Biodegradable material requirements

The increasing popularity of biodegradable materials, which are more susceptible to microbial attack, has boosted the demand for preservation. If the product does not already contain ingredients that are themselves preservatives, such as cationic surfactants, acids, or bases, preservatives may need to be added. The required level of preservatives can be related to water availability (AW), which is defined as the ratio between the water vapor pressure over a substance and the water vapor pressure over pure water at the same temperature [17], In general, an A W of below 70% should be targeted to prohibit microorganism growth [18],... 

LDPE), polypropylene (PP), poly(vinyl chloride) (PVC), and polyethylene tere-phthalate (PET) [48], completely new areas of application are preferred in which biodegradability is required for admission, such as applications in the medical field [50, 51]. The reason for this is obvious. When new materials enter the market, they are in competition with aheady established materials. In the case of PUB, due to its temperature stability, a competition with poly(olefin)s arises for all applications in which biodegradabUity is not required by law (Fig. 12). 

Bioreactors Aqueous reactors Most rapid biodegradation Material input requires See above... 

Already in the 1970s, some requirements were formulated for biodegradable materials [159]. If the materials are to be degraded in landfills, they should ideally ... 

In order to better understand the challenges of biodegradable stent development, it is useful to first think about what a stent must endure during its lifetime. Thus an engineering point of view is outhned in this section to distil some of the key material requirements of biodegradable stents. 

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