composites 4

Question 1

what is a matrix in composites?

Answer 1

environment or substance in which a thing is developed, or substance between cells or which structures are embedded.

Question 2

what is the function of a polymer matrix?

Answer 2

protects fibre (mechanically and chemically), carries shear stress while fibre takes tensile stress, allows transmission of stress into fibre by shear at matrix/fibre interface

Question 3

what are processing requirements for polymer matrix?

Answer 3

good impregnation (ideally low viscosity), ease of shaping, hopefully quick processing, quality assurance, long pot lifew

Question 4

why are thermosets used as polymer matrices?

Answer 4

fast curing, aromatic backbone so high stiffness and Tg

Question 5

what are some common additives to epoxy resin?

Answer 5

accelerators to increase cure speed
flexibilisers
diluents (lower viscosity)
flame and fire retardants

Question 6

how are thermoplastics processed into matrix?

Answer 6

simple melt/freeze sorta thing

Question 7

what are advantages of using thermosets as matrix?

Answer 7

low processing temp, faster cycle times, better compression strength, better translation of fibre properties, generally more resistant to other solvents

Question 8

what are advantages of using thermoplastics as matrix?

Answer 8

processing is easier to control, recyclability, tougher, more resistant to moisture

Question 9

why is it more difficult to put a fine array of fibres into thermoplastic rather than thermoset?

Answer 9

thermoplastic generally more viscous at their processing temperature than thermosets