Composites Design and Manufacture (Plymouth University teaching support materials)
Environmental resistance of composites.
PowerPoint 15MB

1 MB reduced version
ACMC logo

The key texts for the durability of composites include:

Go direct to ...

Composites in aerospace environments

In the design of composites for aerospace environments, it is necessary to consider that a typical aircraft will be exposed to very low temperatures at cruising height and very high temperatures on the ground in the desert (typically in the range -60 to +60 ºC) and also an extreme range of humidities. In consequence, a key design constraint is the hot-wet glass transition temperature, Tg.

Composites in the marine environment

For general background on Materials in a Marine Environment see, for example:

Additional sources specific to composites include:

Naval vessels

Vosper Thornycroft lead the way to glass fibre reinforced naval vessels with the 450 tonne displacement HMS Wilton launched in January 1972 and commissioned in July 1972.  They subsequently developed the Hunt class MCMVs (Mine Counter Measures Vessels) at 725 tonne displacement with the first HMS Brecon launched in June 1978 and commissioned in March 1980.  The first 450 tonne Sandown Class SRMH (Single Role Mine Hunter) HMS Sandown was launched in April 1988 and commissioned in June 1989.

The Visby Class of stealth corvettes is being built for the Swedish Navy by the Swedish company Karlskronavarvet.  Construction began in 1996.  The 600 tonne displacement Visby (K31) was launched in June 2000 and began sea trials in February 2001.  She is due to enter operational service in January 2005.  The hull material is a sandwich construction comprising a PVC core with a carbon fibre and vinyl laminate.  The material provides high strength and rigidity, low weight, good shock resistance, low radar and magnetic signature.

Yacht and dinghy hulls

Mirabella V, the largest single masted yacht in the world, was launched in November 2003 and her mast was stepped during December.  The 765 tonne (half load displacement) vessel, built by Vosper Thornycroft, has an overall length of 75.22m (247 ft), beam of 14.80m (48.5 ft), draught (keel up) of 4.0m (13 ft), draught (keel fully down) of 10.0m (33 ft) and the mast height is 88.5m (290ft).

Tanks and Pipelines for the Oil and Gas Industry

The Corrosion Resistant Structures Committee of the Reinforced Plastics / Composites Institute within the Society of the Plastics Industry, Inc. [355 Lexington Avenue, New York, New York 10017. (212) 573 9400] has published a guide to assist prospective buyers of glass fibre Reinforced Plastic (RP) tanks.

Other applications of composites in the marine environment include:


The recommended texts for the durability of composites in the marine environment are:

The saturation moisture content of materials (Mmax%) is dependent on the polymer chemistry as indicated in Table 1:

Table 1:  Saturation moisture content
Mmax% characteristic examples Reference
<0.5% only apolar groups polyolefins, PTFE, polystyrene, polydimethylsiloxane 1
<3.0% non-hydrogen donors polyethers, polyesters, cured epoxy 1
<10% H-donors in hydrogen bonding polyvinylalcohol, polyacrylic acid, polyacrylamide 1
10.5-12.3% natural fibres flax, hemp, jute, sisal 2

Wright [3] plotted the fall in glass transition temperature (Tg) as a function of moisture content for data from epoxy resins (from five separate published papers)and found "as a rough rule-of-thumb" that there was a drop of 20°C for each 1% of water pick-up (data available up to 7% moisture content).  For saturated PMMA at 1.92% water pick-up, the Tg was depressed by ~20°C [4].  For PLA microspheres, Tg was reduced from 52°C (~0.3% H2O) to 37°C (3.5% H2O), implying a need for the cautious design of PLA matrix composites to be used in humid tropical environments [5].

Swelling of materials is measured by a Coefficient of Hygroscopic Expansion (CHE, β), also known as the swelling- or moisture- expansion coefficients, and defined as as the strain ε induced by a variation of 1% of moisture content Δm. Anisotropic materials will have different CHE in each direction, but for natural fibres there will be just a longitudinal (axial) and transverse (radial) CHE.  Some typical values are given in Table 2.

