Rebirth of Biobased Polymer Development

1
Rebirth of Bio-based Polymer Development

• Dr. Shelby F. Thames
• The University of Southern Mississippi

2
Applications

• Coatings
• Fibers
• Plastics
• Adhesives
• Cosmetics
• Oil Industry
• Paper
• Textiles/clothing
• Water treatment
• Biomedical
• Pharmaceutical
• Automotive
• Rubber

3
Polymers

• Polymers are broadly classified into
• Synthetic
• Natural
• Synthetic polymers are obtained via
  polymerization of petroleum-based raw materials
  through engineered industrial processes using
  catalysts and heat

4
Synthetic Polymers

• Polyethylene
• Polypropylene
• Polytetrafluoroethylene (Teflon)
• Polyvinylchloride
• Polyvinylidenechloride
• Polystyrene
• Polyvinylacetate
• Polymethylmethacrylate (Plexiglas)
• Polyacrylonitrile

• Polybutadiene
• Polyisoprene
• Polycarbonate
• Polyester
• Polyamide (nylons)
• Polyurethane
• Polyimide
• Polyureas
• Polysiloxanes
• Polysilanes
• Polyethers

5
Natural Polymers

• Natural polymeric materials have been used
  throughout history for clothing decoration
  shelter tools weapons and writing materials
• Examples of natural polymers
• Starch
• Cellulose (wood)
• Protein
• Hair
• Silk
• DNA and RNA
• Horn
• Rubber

6
Chronological Development

• Natural resins From early history
• Modified phenolic 1910
• Nitrocellulose 1920
• Air-drying oil-modified polyesters 1927
• Urea-formaldehyde polymers 1929
• Chlorinated rubber 1930
• Acrylates 1931
• Cellulose derivatives 1935
• Polystyrene 1937
• Melamine formaldehyde 1939
• Polytetrafluoroethylene 1946
• Polyethylene 1946

7
Biopolymers

• Biopolymers are obtained via polymerization of
  biobased raw materials through engineered
  industrial processes
• The raw materials of biopolymers are either
  isolated from plants and animals or synthesized
  from biomass using enzymes/ microorganisms

8
Examples of Biopolymers

• Polyesters
• Polylactic acid
• Polyhydroxyalkanoates
• Proteins
• Silk
• Soy protein
• Corn protein (zein)
• Polysaccharides
• Xanthan
• Gellan
• Cellulose
• Starch
• Chitin

• Polyphenols
• Lignin
• Tannin
• Humic acid
• Lipids
• Waxes
• Surfactants
• Specialty polymers
• Shellac
• Natural rubber
• Nylon (from castor oil)

9
Why Biopolymers

• Fossil fuels (oil gas coal) are in finite
  supply and alternative renewable sources of raw
  materials are needed
• USDAs Bioproduct Chemistry Engineering
  Research Unit focuses on creating new polymer
  technologies in which underutilized components of
  crops and their residues are processed into
  value-added biobased products.
• Most synthetic polymers are not biodegradable

10
Sustainability

• Sustainability is defined as a development that
  meets the needs of the present world without
  compromising the needs of future generations.
  Agricultural products offers this capability.

World Commission on Environment and Development
11
Biodegradable Polymers

• Polymers such as polyethylene and polypropylene
  persist in the environment for many years after
  their disposal
• Physical recycling of plastics soiled by food and
  other biological substances is often impractical
  and undesirable
• Biodegradable polymers break down in a bioactive
  environment to natural substances by enzymatic
  processes and/or hydrolysis

12
Where are BiodegradablePolymers Needed

• Packaging materials (e.g. trash bags loose-fill
  foam food containers)
• Consumer goods (e.g. egg cartons razor handles
  toys)
• Medical applications (e.g. drug delivery
  systems sutures bandages orthopedic implants)
• Cosmetics
• Coatings
• Hygiene products

13
Biodegradable Polymers Market

• Global consumption of biodegradable polymers
  increased from 14 million kg (30.8 million lbs)
  in 1996 to 68 million kg (149.6 million lbs) in
  2001
• U.S. demand for biopolymers is expected to reach
  600 million by 2005 according to a Freedonia
  Group study

