Type Differential Scanning Calorimeter for Polymer Material

Polymer Material Types and Differential Scanning Calorimeter (DSC) Selection and Testing Guidelines

Differential Scanning Calorimetry (DSC) is a core tool for studying the thermal properties of polymer materials, and the functional requirements of DSC vary significantly by polymer type (e.g., thermoplastics, thermosets, elastomers). The following is a detailed explanation of DSC selection and testing for polymer material types:

I. Polymer Material Classification and DSC Testing Highlights

Polymer type

Typical materials

DSC test focus

Thermoplastics

PE, PP, PET, PC

Melting temperature (Tm), crystallinity, glass transition temperature (Tg)

Thermosetting resins

Epoxy resins, phenolic resins

Curing reaction exothermic peak (curing temperature, reaction enthalpy), thermal decomposition temperature

Elastomer

Natural rubber, silicone rubber

Glass transition (Tg), low temperature brittleness point, cross-linking reaction analysis

Blends/Composites

PP/EPDM, PC/ABS

Multiphase melt peak separation, compatibility analysis (judged by Tg shift)

Biodegradable materials

PLA, PHA

Melt-crystallization behavior, thermal stability (oxidation induction time OIT)

II. DSC selection suggestions for different polymer types

Polymer type

Recommended DSC configuration

Key Parameter Requirements

Thermoplastic

- Basic DSC (temperature range: -50℃~400℃)

- Sensitivity: 1μW

- Standard aluminum crucible

Adjustable heating rate (1~20℃/min), support melt peak integration (crystallinity calculation)

Thermosetting resin

- High sensitivity DSC (0.2μW)

- High-pressure sealed crucible (anti-volatilization)

- Fast temperature rise (50°C/min)

Detection of weak exothermic peaks (curing reaction), support for dynamic ramp-up programs (simulation of actual curing conditions)

Elastomer

- Liquid nitrogen cooled DSC (-180°C~400°C)

- Modulated DSC (MDSC)

Low temperature Tg detection (e.g. Tg ≈ -60°C for rubber), separation of reversible/irreversible heat flow (elimination of stress relaxation interference)

Blends/Composites

- High resolution DSC (0.1μW)

- Multi-stage programmed temperature rise

Multi-peak separation capability (e.g., melt bimodal peaks for PP/EPDM), support for specific heat capacity determination (to determine compatibility)

Biodegradable materials

- Oxidation Induction Module (OIT)

- Atmosphere control (O₂/N₂ switching)

Oxidation stability test (OIT value), pyrolysis analysis (e.g. Td≈250°C for PLA)

III. Typical Test Flow and Data Analysis

Case 1: Thermoplastic (PP) melting and crystallization analysis

1. 

Sample preparation: take 5mg PP particles, press piece sealed in aluminum crucible.

2. 

Test procedure:

First round of heating: 30°C → 220°C (10°C/min) to eliminate thermal history.

Cooling down: 220°C → 30°C (10°C/min), record crystallization peaks.

Second round of warming: 30°C → 220°C (10°C/min), record melting peaks.

3. 

Data output:

Melting temperature (Tm): ~160°C (peak temperature).

Crystallinity (Xc): Xc = (ΔHm/ΔH0) × 100% (ΔH0 = 209 J/g, 100% crystalline PP).

Case 2: Analysis of epoxy curing reactions

1. 

Sample preparation: liquid epoxy resin mixed with curing agent and sealed in a high pressure crucible.

2. 

Test procedure:

Constant temperature mode: 25°C→150°C (10°C/min), monitoring the exothermic peak.

3. 

Data output:

Curing onset temperature (Tonset): approx. 80°C.

Enthalpy of reaction (ΔH): total heat (J/g) calculated by integrating the exothermic peak.