Table 2:  Coefficient of Hygroscopic Expansion (CHE, β)  with some data via [6]  beware unchecked conversions between units!
Materialε/Δm TechniqueReference
Hexcel carbon/epoxy UD composite
parallel to fibres.
T7G145/F584-4 UD prepreg tape
0.018size measurement 7
Hexcel carbon/epoxy UD composite
45° to fibres in-plane
0.206size measurement 7
Hexcel carbon/epoxy UD composite
normal to fibres in-plane
0.241size measurement 7
Hexcel carbon/epoxy UD composite
through plate thickness
0.412-0.533size measurement 7
carbon/epoxy quasi-isotropic laminate
Toray T800H/#3631 [0°/±45°/90°]s
0.0-0.0047 assumed,
not measured
epoxy resin 0.003   9
epoxy (unfilled) 0.22 size measurement 10 via 6
flax single fibre1.14 (radial)   11
moulding compounds 0.16-0.27 Moiré interferometry 12 via 6
moulding compounds 0.24-0.26 Size measurement 13 via 6
moulding compounds 0.45-1.53 TMA/TGA 14 via 6
wood fibres0.3 (radial)   15 via 11
wood fibres0.45 (radial)   16 via 11
  1. X Colin and J Verdu, Humid geing of organic matrix composites, in P Davies and YPS Rajapakse (editors), Durability of composites in a marine environment, Springer, 2014, 47-114.
  2. Célino et al, Characterization and modeling of the moisture diffusion behavior of natural fibers, Journal of Applied Polymer Science, 5 October 2013, 130(1), 297-306.
  3. WW Wright, The effect of diffusion of water into epoxy resins and their carbon fibre reinforced composites, Composites, July 1981, 12(3), 201-205.
  4. L Smith and V Schmitz, The effect of water on the glass transition temperature of poly(methyl methacrylate), Polymer, October 1988, 29(10), 1871-1878.
  5. N Passerini and DQ Craig, An investigation into the effects of residual water on the glass transition temperature of polylactide microspheres using modulated temperature DSC, Journal of Controlled Release, 18 May 2001, 73(1), 111-115.
  6. A Teverovsky, Environmentally induced swelling and shrinkage of molding compounds in [plastic encapsulated microcircuits] PEMs, NEPP Report, January 2002.
  7. HS Choi, KJ Ahn, J-D Nam and HJ Chun, Hygroscopic aspects of epoxy/carbon fiber composite laminates in aircraft environments, Composites Part A: Applied Science and Manufacturing, 1 May 2001, 32(5), 709-720.
  8. K Ogi, HS Kim, T Maruyama and Y Takao, The influence of hygrothermal conditions on the damage processes in quasi-isotropic carbon/epoxy laminates, Composites Science and Technology, 1 December 1999, 59(16), 2375-2382.
  9. DS Cairns and DF Adams, Moisture and thermal expansion properties of unidirectional composite materials and the epoxy matrix, Journal of Reinforced Plastics and Composites, 1983, 2(4), 239-255.
  10. MR Vanlandingham, RF Eduljee and JW Gillespie, Moisture diffusion in epoxy systems, Journal of Applied Polymer Science, 1999, 71(5), 787-798.
  11. A le Duigou, J Merotte, A Bourmaud, P Davies, K Belhouli and C Baley, Hygroscopic expansion: A key point to describe natural fibre/polymer matrix interface bond strength, Composites Science and Technology, 20 October 2017, 151, 228-233.
  12. E Stellrecht, B Han and M Pecht, Characterization of hygroscopic strains due to hygroscopic swelling coefficient mismatches in PEMs, IEEE Transcations on Components and Packaging Technology, September 2004, 27(3), 499-506.  CALCE report C2-20, 2002.
  13. LT Nguyen, KL Chen, J Schaefer, AY Kuo and G Slenski, A new criterion for package integrity under solder reflow conditions, Proceedings of the 45th Electron Components and Technology Conference, Las Vegas NV, IEEE, 21-24 May 1995, 478-490.
  14. EH Wong, KC Chan, R Rajoo and TB Lim, The mechanics and impact of hygroscopic swelling of polymeric materials in electronic packaging, Proceedings 50th Electronic Components & Technology Conference, Las Vegas NV, IEEE, 21-24 May 2000.
  15. T Joffre, RC Neagu, SL Bardage and EK Gamstedt, Modelling of the hygroelastic behaviour of normal and compression wood tracheids, J. Struct. Biol., 2014, 185, 89-98.
  16. T Joffre, P Isaksson, PJJ Dumont, S Rolland du Roscoat, S Sticko, L Orgeas and K Gamstedt, A method to measure moisture induced swelling properties of a single wood cell, Experimental Mechanics, 2016, 5.

