​1. Equipment Setup

• Differential Scanning Calorimeter (DSC): Ensure the DSC instrument is properly calibrated and ready for use.
• Dynamic Mechanical Analyzer (DMA): Verify that the DMA instrument is calibrated and operational.
• Tensile Testing Machine: Ensure the tensile testing machine is calibrated and equipped with appropriate grips for specimen testing.
• Heating System: If necessary, prepare a heating system capable of controlling temperature for shape recovery experiments.
• Sample Preparation Equipment: Gather tools for preparing specimens, such as cutting devices and molds.

2. Sample Preparation

• Obtain Shape Memory Polymer (SMP) specimens according to the desired dimensions and shape.
• Optionally, program the SMP specimens into a temporary shape by deforming them at an elevated temperature above their transition temperature (T_trans).
• Cut the programmed specimens into desired shapes for testing.
• Optionally, anneal the specimens to remove residual stresses and ensure uniform properties.

3. Thermal Analysis (DSC)

1. DSC Analysis:
   • Conduct a DSC analysis to characterize the thermal properties of the SMP, including T_trans and enthalpy of phase transitions.
   • Heat the specimen from below its T_trans to above its T_trans at a controlled rate while monitoring heat flow.
   • Determine the T_trans temperatures associated with shape memory effects such as the glass transition temperature (T_g) and melting temperature (T_m).

4. Dynamic Mechanical Analysis (DMA)

1. DMA Analysis:
   • Perform DMA testing to evaluate the viscoelastic behavior and mechanical properties of the SMP.
   • Apply a sinusoidal deformation or stress to the specimen while varying the temperature.
   • Measure storage modulus, loss modulus, and damping as functions of temperature to assess the transition temperatures and mechanical behavior.

5. Shape Recovery Characterization

1. Tensile Testing:
   
   • Conduct tensile testing on programmed SMP specimens to assess shape fixity and shape recovery.
   • Apply tensile load to the programmed specimens at a temperature below T_trans to fix the temporary shape.
   • Heat the specimens above T_trans to initiate shape recovery and measure the recovery strain.
   • Calculate the shape fixity ratio (R_f) and shape recovery ratio (R_r) using the appropriate formulas:

​(a)-(c): programming (short term shape fixity ratio)
(c)-(d): creeping/relaxation (long term shape fixity ratio)
​(d)-(e): recovery (shape recovery ratio)

        2. Visual Inspection:

• Visually inspect the shape recovery process to assess the extent and quality of shape recovery.
• Record any changes in shape and dimensions during the recovery process.

6. Data Analysis

• Analyze the data collected from thermal analysis, DMA, tensile testing, and visual inspection to evaluate the shape memory performance of the SMP.
• Interpret the results to understand the material's shape memory behavior and performance characteristics.

7. Reporting

• Summarize the experimental procedures, results, and analysis in a comprehensive report.
• Include details on sample preparation, testing conditions, data analysis methods, and conclusions drawn from the study.

8. Safety Precautions

• Adhere to safety protocols when handling samples and operating testing equipment.
• Ensure proper ventilation and safety measures are in place, especially when working with heating systems.

This procedure provides a systematic approach to characterize the shape memory performance of shape memory polymers, integrating thermal analysis, mechanical testing, shape recovery experiments, and data analysis. Adjustments may be made based on specific material properties and experimental objectives.

Reference

​Characterization of polymeric shape memory materials