How does DSC determine crystallinity?
How does DSC determine crystallinity?
Polymer crystallinity can be determined with DSC by quantifying the heat associated with melting (fusion) of the polymer. This heat is reported as Percent Crystallinity by normalizing the observed heat of fusion to that of a 100 % crystalline sample of the same polymer.
What are the main properties of polymers that can be tested using the DSC method?
Differential Scanning Calorimetry (DSC) Testing of Polymers and Plastics
- Melting point / Melting Range.
- Heat Capacity.
- Crystallization.
- Glass transition.
- Identification.
- Thermal stability.
- Decomposition temperature.
- Oxidative Induction Times (OIT) Testing by DSC.
What does DSC graph show?
Differential scanning calorimetry (DSC) is a thermoanalytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature….Differential scanning calorimetry.
| Acronym | DSC |
| Classification | Thermal analysis |
| Other techniques |
|---|
What is crystallization temperature in DSC?
The crystallization temperature is defined as the lowest point of the dip. The latent heat (enthalpy) of crystallization is determined from the area under the curve. Figure 3: Example of a crystallization ‘peak’ in a plot of heat flow against temperature.
What is degree of crystallinity polymer?
The degree of crystallinity of the polymer is defined as the fraction of the sample which is crystalline. It can be either expressed in terms of the mass fraction or the volume fraction.
How does DSC help in materials Characterisation?
The most important effects that can be analyzed by DSC are melting point, melting range and melting behavior. DSC is also used to determine the heat of fusion, glass transition, and oxidation stability.
Why do polymers crystallize?
Polymers can crystallize upon cooling from melting, mechanical stretching or solvent evaporation. Crystallization affects optical, mechanical, thermal and chemical properties of the polymer.
How DSC is helpful in polymer identification?
Differential scanning calorimetry (DSC) is a technique used to investigate the response of polymers to heating. DSC can be used to study the melting of a crystalline polymer or the glass transition. The DSC set-up is composed of a measurement chamber and a computer. Two pans are heated in the measurement chamber.
What are the factors affecting DSC curve?
Factors affecting DSC curve Instrumental factors: These include parameters such as – Furnace heating rate, furnace atmosphere, recording speed, geometry of sample holders, location of sensors, sensitivity of the recording system and material of the sample container.
What does crystallization temperature mean?
1. n. [Well Completions] The temperature at which crystals will appear in a brine solution of a given density as it cools.
What is crystallization temperature?
A reasonable range of temperature to screen and optimize for protein crystallization is 4 to 45 degrees Celsius and some proteins have been crystallized at 60 (glucagon and choriomammotropin) degrees Celsius.
What is the significance of the DSC melting curve?
DSC melting curves contain a lot of information, e.g. about lamella-distribtuion, recrystallization etc. Usually two, repeated DSC masurements are made to erase the crystallization history during sample preparation. It also contains the crysttallization heat . All quantities are temperature dependent.
What does the DSC test tell us about the plastic part?
DSC testing was performed on a small slice taken from the part. The DSC plot, shown in Figure 7, revealed a small glass transition temperature (Tg) at 188°C. The following evidence led to the most likely assignment of the main type of polyamide in the plastic part:
How does the degree of crystallinity affect the properties of polymers?
Perhaps no fundamental property affects the physical properties of a polymer in so general a way as the degree of crystallinity. Differential scanning calorimetry (DSC) provides a rapid method for determining polymer crystallinity based on the heat required to melt the polymer.
What is the polymer thermal scanner (DSC)?
This tool features many powerful techniques for studying polymer thermal properties and provides essential information to the polymer industry and end users of polymer-based products. This paper will provide an overview of DSC.