Frequently Asked Questions

Biopolymer is a short-hand term which describes a group of plastics which are either biogedrabale or bio-based or both. In more detail, these groups are:
1. Bio-based and biodegradable (under composting conditions)
2. Petroleum-based and biodegradable (under composting conditions)
3. Bio-based and durable (i.e. water and solvent resistant)
Vestamid® Terra is bio-based and durable, thus not biodegradable

 

Officially a final product or plastic to be called bio-based must contain at least 20% renewable carbon content. This renewable carbon content is derived from plant or organic matter such as specially cultivated energy crops. Since plants use CO2 during growth the carbon is fixed from the air and this carbon can be considered renewably sourced. Plants used as a feedstock for chemicals and plastics are typically called biomass.

 

The bio-based carbon content is measured using the radioactive decay properties of the C14 isotope, so-called radiocarbon dating. Described in detail under the ASTM 6866, plant-based carbon is new, fixed from the atmosphere in the last months to years, whereas fossil-based carbon is old, fixed hundreds to millions of years ago. The C14 isotope is naturally formed in the atmosphere and present is a defined concentration. Upon plant fixation and subsequent use it gradually decays at a constant rate. Bio-based materials will thus have a significantly higher C14 content than fossil-based materials. The values are given in weight percent.

 

Yes, in fact the ASTM6866 (2008), DIN10694 (1996) and CEN15932 (2010) all different testing methods and institutional systems classifying products and plastics using radiocarbon dating. In Europe, the DIN method is predominate, in the USA, the ASTM method (a part of the Biopreferred program) is preferred and in Japan, the JORA method is commonly used. The final product needs more than 20% bio-content to be classified as a bio-based polymer. Only is Japan is 30% needed to fulfill the classification.

 

No, the bio-based polyamides products from Evonik are classified as durable and express an excellent resistance to water, chemicals and other solvents. In many applications this is desired.

 

Vestamid® Terra is a family of bio-based long-chain AABB polyamide (more commonly known as nylon). Long chain means the average carbon chain length is more than 6. AABB means it is a two component (monomer) system produced from a diacid and a diamine. There are three products currently in the portfolio: PA610, PA1010 and PA1012.

 

The biomass source is castor bean, Ricinus Communis. The monomers used in the polymerization are partially or completely sourced from castor oil.

 

No, while Vestamid® Terra is based on castor oil as a major part of its feedstock, it does not negatively affect the supply of food crops. There are several key reasons:
1. Castor bean not part of the food chain
2. Castor bean is grown in none-competing areas (typically arid)
3. Castor bean is a very small crop and bio-based polyamides are currently in niche markets, meaning the arable-land used is only a fraction of a percent
4. Worldwide sufficient quantities of food and fodder are produced, the problems lie more in distribution

 

No, typically the castor bean is grown in arid to semi-arid regions (primarily India) and has been so for decades if not centuries. These regions can support a drastic increase in productivity and cultivation without any noticeable effects. Lastly, rain-forest areas are not needed for expansion.

 

There are some studies and research work into genetically modifying castor bean to improve yields or draught resistance, yet has not been implemented on a broad scale. Nearly all commercially available castor oil is thus GMO-free.

 

The proverb "Terra" after Vestamid® denoted a bio-based content above 20%, this is especially relevant for compounds using inorganic or non-based-based additives. The following letter stands for the monomer used:
H: C6-diamine, hexamethylene diamine (fossil based)
S: C10-diacid, sebacic acid (bio-based)
D (starting position): C10-diamine, decamethylene diamine (bio-based)
D (second position): C12-diacid, dodecanedioic aicd (fossil based)
The following two numbers represent the viscosity and the final two are internal.

 

In the world of long-chain polyamides, viscosity is measured in a solution of m-cresol and not in sulphuric acid as commonly done with the short-chain polyamides. Viscosity is a display of how fluid the polymer is when melted.
Low viscosity grade (120-160 cm³/g) are ideal for small injection molded parts
Medium viscosity grades (160 - 200 cm³/g) are ideal for structural injection molded part as well as foil and films
High viscosity grades (200 - 230 cm³/g) are ideal for extrusion parts, like tubes and pipes.
All types from low to high as well as specially required grades are possible.

 

Commodity plastics are high volume plastics with properties good enough to serve the purpose, usually in a one-time use application, like packaging. These plastics are very price sensitive. Engineering plastics are mid-to-high volume with increased properties to serve slightly more demanding applications, usually in longer lasting areas, like casings in electronic equipment. These plastics can be price sensitive. High performance plastics are low-to-mid volume with superior properties selected to perform a specific task, usually in highly demanding areas, like safety relevant brake tubing systems. These plastics are property driven and less price driven. Vestamid® Terra HS classified as engineering, whereas Terra DS and DD are high-performance.

 

In theory yes, any thermoplastic can be recycled. However, since the application fields are broad and require specific compound solutions, the volumes are too small to warrant a collection and recycling scheme. Naturally, in the production processes, surplus material like cuttings can be re-granulated and recycled.

 

LCA stands for life-cycle-assessment which measures all the environmental impacts of a product from the raw material acquisition through the conversion processes to the use-phase and finally the end-of-life disposal. The calculations follow the ISO14040 standard. Alone an LCA is meaningless; it is designed to reveal differences in comparable processes or products.

 

Vestamid® Terra is sold as a polymer pellet and can be used for a wide variant of applications. Evonik has selected to conduct a detailed LCA for the product, known as cradle-to-factory gate. This means, to the point of sale. This data is typically supplied to the customer, who will use the data further to complete their unique LCA of the final product.

 

Yes. Following the comparison between Vestamid® Terra and typical short or long-chain polyamides there is a sizable reduction in CO2eq. In fact compared to PA6, the PA1010 emits less than half the carbon dioxide equivalent.

 

In Shanghai, China. The location was chosen to lower the transportation costs and distances of the monomers, since the bio-based feedstock's come from and are produced in Asia. Many of the final compounds are manufactured in Marl, Germany.

 

In plastics, a compound is a neat polymer mixed with all the necessary additives and ingredients to match the technical and processing requirements of the desired application. Additives can be anything from process and climatic stabilizers to plasticizers or modification components to reinforcement material and coloring.

 

Neat and compounded product is sold in either 25 kg vacuum sealed bags or octobins (500 - 1500 kg) as either dry-grind or underwater pelletized granules. Masterbatch based on polyamides is recommended, as unless specifically agreed upon, natural color and black are the only colors available. Finely ground powder material with varying particle distribution is also available. They are marketed under Vestosint® Terra. While detailed knowledge on fiber and foils processing is available, Evonik is not a fiber or film manufacturer with Vestamid® Terra.

 

Long-chain bio-based polyamides are not a commodity, but are designed to meet a specific technical requirement in specific application fields. Please contact your regional sales representative for further information. more