U.S. Congress Office of Technology Assessment
Biopolymers Making Materials Natures
Way-Background Paper OTA-BP-E-102 (Washington
DC U.S. Government Printing Office September
1993
14
Opportunities for Biodegradable Polymers
Vegetable Oils
Oils are triglyceride esters of mixed fatty acids
where R1 R2 and R3 are saturated or
unsaturated fatty acids
15
Fatty Acid Composition of Vegetable Oils
Oil Saturated Oleic Linoleic
Linolenic Others Iodine Value Sunflower
10 30 60 - -
125 - 136 Soybean 14 30
50 6 - 120 -
141 Safflower 7 15 78
- - 140 - 150 Oiticica
10 6 6
- 78f 147 - 165 Chinese Melon
33 2 4 1 58g
120 - 130 Tung 4 7
9 - 80g 160 -
175 Linseed 8 20
19 52 - 165 -
202 Castor 3 7 5
- 85k 81 - 91 Coffee
9 46 - 45hij
100 - 111 f) Licanic acid g) Eleostearic
acid h) Palmitic i) Estearic j) Araquidic k)
Ricinoleic acid
16
Unsaturated Fatty Acids in Vegetable Oils
9-Oleic Acid
912-Linoleic Acid
91215-Linolenic Acid
Ricinoleic Acid
17
Oil-Modified Polyesters

• Oil-modified polyesters (alkyds) are synthesized
  by reacting oils polyhydric alcohols and
  polyfunctional acids
• Single largest quantity of solvent-soluble
  polymers manufactured for use in surface coatings
  industry

18
Oil-Modified Polyesters (continued)

• Oil-modified polyesters are classified into four
  categories based on their oil content
• Very long oil polyesters (gt75)
• Used in printing inks and as plasticizers for
  nitrocellulose coatings
• Long oil polyesters (60-75)
• Used in architectural and maintenance coatings as
  brushing enamels undercoats and primers
• Medium oil polyesters (45-60)
• Used in anti-corrosive primers and general
  maintenance coatings
• Short oil polyesters (lt45)
• Used with amino resins in heat-cured OEM coatings

19
Dimer Acid Polyamides (R)

• Long chain fatty acid dimers derived from
  vegetable oils are reacted with slight excess of
  primary amines to synthesize polyamides

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20
Dimer Acid Polyamides (continued)

• Polyamide-epoxy systems are the workhorse of high
  performance protective coatings

21
Epoxidized Oils

• Epoxidized oils are synthesized by reacting
  vegetable oils (typically soybean and linseed
  oils) with peracids or hydrogen peroxide
• Epoxidized oils are employed as plasticizers for
  polyvinyl chloride and as high temperature
  lubricants

22
Poly(e-caprolactone)

• As early as 1973 it was shown that
  poly(e-caprolactone) degrades in bioactive
  environments such as soil
• Poly(e-caprolactone) and related polyesters are
  water resistant and can be melt-extruded into
  sheets and bottles

23
Polyhydroxyalkanoates

• Polyhydroxyalkanoates (PHA) accumulate as
  granules within cell cytoplasm
• PHAs are thermoplastic polyesters with m.p.
  50180ºC (BiopolTM)
• Properties can be tailored to resemble elastic
  rubber (long side chains) or hard crystalline
  plastic (short side chains)

24
PHA Production
Raw materials Media preparation Fermentation
Cell disruption Washing Centrifugation Drying
PHA
Carbon source Bacteria growth and polymer
accumulation Polymer purification
25
PHB-V

• Polyhydroxybutyrate polyhydroxyvalerate (PHB-V)
  is formed when bacteria is fed a precise
  combination of glucose and propionic acid
• PHB-V has properties similar to polyethylene but
  degrades into water and carbon dioxide under
  aerobic conditions

26
Starch

• Starch is the principal carbohydrate storage
  product of plants
• Starch is extracted primarily from corn with
  lesser sources being potatoes rice barley
  sorghum and wheat
• All starches are mixtures of two glucan polymers
  amylose and amylopectin at ratios that vary
  with the source

27
Starch (continued)

• 75 of industrial corn starch is made into
  adhesives for use in the paper industry
• Corn starch absorbs up to 1000 times its weight
  in moisture and is used in diapers (gt200 million
  lb annually)
• Starch-plastic blends are used in packaging and
  garbage bag applications

U.S. Congress Office of Technology Assessment
Biopolymers Making Materials Natures
Way-Background Paper OTA-BP-E-102 (Washington
DC U.S. Government Printing Office September
1993
28
Starch (continued)

