Polyester-based biodegradable fibre

Fibrous fillers for biomedical PLA-based FRPs include carbon and inorganic fibres [406], PLLA (i.e. self-reinforcement) [407,408], poly(p-dioxane) fibre [409], chitin [410], biodegradable fibre (e.g. bioactive glass, chitosan fibre, polyester amides) [411], hydroxyapatite fibre [412], hydroxyapatite whiskers [413], halloysite (Al2Si205(0H)4) nanotubes [414] and the fibre from different tissue types of Picea sitchensis [415],... 

In any case, biodegradable fibres based on polyesters while investigated and developed by researchers, should be considered seriously by industry and consumers. A knowledge concerning the properties and new techniques of production of the fibres should bring new ideas for applications of these materials followed by development of production technology. 

In contrast to specifying to suppliers what chemicals or materials are restricted, it is useful to specify exactly what chemicals and materials are desired. Once a material or chemical is well characterized, and it is considered benign with respect to human and environmental health, it can be added to a preferred or positive list (i.e., P-list). For example, a textile manufacturer may source certified organic cotton, or polyester made with antimony-free catalysts, to develop a product line based on these fibres. Or a cleaning product formulator may seek bio-based solvents or rapidly biodegradable surfactants consistent with their product development objectives. 

Biological CLR refers to fibres that can be safely composted at end of fife to return nutrients to the soil. Technical CLR refers to the synthetic products that are not biodegradable. In textiles, this is frequently the synthetic polymer-based fibres such as polyester, acrylic and nylon. Blending of the two kinds of streams is referred to by McDonough and Braungart (2002) as a monstrous hybrid , meaning that the two kinds of waste streams cannot be effectively separated for ease of recycling. In the apparel context, monstrous hybrids abound in the form of cotton/polyester, or viscose/polyester, or cotton and spandex blends. 

Natural polymers such as starch and protein are potential alternatives to petroleum-based polymers for a number of applications. Unfortunately, their high solubility in water limit their use for water sensitive applications. To solve this problem thermoplastic starches have been laminated using water-resistant, biodegradable polymers. For example, polylactic acid and P(3HB-co-3HV) were utilised as the outer layers of the stratified polyester/PWS (plasticized wheat starch)/polyester film strucmre in order to improve the mechanical properties and water resistance of PWS which made it useful for food packaging and disposable articles [65]. Moreover, improved physic-chemical interactions between P(3HB-CO-3HV) and wheat straw fibres were achieved with high temperature treatment. It resulted in increased P(3HB-co-3HV) crystallization, increased Young s moduli and lowered values of stress and strain to break than the neat matrix of P(3HB-co-3HV). There was no difference in the biodegradation rate of the polymer [66]. 

Polylactic acid (PLA), the structure of which is shown in Figure 7.10, is a polyester fibre in which there has been recent interest because of its environmental credentials. PLA may be derived from renewable resources, such as cornstarch, and it is biodegradable. PLA may be coloured using certain disperse dyes, although the dyes do not exhaust as well as on PET, mainly because of its aliphatic character. Acrylic fibres are synthetic fibres based essentially on the addition polymer polyacrylonitrile, the essential structure of which is illustrated in Figure 7.11. However, most acrylic fibres are rather more complex and contain within their structure anionic groups, most commonly sulfonate (-SOs ), but also carboxylate (-CO2 ) groups either as a result of the incorporation of co-polymerised monomers in... 

---