Page 35 - תקצירי תזות הנדסה ירוקה 2025

Development of 3D-Printed Polymer Materials for Extreme Conditions
Eva Benhamou; benhamou.eva1@gmail.com
Prof. Ariela Burg1, Dr. Inna Levitsky1, Dr. Yuval Vidavsky2
1SCE - Shamoon College of Engineering, Be’er-Sheva
2Soreq Nuclear Research Center, Space Environment Department, Yavne
Additive manufacturing, also known as ‘3D printing’, has transformed the aerospace industry by allowing the production of mission-specific components on demand, minimizing the need for continuous resupply, and reducing production times. However, the harsh environment of space, characterized by extreme conditions, such as atomic oxygen, high vacuum, and fluctuating temperatures, demands the development of robust materials that can withstand such challenges. This study explores the development of a 3D-printed bismaleimide-triazine )BT( resin, a blend of bismaleimide )BMI( and cyanate ester )CE(, based on thermosets tailored for space applications. BMI was selected due to its UV-reactive maleimide groups, which enable photopolymerization and make it compatible with digital light processing )DLP( printing, while CE was chosen for its ability to enhance the mechanical and thermal properties of the material. The optimal formulation identified was BT50, a 50:50 weight ratio of BMI and CE. This formulation enabled efficient 3D printing and maintained two glass transition temperatures, 50°C for the BMI component and 260°C for the CE component. Diallyl bisphenol A )DBA( was added to boost mechanical properties, raising the storage modulus at 50°C from 1400 MPa to 1800 MPa and slightly increasing the glass transition temperatures to 70°C and 280°C.
While the addition of carbon fibers, known for improving mechanical properties, was expected to significantly enhance the material’s performance, the results showed no substantial improvement in terms of glass transition temperature, storage modulus, or flexural modulus, suggesting limited interaction between the carbon fibers and the BMI/CE matrix. Further modifications involved the introduction of polyhedral oligomeric silsesquioxane )POSS(, specifically mono-acryloxypropyl isobutyl POSS and octa-acryloxypropyl POSS. The acrylated group attached to the POSS cage enabled better integration into the BMI/CE matrix, although solubility issues arose with mono- acryloxypropyl isobutyl POSS, due to its powdered form and single acrylate group. The adoption of octa-acryloxypropyl POSS, which contains eight acrylate groups, while more soluble, resulted in a decrease in the storage modulus. Despite these solubility challenges, mono-acryloxypropyl isobutyl POSS was ultimately chosen to maintain a balance in mechanical properties. Outgassing tests, conducted according to ASTM E-595 standards, revealed that all the formulations, except the one containing 10% POSS, passed with the 10% POSS formulation exhibiting excessive volatility, due to solubility challenges.
One of the key findings of this research was the impact of POSS on resistance to atomic oxygen )AO(, a highly erosive agent in low Earth orbit )LEO(. POSS was shown to significantly enhance resistance to AO by forming a protective SiO2 layer that mitigates surface degradation. However, no significant
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