Supplier Data - Polyhydroxybutyrate - ( PHB ) Biopolymer ( Goodfellow )

Topics Covered

Background

Chemical Resistance

Optical Activity

Polyhydroxybutyrate ( PHB ) Homopolymers

Key Properties

About Goodfellow

Background

Polyhydroxybutyrate (PHB) and its copolymers with polyhydroxyvalerate (PHV) are melt-processable semi-crystalline thermoplastics made by biological fermentation from renewable carbohydrate feedstocks. Polyhydroxybutyrate (PHB) have been described as “the first example of a true thermoplastic from biotechnology” and are also biodegradeable. Although quite stable under everyday conditions they degrade slowly in the body and when composted or in landfill sites. [The HB monomer unit is a normal constituent of human blood.]

Chemical Resistance

The chemical resistance of Polyhydroxybutyrate (PHB) is somewhat limited as they are attacked by acids and alkalis and dissolve in chlorinated solvents.

Optical Activity

Rather remarkably, Polyhydroxybutyrate (PHB) are optically active polymers with a chiral site in each molecular repeat unit, all of which are in the D- (or R) configuration.

Polyhydroxybutyrate ( PHB ) Homopolymers

Polyhydroxybutyrate (PHB) homopolymer is a stiff and rather brittle polymer of high crystallinity, whose mechanical properties are not unlike those of polystyrene, though it is less brittle and more temperature resistant. Also, its degradation rate is quite high at its normal melt processing temperature. Hence, Polyhydroxybutyrate (PHB) copolymers are preferred for general purposes. It is believed that the most likely area for the application of homopolymer is in the medical/biological fields.

Key Properties

The key properties of Polyhydroxybutyrate - ( PHB ) Biopolymer are tabulated below.

Table 1. Key properties

Chemical Resistance

 

 

 

 

Acids - dilute

Fair

 

Alcohols

Fair

 

Alkalis

Poor

 

Greases and Oils

Good

 

Electrical Properties

 

 

 

 

Dielectric constant @1MHz

3.0

Volume resistivity ( ohm.cm )

1016

Mechanical Properties

 

 

 

Izod impact strength ( J.m-1 )

35-60

Tensile modulus ( GPa )

3.5

Tensile strength ( MPa )

40

Physical Properties

 

 

 

Density ( g.cm-3 )

1.25

Resistance to Ultra-violet

Fair

Thermal Properties

 

 

 

Upper working temperature ( °C )

95

About Goodfellow

Goodfellow supplies metals, ceramics and other materials to meet the research, development and specialist production requirements of science and industry worldwide.

 

 

Source: Goodfellow

 

For more information on this source please visit Goodfellow.

 

Date Added: Mar 4, 2003 | Updated: Jun 11, 2013
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