Polymer Chemistry

• Free radical, ionic, coordination
• Rapid molecular weight build-up
• Active center propagation

# Example: Degree of polymerization
def degree_of_polymerization(conversion, functionality):
    """
    Calculate X_n for step-growth.
    conversion: p (0-1)
    functionality: f (functionality)
    """
    return 1 / (1 - conversion)

# Molecular weight distributions
def number_average_mn(degree_polymerization, monomer_mw):
    """M_n = X_n × M_0"""
    return degree_polymerization * monomer_mw

def weight_average_mw(degree_polymerization, monomer_mw, mw_dist):
    """M_w = Σ(N_i × M_i²) / Σ(N_i × M_i)"""
    # Polydispersity index: PDI = M_w/M_n
    return degree_polymerization * monomer_mw * mw_dist

Polymer Properties

• Glass transition temperature (Tg)
• Melting temperature (Tm)
• Crystallinity
• Molecular weight (Mn, Mw)
• Polydispersity index
• Mechanical properties

Important Polymers

• Polyethylene (PE): Packaging
• Polypropylene (PP): Automotive
• Polystyrene (PS): Insulation, foam
• Polyvinyl chloride (PVC): Construction
• Polyethylene terephthalate (PET): Fibers, bottles
• Polytetrafluoroethylene (PTFE): Non-stick