Page 344 - Biodegradable Polyesters

322 13 Biodegradable Polyester-Based Blends and Composites

lose their mass over time in the living body are commonly known as absorbable,
resorbable,or bio-absorbable polymers as well as biodegradable polymers.These
biodegradable, polymer-based composites have two major applications at present:
in biomedical and commodity products.
A range of polymer-based composites have been used for medical applications,
comprising preventive medicine, clinical inspections, and operating treatments of
diseases. Among these polymers, a group of polymers are called polymeric bioma-
terials when they are used in direct contact with living cells of human bodies. The
characteristic applications of biomaterials in biomedical field are those used for (i)
disposable products, such as blood bag, syringe, and catheter; (ii) prostheses for
tissue replacements, such as dental implant and body muscles; and (iii) artificial
organs used for temporary or long-lasting support, such as artificial kidney, arti-
ficial heart, and vascular graft. These medical applications, although diverse, are
governed by strict regulations [1].
Biodegradability has emerged as an important feature in material selection and
manufacturing process design. The eco-friendly way to degrade waste material is
biodegradation. Biodegradability describes the process of natural degradation of
compounds present in a material by microorganisms present in the environment
[2]. Green economies and green policies have emerged in the past two decades
and their growth is duly supported by the vision of developing eco-friendly prod-
ucts. This has led to extensive use of biodegradable polymer-based composites in
various large-scale industries. Thus there is a growing need to develop novel recy-
clable and biodegradable products. The manufacturing phases include diminution
of raw materials (mining) and manufacture (machining) of products. The con-
sumption phase comprises use of energy for the maintenance of the structure.
The discarding phase consists of incineration, degradation, and recycling. The
usage of natural-fiber-reinforced thermoplastics [3] reduces the problem associ-
ated with the discarding phase because of their environmental-friendly properties.
Cost analysis and additional manufacturing cost against gain in performance of
biodegradable polyesters [4] concluded that the cost of biodegradable polymers
(hence the composites) is higher than nonbiodegradable ones; however, the differ-
ence in price has significantly narrowed over the past 10 years [5]. In this context,
the commonly used biodegradable polyesters are biopolymers and biodegradable
polyester-based composites, which are being progressively researched in recent
years. This category of composite possesses unique mechanical properties and is
biodegradable in nature. An exhaustive area of different types of polyester com-
posites, their manufacturing, properties, and applications are highlighted in this
chapter.

13.2
Reinforcements in Polymer Composites

Composite materials are synthetic or naturally occurring materials prepared from
two or more materials with considerably different physical or chemical properties