• Starch blended or grafted with biodegradable
  polymers such as polycaprolactone are available
  in the form of films
• Blends with more than 85 starch are used as
  foams in lieu of polystyrene

29
Cellulose

• Cotton contains 90 cellulose while wood contains
  50 cellulose
• Cellulose derivatives are employed in a variety
  of applications
• Carboxymethyl cellulose is used in coatings
  detergents food toothpaste adhesives and
  cosmetics applications

30
Cellulose (continued)

• Hydroxyethyl cellulose and its derivatives are
  used as thickeners in coatings and drilling
  fluids
• Methyl cellulose is used in foods adhesives and
  cosmetics
• Cellulose acetate is a plastic employed in
  packaging fabrics and pressure-sensitive tapes

31
Chitin

• Chitin a polysaccharide is almost as common as
  cellulose in nature and is an important
  structural component of the exoskeleton of
  insects and shellfish
• Chitin and its derivative chitosan possess high
  strength biodegradability and nontoxicity
• The principal source of chitin is shellfish waste

32
What is a Polymer

• A polymer is a macromolecule (large molecule)
  made of many small molecules joined together
  chemically

33
Chitosan

• Chitosan forms a tough water-absorbent oxygen
  permeable biocompatible films and is used in
  bandages and sutures
• Chitosan is used in cosmetics and for drug
  delivery in cancer chemotherapy
• Chitosan carries a positive charge (cationic) in
  aqueous solution and is used as a flocculating
  agent to purify drinking water

34
Lactic Acid

• Lactic acid is produced principally via microbial
  fermentation of sugar feedstocks
• Variation in polymerization conditions and L- to
  D- isomer ratios permit the synthesis of various
  grades of polylactic acid
• Polylactide polymers are the most widely used
  biodegradable polyesters

35
Polylactic Acid

• Polylactic acid (PLA) degrades primarily by
  hydrolysis and not microbial attack
• PLA fabrics have a silky feel and good moisture
  management properties (draws moisture away and
  keeps the wearer comfortable)
• Copolymers of lactic acid and glycolic acid are
  used in sutures controlled drug release and as
  prostheses in orthopedic surgery

36
Polyamino Acids

• Polyamino acids (polypeptides) are found in
  naturally occurring proteins
• 20 amino acids form the building blocks of a
  variety of polymers
• Polypeptides based on glutamic acid aspartic
  acid leucine and valine are the most frequently
  used

37
Amino Acid Structures
38
Polyamino Acids (continued)

• Glutamic acid and aspartamic acid are hydrophilic
  whereas leucine and valine are hydrophobic in
  nature
• Combination of these amino acids in different
  ratios permits the development of copolymers with
  varying rates of biodegradability (for use as
  drug delivery systems)

39
Polyamino Acids (continued)

• Amino acid polymers are particularly attractive
  for medical applications since they are
  nonimmunogenic (i.e. do not produce any immune
  response in animals)
• Homopolymers of aspartic acid and glutamic acid
  are water-soluble biodegradable polymers

40
Protein

• Soybeans are grown primarily for their protein
  content and secondarily for their oil
• A 60-pound bushel of soybeans yields about 48
  pounds of protein-rich meal and 11 pounds of oil
• U.S. soybean production exceeded 2500 million
  bushels in 2002

www.unitedsoybean.org
41
Soybean Protein

• Soybean protein consists mainly of the acidic
  amino acids (aspartic and glutamic acids) and
  their amides nonpolar amino acids (alanine
  valine and leucine) basic amino acids (lysine
  and arginine) and uncharged polar amino acid
  (glycine)

Alanine
Arginine
Glycine
42
Soybean Protein (continued)

• Soybean protein is available as soy protein
  concentrate soy protein isolate and defatted
  soy flour
• Soybean protein is employed in paper coatings
  with casein in adhesive formulations wood
  bonding agents and composites

43
Corn Protein

• Corn protein (zein) is a bright yellow
  water-insoluble powder
• Zein forms odorless tasteless clear hard and
  almost invisible edible films and is therefore
  used as coatings for food and pharmaceutical
  ingredients

44
Polyvinyl Alcohol

• Polyvinyl alcohol is the only polymer with
  exclusively carbon atoms in the main chain that
  is regarded as biodegradable
• Polyvinyl alcohol is used in textile paper and
  packaging industries

