Considerations for how to choose polymer processing
design complexity: some parts might need to be joined together with adhesives or welding
cost: is it disposable? etc
scale: will it be mass production or personalization?
thermoplastics vs thermosetting
- for thermoplastics: what Tg/Tm do you want?
- for thermosets: use linear “prepolymer”
and “curing”
What are some forms of polymer processing?
Overview of injection molding
Injection molding of thermosets
thermoplastics “set” when they cool
- mold temperature is set to allow full cavity fill while increasing the production rate
thermosets undergo a chemical crosslinking that produces the solid structure
- mold temp will be hotter usually- set to allow full cavity fill while accelerating the chemical reaction to cure
- generally called “Reaction Injection Molding” (RIM)
Overview of Extrusion
Poly(anhydrides)
What are some advantages/disadvantages of polyanhydrides?
Polyanhydride synthesis
Overview of aliphatic vs aromatic polyanhydrides
Poly-trimethylene Carbonate (TMC)
Copolymers of TMC
Copolymers of glycolide with trimethylene carbonate
(TMC), called polyglyconate
* Typically, these are prepared as A-B-A block copolymers in a 2:1 glycolide:TMC ratio, with a glycolide-TMC center block (B) and pure glycolide end blocks (A). These materials have better flexibility than pure PGA and are absorbed in approximately 7 months.
Two examples of PGA-TMC
Flexisurge Adhesion Barrier to prevent fibrous tissue growth across to other organs/tissues
PLA-TMA stent: fully resorbable
Polycarbonate of glycerol
Polycarbonate-esters of Glycerol and
Lactic acid
Poly(carbonate-ester)s based on
Caprolactone and Glycerol
What can you do with a functionalizable biocompatible polycarbonate?
