Quantitative analysis of biodegradable polymers (PLLA & PCL) thermal bonding

A quantitative analysis of the bond strength and microstructure integrity achieved when bonding the biodegradable polymers poly(L-lactide) (PLLA) and poly(e-caprolactone) (PCL) is realized using the response surface methodology (RSM). For the present packaging application the bonding parameters (temperature, pressure, duration) are adapted to optimize the bond strength; The estimated values for bond strength and channel integrity that are predicted by the surface plots are 2.32±0.26 MPa and 33.7±12.9% for PLLA, and 0.81±0.11 MPa and 50.9±5.7% for PCL. These values are in good agreement with the experimentally determined bond strength of 2.00±1.10 MPa (PLLA) & 0.67±0.22 MPa (PCL) and deformation of 31.4±7.0% (PLLA) & 52.9±4.1% (PCL). Microchannels with aspect ratio of 1:12.5 are also fabricated.