BIO-PLASTIC by RAHUL YADAV, PREETI YADAV, V C BRIAN (novels for beginners .txt) 📖

does not require synthetic processing

Uses bacteria/enzymes

Better heat resistance than PLA

Broader range of materials can be used to make PHAs

Polyhydroxybutyrate-co-valerate (PHBVs)

Polyols

Plant oil

Variety of other Bioplastics

Extracted or Used

oil, starch, sugars, lactic acid, fatty acids, proteins, bacteria, fibers

 

Bio-Plastic

Bio Plastic

Classification

 

Polycaprolactones: - It is a biodegradable thermoplastic polymer derived from the chemical synthesis of crude oil. Polycaprolactones has good water, oil,  solvent and chlorine  resistance. It  is mainly in thermoplastic polyurethanes, resins for surface coatings adhesives and synthetic leather and fabrics.

BULK PACKAGING

Packaging is system of preparing goods for transport, distribution storage, retailing and end use. It is means of safe delivery to ultimate consumer in sound condition at economic cost. There are basically three different kind of packages categorized on the basis of use, function, containment of the package.

The first kind of package is unit package, it contain product for one shot is for family requirement, it provides all information related to the product, it also provides aesthetic values and convenience factors to support sales. Intermediate packaging facilitates distribution in the overall marketing system. Bulk, the most important one helps in the complete containment of product or product groups. It facilitates inventory and bulk distribution of package product and also protects them during transportation. To define Bulk Packaging, we can use one of two approaches. The most obvious way is to lay down a basic minimum unit content threshold which is 25 kgs. or 25 liters but this poses certain limitations. The other is to look at the packaging system that what basic function it performs. Using the latter approach, it would be logical to assume that we would want to look at all major applications or packages that are not meant for retail consumption but are only targeted at consumption by manufacturing and processing industries or by organization who are „bulk‟ consumers. In other words, we are looking at packages that contain products which are meant for large-scale or industrial consumption as intermediate inputs for further processing, distribution and re-sale in smaller denominations.

Classification based on basic guidelines there is different bulk packaging systems:

 

Metal packaging (steel drums and barrels, large cans) Rigid plastic packaging (Plastic barrels, IBC‟s, large bottles) Flexible packaging systems (Sacks, woven sacks, FIBC‟s, films for stretch wrapping, shrink wrapping) Paper-based packaging (corrugated fiberboard, multiwall layer sacks, fiber drums) Bag-in-box and bag-in-drum systems Aseptic bulk packaging Wooden packaging (pallets and cases)

 

Our primary focus will be on the rigid plastic packaging and flexible packaging systems because they have to be replaced in recent future by bioplastics. The need of replacement for the petroleum based plastic with bioplastics is just because

Producing conventional plastics consumes 65% more energy than producing Conventional plastic are mostly Plastics last  a  long  time  and  do  huge  damage  to    Therefore,  plastic  is  absolutely unsustainable and bioplastic is more sustainable. Bioplastics saves 30-80% of the greenhouse gas emissions and provide longer shelf-life than normal

 

Bi- Polymer

Bulk packaging systems related with conventional plastics are as follows:-

Intermediate bulk containers (IBC): An Intermediate bulk container is a container used for transport and storage of fluids and bulk materials. The construction of the IBC container and the materials used are chosen depending on the application. They are generally cubic in shape and therefore can transport more material in the same volume than cylindrically shaped containers and far more may be shipped in the same space if packaged in consumer quantities. IBCs range in size but are generally between 700 and 2,000 mm or 1,168 to 1,321mm in height. IBCs may ship and store Bulk chemicals including hazardous materials if the IBC is proven suitable. The plastic used in the manufacturing of IBC‟s are basically polyethylene, polypropylene these are plastics are used because they have lower impact strength, high tensile strength, High compressive strength, excellent dielectric properties, resists to alkalis and acids, resists stress cracking, retains stiffness, low moisture absorption, non- toxic, non-staining, easily fabricated, and high heat resistance.

