memory Polymer (SMP) tBA-co-DEGDA (tert-Butyl Acrylate with diethylene glycol diacrylate). The novelty lies in establishing the relationship between the various characteristic properties (tensile stress, surface roughness, recovery time, strain fixity, and glass transition temperature) concerning the fact that the print parameters of the laser pulse frequency and print speed are governed in the micro-stereolithography (Micro SLA) method. It is found that the sample printed with a speed of 90 mm/s and 110 pulses/s possessed the best batch of properties, with shape fixity percentages of about 86.3% and recovery times as low as 6.95 s. The samples built using the optimal parameters are further subjected to the addition of graphene nanoparticles, which further enhances all the mechanical and surface properties. It has been observed that the addition of 0.3 wt.% of graphene nanoparticles provides the best results.

Highlights

Its influence in the medical fields cannot be understated in recent years; for instance, cardio and neurovascular splints and orthopedic braces were manufactured with exact specifications for the human body [2,3]. 4D printing is a paradigm in modern applications and involves the actuation of smart materials, including Shape
There has been an increase in demand for the advanced composite matrix that has improved mechanical properties that can fulfil the performance required in applications
Graphene is used as a cost-effective substitute for carbon nanoparticles, with higher aspect ratios and surface areas leading to enhanced properties in the host matrix [8,9,10]

Summary

Introduction

Di (ethylene glycol) diacrylate (DEGDA), when combined with the monomers of tertiary butyl acrylate, forms the shape memory polymer of tBA-co-DEGDA, which exhibits superior properties attributed to the presence of double bonds and reactivity. It exhibits a prolonged cycle of the shape memory effect, which is as essential as the higher complex and functional structures which are built [4]. It can be effectively used in soft robotics as a material that gives responses to temperature-based stimuli. Graphene is used as a cost-effective substitute for carbon nanoparticles, with higher aspect ratios and surface areas leading to enhanced properties in the host matrix [8,9,10]

Methods

Results

Conclusion