Title: PROCESS FOR MAKING BIODEGRADABLE AND/OR BIOABSORBABLE POLYMERS
Number/Link: WO2014/004334
Applicant/Assignee: Lubrizol
Publication date: 03-01-2014
“Gist”: Two sets of parameters are given (and claimed) which, when iteratively adjusted, allow to independently modify the mechanical properties and biodegradation rate of a TPU.
Why it is interesting: Many biomedical materials for implants such as screws, bone plates, tissue scaffolds, pins etc need high mechanical properties but also a controlled biodegradation rate which can vary from weeks to years. According to this case the precise control of the degradation rate is not possible with currently available bio-polymers. The invention claims two sets of parameters one which controls the physical properties of a TPU like the molecular weight, harblock content, crystallinity etc, and another set which controls the biodegradation rate like the amount of ‘hydrolyzable units’ in the backbone, hydrophilicity ect. It is claimed that both mechanical properties and degradation rate can be independently controlled by adjusting one or more parameters of each set. In the examples TPUs are prepared from HMDI, 1,4-butane diol and poly(lactide-co-caprolactone) diols where the lactide is the hydrolyzable unit.