PMMA
Poly(methyl methacrylate)
Glass Transition (Tg)
105–110 °C
Melting Point (Tm)
— (amorphous)
Density
1.17–1.20 g/cm³
CAS Number
9011-14-7
Recycling Code
♺ 7
Category
Engineering
Repeat Unit
–[CH₂–C(CH₃)(COOCH₃)]ₙ–
The repeating unit is the smallest structural fragment whose repetition builds the whole chain. Subscripts show the relative share of each unit in copolymers.
Key Properties
Light transmission ~92 % — higher than glass; outstanding weatherability; scratch-prone; brittle with low impact strength.
Applications
Aircraft glazing, light guides, signage, bone cement, dentures.