Osmosis and blistering (and how to avoid it !)

See Searle and Summerscales (referenced above), the PassionForPaint website or the West System page entitled Worrying About Osmosis?

The Ken Hankinson book How to Fiberglass Boats (2nd edition)  claims to present the most up-to-date and complete information available from a single source for anyone interested in covering new or used boats with a protective layer of fibreglass using either polyester or epoxy resins. This easy-to-read book takes the fear and mystery out of fibreglass work and helps the amateur avoid costly and tedious pitfalls. The clearly described methods are both simple and proven, making a first-class job possible by anyone willing to follow the easy non-technical instructions. Topics include fibreglass sheathing materials and which to use, resins, hardeners, catalysts, pigments, "wet" and "dry" application methods, "tips" the pros use, safety aspects, estimating materials, surface prep for both old and new boats, finishing methods, and much more! In addition to fibreglass, alternative materials such as polypropylene, "Dynel", "Arabol", "Kevlar" and carbon fibre are covered as they apply to sheathings.

Deep submergence

There are facilities for deep submergence testing at:

Cavitation Erosion

Under certain conditions liquids can change to the vapour phase. This phenomenon, known as cavitation, imposes serious limitations on pumps, pipelines and propulsion systems if damage is to be avoided:

Karimi and Martin have reviewed the cavitation erosion of materials. A book by Tillner et al has the specific aim of damage limitation and damage avoidance in pumps and their installations. Micrographs of cavitation damage in metals are presented in The Atlas of Metal Damage.

The University of Newcastle Marine Technology cavitation tunnel publications are listed on-line.

Hiroharu Kato has an online bibliography for cavitation in hydrofoils and propellers (201 papers at 08 October 2004).

The Copper Development Association has published data on cavitation erosion resistance.

The published work on cavitation erosion of polymeric materials, and especially composites, is very limited [1-10]:

  1. V Schroeder, Cavitation erosion tests with polyamid specimens and stainless steel specimens, Zeitschrift fur Werkstofftechnik – Materials Technology and Testing, 1986, 17(10), 378-384 (in German)
  2. RB Bhagat, Cavitation erosion of composites – a materials perspective, Journal of Materials Science Letters, 1987, 6(12), 1473-1475.
  3. PV Rao, Evaluation of epoxy-resins in flow cavitation erosion, Wear, 1988, 122(1), 77-95.
  4. H Bohm, S Betz and A Ball, The wear-resistance of polymers, Tribology International, 1990, 23(6), 399-406.
  5. DA Hammond, MF Amateau and RA Queeney, Cavitation erosion performance of fiber-reinforced composites, Journal of Composite Materials, 1993, 27(16), 1522-1544.
  6. S Gowing, P Coffin and C Dai, Hydrofoil cavitation improvements with elastically coupled composite materials, Proc. 25th American Towing Tank Conference, Iowa City IA, 1998.
  7. Yong-Zik Kim, Jung-Ju Lee, Soon-Chul Kwon, Yun-Hae Kim (Korea Maritime University), Minimizing of cavitation-erosion damage for various mechanical structures using composites under the various condition of fluid flow system, ICCE-7, Denver CO, 2-8 July 2000.
  8. New composites reduce cavitations in giant marine propeller tests, Materials World, July 2003, 11(7), 8.
  9. T Yamatogi , H Murayama , K Uzawa , K Kageyama and N Watanabe, Study on cavitation erosion of composite materials for marine propeller, ICCM-17, Edinburgh, Scotland July 27-31, 2009.
  10. R Guobys, Á Rodríguez and L Chernin, Cavitation erosion of glass fibre reinforced polymer composites with unidirectional layup, Composites Part B: Engineering, 15 November 2019, 177, 107374.

