# Physical, Thermal, and Mechanical Characterization of PMMA Foils Fabricated by Solution Casting
## 5 Conclusions  
In this work, the effect of two different concentrations of solution of toluene as the ratio of (S/L) was used in the preparation of solution-casting PMMA foils. Characterization techniques such as DSC for the detection of the glass transition in the PMMA samples, microscopy to observe the surface images, a DMA test to measure mechanical properties, and FTIR spectroscopy for detecting structural changes were employed in combination. Both the thermal and mechanical properties of the as-prepared PMMA foils are strongly influenced by the solvents used for the preparation due to their polarity and capability of forming H bonds with the polymer. The reference sample of commercial PMMA was tested to compare the properties of as-prepared PMMA foils. In particular, the samples prepared with toluene as solvents show a glass transition temperature of 16-20 \({}^{\circ}\)C below the bulk commercial PMMA sample. Similarly, the prepared sample shows lower storage and loss modulus in comparison to bulk samples. The spectroscopic analysis provided a comprehensive analysis of structural changes in commercial and as-prepared PMMA samples with the response from the solute powder and solvents toluene. The polymer network structure arises from different hydrogen bonding with chain rigidity in the samples. The polymer chain distortion caused the weakening of the samples prepared from the toluene solution. This behavior is reflected in the tensile test of PMMA samples, as it shows a weaker response in comparison to bulk samples. However, a significant shape  
Figure 9: Shape recovery (%) for commercial PMMA, fabricated 1 and 2 as the function of number cycles.  
memory effect is observed for the solution-cast PMMA films that matches quite well with the commercial sample. The solution cast method allows for tuning the glass transition temperature of polymer foil that could easily integrate with the NiTi alloy phase transition temperature for the fabrication of a suitable composite structure. Integrating both structures will open the flexibility in bistable actuators in composite structures as a function of thermal cycles.  
Conceptualization, S.S. and D.V.; methodology, B.S. and O.T.; formal analysis, B.S.; investigation, O.T. and M.S.; resources, O.T.; data curation, S.S.; writing--original draft preparation, S.S.; writing--review and editing, S.S.; supervision, S.S.; project administration, S.S.; funding acquisition, I.S. All authors have read and agreed to the published version of the manuscript.  
The current study was supported by the Czech Science Foundation under project no. 22-14387] and by Operational Program Research, Development, and Education financed by the European Structural and Investment Funds and the Czech Ministry of Education, Youth, and Sports (Project No. SOLID21--CZ.02.1.01/0.0/0.0/16_019/0000760).  
Not applicable.  
Data availability Statement: Data will be available at the request of readers.  
The first and second authors are thankful to [PERSON] for fruitful discussion on this topic.  
The authors declare no conflict of interest.