45
Sorona

• Sorona is a biopolyester marketed by DuPont for
  use in fibers and fabrics and is based on
  13-propanediol (derived from fermentation of
  corn sugar)
• Sorona offers advantages over both nylon and PET
  by virtue of softer feel better dyeability
  excellent wash fastness and UV resistance

46
Thames Research Group
47
Castor Acrylated Monomer
Acrylate group reacts with growing
polymer radicals
Residual unsaturation provides mechanism
for ambient cure
Alkyl moieties provide internal plasticization
48
United States Marines Utilize USM Technology
New fatigues are treated with a latex-based
product
49
VOMM-Based Textile Latex

• 12000 Marine Corps uniforms are treated monthly
  by a Mississippi-based company
• Over 100 new jobs created
• 7500 uniforms are being evaluated by the Air
  Force

50
USM Waterborne Water Repellant
USM Soy-Based Waterborne Water Repellent
Commercial Solvent-Based Water Repellent
51
Formaldehyde-Free Biodegradable Wood Composites

• Renewable
• Biodegradable
• Formaldehyde-free
• Environmentally-friendly

52
Wood Composites

• Mechanical properties were tested as per ANSI
  specifications A208.1-1999 (M-2 grade) following
  ASTM D 1037-96a
• Boards with ag-based adhesive met and even
  exceeded commercial particleboard specifications
• The adhesive is ready for a trial run in a
  commercial facility

53
Looking Ahead
54
Challenges for Biopolymers

• Competition with inexpensive commodity polymers
  familiar to the consumer
• Disposal of biodegradable polymers require an
  infrastructure and capital investment
• In absence of suitable bioconversion facilities
  biodegradable polymers are discarded in dry
  landfills and do not degrade as rapidly as
  intended

55
Farm Bill

• The Federal Biobased Procurement Program was
  authorized by Section 9002 of the 2002 Farm Bill
• Agencies will be required to purchase biobased
  industrial products whenever their cost is not
  substantially higher than fossil energy based
  alternatives when biobased industrial products
  are available and when biobased industrial
  products meet the performance requirements of the
  federal user

56
Life Cycle Analysis

• Life-cycle analysis is a technique used to
  quantify the environmental impact of products
  during their entire life cycle from raw material
  extraction manufacture transport use and
  through waste processing
• Life cycle analysis helps identify where
  improvement can be made to benefit the environment

57
Life Cycle Analysis (continued)

• Plastics production consumes energy and releases
  emissions which negatively affect the environment
• On the other hand plastics being light weight
  result in reduced material use and lower energy
  costs in transport
• Many companies are now undertaking life cycle
  analysis of their products

58
Life Cycle Analysis (continued)

• The concept of product responsibility is gaining
  importance as manufacturers and end-users must
  now consider the cradle to grave pathway of each
  product
• Life cycle analysis offers economic advantages
  for biopolymers because of their environmental
  friendliness
• Environmentally friendly products also have a
  marketing advantage as consumers are becoming
  increasingly aware of green issues

59
References

• Biodegradable Polymers for the Environment
  Richard A. Gross and Bhanu Kalra Science Vol.
  297 2 Aug 2002 p. 803807
• www.metabolix.com
• www.biobased.com
• Protective Coatings Fundamentals of Chemistry
  and Composition Clive H. Hare 1st ed.
  Technology Publishing Co. NY 1994
• www.unitedsoybean.org
• U.S. Congress Office of Technology Assessment
  Biopolymers Making Materials Natures
  Way-Background Paper OTA-BP-E-102 (Washington
  DC U.S. Government Printing Office September
  1993)
• Adhesives and Plastics Based on Soy Protein
  Products Rakesh Kumar Veena Choudhary Saroj
  Mishra I. K. Varma and Bo Mattiason Industrial
  Crops and Products 16 (2002) 155-172
• www.freemanllc.com
• Biodegradable Binders and Cross-linking Agents
  from Renewable Resources G. J. H. Buisman
  Surface Coatings International 1999(3) 127-130
• Life Cycle Assessment and Environmental Impact
  of Plastic Products T. J. ONeill ISBN
  1-85957-364-9 (www.chemtec.org)

60
Contact Information

• The University of Southern Mississippi School of
  Polymers and
• High Performance Materials
• 118 College Drive 10037
• Hattiesburg MS 39406-0001
• 601-266-4080
• www.psrc.usm.edu