Galvanic Corrosion

The corrosion of metals and semiconductors involves the flow of an electric current within the material.  Most of the constituent materials in fibre-reinforced laminates are insulators and, in consequence, electrochemical corrosion is not an issue.  However, carbon (graphite) acts as a noble metal, lying between platinum and titanium in the galvanic series.  Carbon fibres should not be used where they can come into contact with structural metals (especially aluminium or magnesium) in the presence of a conducting fluid (eg sea-water).  A thin glass fibre surface layer may be sufficient to prevent the formation of such a galvanic corrosion cell.


Summerscales [1] has reviewed the use of organisms and enzymes for (a) extraction of fibres from plant material (retting), (b) surface modification of fibres, and (c) end-of-life treatments, in the context of bast fibres and their composites.  The use of enzyme processes at large scale is limited by the extended treatment times, costs of the enzymes and equipment, wastewater treatment and the current low level of adoption by industry.

A new esterase class of enzymes (PETases) has recently been identified that can catalyse the hydrolysis of poly(ethylene terephthalate) [2-5]. Although the result is specific to a high performance (high melting point) thermoplastic system, it does indicate that it may be practical to develop similar systems to process unsaturated polyester thermoset resin matrices.

Pangallo et al [6] isolated fungal and bacterial microflora from an epoxy resin used in the creation and conservation of sculptures.  The microbial community composed of rock-inhabiting members, algal photobionts (Trebouxia spp., Chloroidium ellipsoideum and Chlorella angustoellipsoidea), Cyanobacteria (Leptolyngbya sp., Phormidium sp., Cylindrospermum stagnale, Hassallia byssoidea and Geitlerinema sp.), black yeasts related to the species Friedmanniomyces endolithicus, Pseudotaeniolina globosa, Phaeococcomyces catenatus and Catenulostroma germanicum and several plant-associated fungi.  Eliaz et al [7] identified that synergistic bacterial growth took place during biodegradation of epoxy resin when Rhodococcus rhodochrous and Ochrobactrum anthropi were the only carbon source available for the microrganisms.

  1. J Summerscales, A review of bast fibres and their composites: Part 4 ~ organisms and enzyme processes, Composites Part A: Applied Science and Manufacturing, January 2021, 140, 106149.
  2. X Han, W Liu, J-W Huang, J Ma, Y Zheng, T-P Ko, L Xu, Y-S Cheng, C-C Chen and R-T Guo, Structural insight into catalytic mechanism of PET hydrolase, Nature Communications, 2017, 8, article #2106.
  3. HP Austin, MD Allen, BS Donohoe, NA Rorrer, FL Kearns, RL Silveira, BC Pollard, G Dominick, R Duman, K El Omari, V Mykhaylyk, A Wagner, WE Michener, A Amore, MS Skaf, MF Crowley, AW Thorne, CW Johnson, HL Woodcock, JE McGeehan and GT Beckham, Characterization and engineering of a plastic-degrading aromatic polyesterase, Proceedings of the National Academy of Sciences, 8 May 2018, 115(19), E4350-E4357.
  4. C-C Chen, X Han, T-P Ko, W Liu and R-T Guo, Structural studies reveal the molecular mechanism of PETase, The FEBS Journal (Federation of European Biochemical Societies), October 2018, 285(20), 3717–23.
  5. HF Son, IJ Cho, S Joo, H Seo, H-Y Sagong, SY Choi, SY Lee and K-J Kim, Rational protein engineering of thermo-stable PETase from Ideonella sakaiensis for highly efficient PET degradation, ACS Catalysis, 2019, 9(4), 3519-3526.
  6. D Pangallo, M Bučková, L Kraková, A Puškárová, N Šaková, T Grivalský, K Chovanová and M Zemánková, Biodeterioration of epoxy resin: a microbial survey through culture-independent and culture-dependent approaches, Environmental Microbiology, February 2015, 1792), 462-479.
  7. N Eliaz, EZ Ron, M Gozin, S Younger, D Biran and N Tal, Microbial degradation of epoxy, Materials, 2018, 11(11), 2123.


