POLYMERS

Epoxy Resin — Melting & Curing

As temperature is ramped, the multi-frequency loss factor ε" shows a series of dipole RelaxationRelaxation은 고무에 일정한 변형률이 가해지면, 변형률을 유지하기 위해 필요한 힘은 일정하지는 않지만 시간에 따라 감소합니다. 이러한 특성을 ‘응력 완화’라고 부릅니다. 응력완화의 원인이 되는 과정은 물리적 또는 화학적 그리고 정상적인 조건 하에, 둘 다 동시에 일어날 수 있습니다. relaxation peaks as the epoxy resin passes through its Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition temperature.

The loss factor then rises rapidly as the epoxy melts, reflecting the dramatically increasing Ionic mobility in the resin. The Ion ViscosityIon viscosity is the reciprocal value of the ion conductivity, which is calculated from the dielectric loss factor.ion viscosity curve is derived from the Ionic mobility component of the loss factor and is a frequency independent parameter related to the viscosity of the polymer before gelation and to rigidity after gelation. The Ion ViscosityIon viscosity is the reciprocal value of the ion conductivity, which is calculated from the dielectric loss factor.ion viscosity initially decreases reflecting the effect of increasing temperature on the dynamic viscosity, of the resin. The initiation of reaction, however, competes with the temperature effect by restricting mobility and results in a clearly defined viscosity rises, reflecting the increasing viscosity and cure state of the material. To illustrate the Degree of CureThe degree of curing describes the conversion achieved during crosslinking reactions (curing). degree of cure, the dielectric cure index may be utilized. (measurement with DEA 288)