Formulae Flashcards
eq for shear stress
τ = F/A
eq for shear rate
Ẏ = v/h = dv/dh
eq for strain in terms of h
dx/h
eq for viscosity
μ = τ/Ẏ
what are the units for toughness?
energy per volume
units for stiffness?
Pa or MPa or GPa
units for ultimate tensile strength?
Pa or MPa or GPa
eq for stress and strain combined
σ = Eε
where σ = stress
E = elastic modulus
ε = strain
eq for E
E = σ/ε
units for E
N/m^2 or Pa or MPa or GPa
eq for strain
ε = ΔL / L_0
where ΔL = change in length of sample
L_0 = initial length
units for strain
NO units or sometimes %
eq for stress using force
σ = force/A_0
where A_0 = cross-sectional area from sample
units for stress
N/m^2 or Pa or MPa or GPa
conversion for MPa
10^6 Pa
conversion for GPa
10^9 Pa
units for shear stress
N/m^2 or Pa
units for shear rate
1/s = s^-1
units for viscosity
Pa/s^-1 = Pa s
converting Pa s to mPa s
1Pa s = 1000 MPa s
eq for Xc
Intensity of the crystalline regions/ (intensity of the crystalline + amorphous regions)
intensity measured from the area under the curves of the PXRD graph
amorphous = broader peaks along the bottom
How do you measure the crystallinity for DSC?
% crystallinity = [ΔHm - ΔHc] / ΔHm°
calculating Tg of a miscible polymer blend
Tg = (Tg)afa + (Tg)bfb
where f is the volume fraction of each polymer (a & b)
OR
1/Tg = Ma/(tg)a + Mb/(Tg)b
where M is the mass fraction of each polymer (a & b)
labelling the topologies/stoichiometries/linkers for porous organic cages
X^m_p Y^n
X and Y are the connectivities of each linker (1&2) e.g. di, tri, tet
m and n are the number of each molecule in the cage
p is the number of double connections
ALWAYS START WITH THE HIGHEST NO. FOR X
eq for G*
T_A / Y_A
where T_A = shear stress
Y_A = shear strain
