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--- en:materialdaten:thermodynamische_daten [2024/10/17 17:16] – [Thermodynamic Data] neelest
+++ en:materialdaten:thermodynamische_daten [2026/09/17 09:23] (aktuell) – gelöscht - Externe Bearbeitung (Unbekanntes Datum) 127.0.0.1
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-======Thermodynamic data======
-{{ :materialdaten:rex171_mat_de_002.png?nolink |}}
-==== Specific Heat Capacity ====
-The function curve of the specific heat capacity $c_p$ at ambient pressure for
-amorphous and semi-crystalline thermoplastics is shown in the following figure. In the
-melting range the specific heat capacity follows a virtually linear course and can thus
-be described by a straight-line equation:
-\[c_p(T) = c_{p,0} + c_{p,m}\cdot T\]
-{{ :materialdaten:abb_waermekapazitaet_en.svg?700 |}}
-==== Specific Enthalpy ====
-The specific enthalpy results from the integral of the specific heat capacity $c_p (T)$
-between the limits $T_1$ and $T_2$:
-\[Δh = \int \limits_ {T_1}^{T_2} c_p(T)dT\]
-Thus, one obtains the quantity of heat expressed in terms of the mass unit, which is
-required to increase the temperature of the polymer from $T_1$ to $T_2$. In case of
-amorphous materials, a steeper increase is seen in the temperature if the glass
-transition point $T_g$ is exceeded.
-By contrast, semi-crystalline materials show a
-stepwise increase on account of the phase change. The additional quantity of heat is
-described as the melting enthalpy $∆h_A$. The following figure shows the specific enthalpy as a
-function of temperature.
-With indicating **amorphous thermoplastics** the field for melting enthalpy is not
-editable. In case of **semi-crystalline thermoplastics** the increase in enthalpy $∆h$ is
-formed by an enthalpy increase of the solid material $∆h_F$ and the melting enthalpy
-$∆h_A$ :
-Amorphous thermoplastics: \[∆h=∆h_F\]
-Semi-crystalline thermoplastics: \[∆h=∆h_F+ ∆h_A\]
-{{ :materialdaten:abb_enthalpie_en.svg?700 |}}
-==== Thermal Conductivity ====
-In the case of thermal conductivity, it is necessary to distinguish between steadystate and non-steady-state temperature fields. With steady-state temperature fields
-only the thermal conductivity $λ$ is available as a material value. This is
-temperature-dependent and higher for semi-crystalline materials than for amorphous
-ones.
-\[λ(T) = λ_0 + λ_m \cdot T\]
-$λ_0$ represents the value obtained from the straight line that describes the
-melt range at 0 degrees. The gradient for the thermal conductivity $λ_m$
-can also be negative and must then be entered with a negative sign. The effective
-thermal conductivity of the solid is required for the melting calculation. In order to
-determine this value it is necessary to enter the thermal conductivity of the solid $λ_F$. The melting temperature $T_{k,g}$ must be entered in this mask. In the case
-of semi-crystalline materials this temperature is interpreted as the crystalline melting
-point $T_k$ and in case of amorphous polymers as the glass transition point $T_g$.
-{{ :materialdaten:abb_warmeleitfaehigkeit_en.svg?700 |}}