of

Gas barrier properties: In most packaging applications the gas mixture inside the package consists of carbon dioxide, oxygen and nitrogen or combinations. Biobased materials have quite same oxygen permeability that of conventional mineral-oil-based materials and it is possible to select from a range of barriers among the present biobased materials. The conventional approach to introduce high-barrier films for packaging of food is to use multi-layers of different films in order to obtain the required properties. A laminate that is often used in packaging consists of an layer of EVOH or PA6 combined with LDPE for mechanical strength and the excellent sealing properties. A similar multi-layer approach for biobased materials may be used to produce materials with the required properties. Starch-based materials could provide cheap alternatives to presently available gas barrier materials like EVOH and PA6 and  an equivalent biobased laminate would be an outer- layer of plasticized chitosan, a protein or starch-derived film combined with PLA or PHA. PLA and PHA will protect the moisture-sensitive-gas-barrier made of polysaccharide and protein. Developments have made it possible to improve water vapour and gas properties of biobased materials many-fold by using plasma deposition of glass- like SiOx coatings on biobased materials or the production of nano-composites out of a natural polymer.

In general, the oxygen and other gases permeability of a specific material are closely interrelated, petroleum based polymers have a fixed ratio between the oxygen and carbon dioxide permeabilities. This relation is also observed for biobased materials. However, for some biobased materials,like PLA and starch, the permeability of carbon dioxide in comparison to oxygen is much higher than for petroleum based plastics.

 

Barrier

Gas barriers, humidity and microbial growth
As many of these biobased materials are hydrophilic in nature therefore their gas barrier properties are very much dependent on the humidity conditions for the measurements and its gas permeability may increase many times with when increase in humidity. Same is the phenomenon with conventional polymers. Gas barriers based on PLA and PHA is not expected to be more dependent on humidity. According to the study microbial contamination levels of packages made from conventional and biobased materials are relatively below the standard of 1 organism/cm2. A microbial study of cellulose triacetate, a type of bioplastic shows that after years of storage under ambient conditions mostly Pseudomonas bacteria is found in the film. Different tests for fungal growth (ASTM G21-96, G22-76, G21-70) has been conducted on the bioplastics, after many years of storage it was found that a low growth of selected food related fungi like Penicillium ocured in the same.

 

Bioplastics

Starch based plastics: - Starch the storage polysaccharide of cereals, legumes and tubers is a renewable and widely available raw material for bioplastics. Flexibiliser and plasticizer such as sorbitol and glycerin are added so that starch can also be processed. As a packaging material starch alone does not form films with adequate and required s mechanical properties of high percentage elongation, tensile and flexural strength unless it is treated by either plasticization, blending with other materials, genetic or chemical modification or combinations of different approaches. For which corn is the primary source of starch, although considerable amounts of starch are produced from potato wheat and rice starch.

Bioplastics produced from classical chemical synthesis from biobased monomers: - Using classical chemical synthesis for the production of polymer gives a wide spectrum of possible “bio-polyesters”. Polylactic acid is the polymer with the highest potential for a commercial production of renewable packaging materials. However, a wide range of other bio polyesters can be made. Theoretically, all the conventional packaging materials derived from mineral oil today in coming future can be produced from renewable monomers gained by fermentation. Today, this approach is not feasible due to the cost of the production of the monomers has economical constraint.

Polylactic Acid (PLA) plastics: - Polylactic acid, PLA is a biodegradable, thermoplastic, aliphatic polyester derived from lactic acid. The lactic acid source of PLA is itself produced from the fermentation of agricultural by-products such as corn-starch or other starch-rich substances like maize, sugar or wheat. PLA has high potential for packaging applications. The properties of the PLA material are highly related to the ratio between the two mesoforms of the lactic acid monomer. Using 100% L-PLA results in a material with a very high melting point and high crystallinity. A 90%/10% D/L co-polymers gives a material which can be polymerized in the melt, oriented above its Tg and is easily processable showing very high potential of meeting the requirements of bulk packaging. PLA may be formed into blown films, injection moulded objects and