import matplotlib.pyplot as plt
import numpy as np

def flory_schulz(x, A, B, Gamma, sigma):
    return A*(1-(1+sigma**2*Gamma*x)**(-1/sigma**2))+B

x = np.logspace(-2, 2, num=200)

y1 = flory_schulz(x, 1, 0, 1, 1)
plt.semilogx(x, y1, 'b-')
plt.xlabel(r'$\Delta t$')
plt.ylabel(r'$D(\Delta t)$')
plt.show()