Classification of biodegradable polymers

Biopolymers from natural origins include, from a chemical point of view, six sub-groups  

proteins (e.g., gelatine, casein, wheat gluten, silk and wool) 

lipids (e.g., plant oils including castor oil and animal fats) 

polyesters produced by micro-organism or by plants (e.g., polyhydroxy-alcanoates, poly-3 -hydroxybutyrate) 

polyesters synthesised from bio-derived monomers (polylactic acid) 

---

The report starts with an overview of biodegradable polymers including an examination of the processes of biodegradation, classification of biodegradable polymers including their chemical structure, properties, and processing performance. 

Figure 5.2 Classification of biodegradable polymers, also on the basis of their origin (Av rous and Pollet, 2012).

Figure 6.2 Classification of biodegradable polymers based on their origin. Adapted from [10,18,37,132].

Key words biodegradable polymer, biodegradation, classification of biodegradable polymers, mechanism of biodegradation, testing method, application. 

It is difficult to make a distinct classification of biodegradable polymers. Many authors have classified them according to their origin as natural or synthetic polymers. Both of these are subdivided into different classes based on the main linkages present in their structure. Thus completely biodegradable natural polymer subclasses include polysaccharides, polypeptides, polyesters, lipids, natural rubber and natural composites (wood). Partially biodegradable synthetic polymer subclasses include polyesters, polyur eas, polyurethanes, polyamides, poly( vinyl alcohol) and poly (ethylene glycol). 

Table. 8.2 Classification of Biodegradable polymer following the Heller terms.

Figure 11.6 Classification of biodegradable polymers used in bionanocomposites [87, 88].

A. M. Clarinval and J. Halleux, Classification of Biodegradable Polymers, in Biodegradable Polymersfor Industrial Applications, CRC Florida, USA, 2005. 

Classification of biodegradable polymers 21 Table 1.2 Properties of natural fibres (Drzal et al., 2003)... 

Classification of biodegradable polymers 29 Table 1.4 Comparison of typical biodegradable polymer properties with polyolefins... 

Figure 3. Classification of biodegradable polymers (a) Type I, (b) Type II,

---