DSC and STA Thermal Analysis Coming to Parul University MNRDC – Hitachi NEXTA Instruments, Pharmaceutical Polymorphism, and SMA Phase Transitions Explained

Thermal analysis is the family of techniques that measure a material’s properties as a function of temperature. Every material has characteristic thermal events: the temperature at which it melts, the temperature at which it crystallises, the temperature at which it undergoes a phase transformation, the temperature at which it begins to decompose, and the temperature at which its amorphous regions gain molecular mobility glass transition. These events are invisible to SEM, XRD, and AFM they exist in the time temperature domain rather than the spatial domain.

For pharmaceutical development, thermal analysis determines whether a drug molecule exists in the correct polymorph the right crystal structure that gives it the intended solubility and bioavailability. For shape memory alloy research, it precisely measures the martensite to austenite transformation temperature the exact temperature at which the SMA actuates. For battery development, it identifies thermal runaway onset temperatures and decomposition pathways. For polymer processing, it determines the glass transition temperature below which the polymer is brittle and melting point above which it flows. None of these questions can be answered by any of the MNRDC’s existing instruments.

A Differential Scanning Calorimeter places the sample and an inert reference material typically an empty aluminium pan in separate, thermally symmetric positions and heats or cools both at a controlled rate typically 10°C per minute. When the sample undergoes a thermal event melting, crystallisation, glass transition, curing, decomposition, it absorbs or releases heat differently from the reference. The DSC measures this heat flow difference continuously, producing a heat flow vs temperature curve.

Endothermic events heat absorbed appear as peaks below the baseline melting and glass transitions are endothermic. Exothermic events heat released appear as peaks above the baseline crystallisation and curing reactions are exothermic. The area under a peak gives the enthalpy of the transition; the peak position gives the transition temperature; the step in baseline at the glass transition gives the change in heat capacity. This single measurement delivers a complete thermal fingerprint of the material.

Polymorphism the ability of a molecule to exist in multiple crystal structures is one of pharmaceutical science’s most commercially critical phenomena. Different polymorphs of the same drug can have dramatically different solubility, dissolution rate, bioavailability, stability, and patent status. DSC detects polymorphic transitions as characteristic endothermic peaks at specific temperatures unique to each polymorph. Researchers using the MNRDC’s B.Pharm and M.Pharm programmes can directly characterise API polymorphism using DSC a technique central to formulation development, regulatory submissions, and quality control.

Excipient compatibility testing determining whether a drug and its formulation excipients interact unfavourably is another primary pharmaceutical DSC application. When a drug excipient mixture is heated in the DSC, any thermal interaction between them eutectic formation, chemical reaction, physical mixing produces a new peak or shifts the drug’s characteristic melting peak. This is considerably faster than accelerated stability studies and provides mechanistic insight into incompatibilities.

For the MNRDC’s ISRO funded Shape Memory Alloy project , the NEXTA DSC 200 provides a crucial capability: precise measurement of the martensite to austenite transformation temperatures Ms, Mf, As, Af martensite start, martensite finish, austenite start, austenite finish. These four temperatures define the thermal window over which the SMA actuates. For space applications, where the actuation must occur at a specific orbital thermal environment temperature, precise DSC measurement of transformation temperatures and how they shift with processing, composition, and thermal cycling is essential data for mission planning.

The NEXTA STA 200 combines DSC and Thermogravimetric Analysis TGA in a single instrument measuring heat flow AND sample mass change simultaneously as a function of temperature. TGA alone tells you how much mass a sample loses or gains at each temperature from moisture evaporation to organic decomposition to oxidation. DSC alone tells you the thermal events. STA delivers both simultaneously on the same sample in the same run, which is critical because the two measurements inform each other: a mass loss event that coincides with an exothermic DSC peak indicates combustion; one that coincides with an endothermic peak indicates decomposition or evaporation.

For the MNRDC’s Royal Academy of Engineering UK green hydrogen research and for battery materials characterisation broadly, STA provides thermal stability profiles the temperature at which electrolytes decompose, electrodes lose mass, and reactions become exothermic in ways that could cause thermal runaway. These measurements are fundamental to battery safety certification and to optimising electrocatalyst stability for hydrogen production applications.

STA directly characterises the thermal behaviour of the polymer specimens produced on the MNRDC’s Compression Molding Machine – measuring glass transition (DSC), degradation onset (TGA), and char residue (TGA) in a single run. For metal matrix composites produced on the Stir Casting Machine, STA measures oxidation behaviour and identifies decomposition temperatures that define safe operating envelopes. For students in B.Tech Chemical Engineering at Parul University, DSC and STA are core instruments in polymer science and thermodynamics curricula.

The NEXTA series from Hitachi High Tech Analytical Science represents the latest generation of Japanese precision thermal analysis instrumentation. The NEXTA DSC 200 offers high sensitivity, a wide temperature range, fast cooling capability enabling accurate measurement of crystallisation during controlled cooling, and compatibility with atmosphere control nitrogen, argon, or air for testing under different environmental conditions. The NEXTA STA 200 provides simultaneous DSC and TGA measurement with a high precision balance and low baseline noise enabling detection of small mass changes that older instruments would miss.