Biodegradable polymers starch

Since starch is biodegradable, it has found use as filler in polymers, such as extruded films applied to paperboard for use in packaging.295,296 The starch is incorporated in granular form,297 as an octenylsuccinate derivative298 and in other forms. Starch-based blown films are prepared from starch-poly(ethylene-co-acrylic acid) formulations.299... 

During the same period, commercialization of thermoplastic starch polymer blends was pursued by Novamont, a division of the Ferruzzi Group of Italy.162-172 Their products, marketed under the trade name Mater-Bi, are typically comprised of at least 60% starch or natural additive and hydrophilic, biodegradable synthetic polymers.64,165 It is stated that these blends form interpenetrated or semi-interpenetrated structures at the molecular level. Properties of typical commercial formulations have properties similar to those in the range of low- and high-density PE. Blends of Mater-Bi products with biodegradable polyesters have been claimed for use as water impervious films.173... 

New types of renewable feedstock such as palm oil for manufacture of starch-based biodegradable polymers. 

Starch based biodegradable polymers (including modified starch blends)... 

The most relevant achievements in this sector are related to thermoplastic starch polymers resulting from the processing of native starch by chemical, thermal and mechanical means, and to its complexation to other co-polymers. The resulting materials show properties ranging from the flexibility of polyethylene to the rigidity of polystyrene, and can be soluble or insoluble in water as well as insensitive to humidity. Such properties explain the leading position of starch-based materials in the biodegradable polymer field. 

Other leading starch-based biodegradable polymer manufacturers are Biotec and BIOP Biopolymers. 

In terms of biodegradable polymers, PLA is finding growing use for manufacture of thermoformed articles such as single-use disposable cups and trays, particularly for outdoor events. Starch-based biodegradable polymers can also be thermoformed for production of trays and containers for packaging fresh food and convenience food. 

Excluding loose-fill packaging, which is a relatively more mature sector for starch-based biodegradable polymers, global market tonnage in 2005 is 71,700 tonnes and the compound annual growth rate for the period 2005-2010 is projected to be 20.3%. 

Some examples of new applications development for starch-based biodegradable polymers are outlined below. 

Starch-based biodegradable polymers also have a better environmental image than synthetic biopolymers as they are based on sustainable resources, which open up marketing opportunities for brand owners who wish to promote their products as being packaged in materials based on sustainable resources. 

Table 5.1 shows global consumption of starch-based biodegradable polymers by major world region for the years 2000, 2005 and 2010. 

The major world suppliers of starch-based biodegradable polymers are described below. 

Under the Mater-Bi trademark, Novamont produces different classes of starch-based biodegradable materials and blends of starch with synthetic polymers. Each class is available in several grades to meet the needs of specific applications. Classes include grades for film and sheet extrusion, injection moulding and foams. 

Loose-fill packaging was one of the first successful areas of application for starch-based biodegradable polymers. Loose-fill starch-based foam is used for packaging consumer products as an alternative to polystyrene and polyethylene. While, biodegradable plastics have made some inroads into these markets, the future prospects for their growth in loose-fill are not so exciting as they are in some other areas of packaging. 

Starch-based biodegradable polymers will continue to experience good growth in these applications over the next five years. 

Nvyro was established to produce cassava (tapioca) starch based packaging solutions. Tapioca is one of the cheapest sources of raw materials for manufacture of starch based biodegradable polymers. 

This article provides a review of thermoplastic starch polymers [unlike polymers with added granular starch] including an introduction to biodegradable polymers and thermoplastic starch polymers a review of thermoplastic starch polymer development a review of reactive modification of thermoplastic starch, examining the structure-property relationships of thermoplastic starch and a review of commercial thermoplastic starch polymer applications. 

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