The National Paint and Coatings Association glossary contains terms used commonly in the paint and coatings industry to describe the characteristics, usage and components of paints and coatings.

PaintSquare is the on-line home of The Journal of Protective Coatings & Linings (JPCL) and Protective Coatings Europe (PCE) and a portal to the protective and marine coatings industry.

Since its inception in 1926, the Paint Research Association (PRA) has been the premier research association in the coatings field.  Today, it is the largest independent coatings centre of its kind, basing itself on a worldwide membership, trans-national activities and a global network of contacts.

The Oil & Colour Chemists Association was founded in 1918. More commonly known as OCCA, it is a learned society comprising individual, qualified persons employed in, or associated with, the world-wide surface coatings industries. The majority of its Members are working in a technical capacity, however its membership includes senior personnel in many roles throughout the surface coating industries. The word 'Oil' in its title refers to the vegetable oils, which once formed a major part of surface coatings' formulations.

VIDEO: Tony Ryan, Watching Paint Dry, 2011

ANTI-FOULING TECHNOLOGIES ... this section has been moved: click here


Mouritz and Gibson [2006 book] have published a book which covers all of the key issues on the behaviour of composites in a fire, including thermal degradation mechanisms, thermal softening, fire damage mechanics, and deterioration of mechanical properties. Also covered are fire protection materials for composites, fire properties of nanocomposites, fire safety regulations and standards, fire test methods, and health hazards from burning composites.

The International Maritime Fire and Rescue Information website FireNet (Maritime) includes a Special Interest Network being developed to cover Ship Fire Fighting Techniques, Training, Procedures and any interesting marine related topics within this type of environment.

NoFire Technologies are manufacturers of patented high performance fire retardant paint and products.  They specialise in research, design and engineering of fire and heat protection system solutions for industry, government and public safety.  After extensive independent and Naval testing, NoFire A-18 NV is been listed on the U S Navy Qualified Products List (QPL) and NoFire A-18 Fire Retardant Marine Paint is approved by US Coast Guard for use on all ships.

References for Fire, Smoke and Toxicity (FST)

Further reading

  1. SC Dexter, Handbook of oceanographic engineering materials, Wiley, New York & Chichester, 1979. ISBN 0-471-04950-6.  PU CSH Library
  2. Stan Grainger and Jane Blunt, Engineering coatings: design and application, Abington, 1998. ISBN 1-85573-369-2.  PU CSH Library.
  3. Eric Greene Associates, Marine composites (second edition), Eric Greene Associates, 1999. ISBN 0-967369-20-7.  PU CSH Library.
  4. R Lambourne and TA Strivens, Paint and surface coatings: theory and practice, Woodhead, Cambridge, 1999. ISBN 1-85573-348-x.  PU CSH Library.
  5. C Mahieux, Environmental Degradation of Industrial Composites, Elsevier Science, 2005. ISBN 1-85617-447-6.
  6. R Martin, Ageing of composites, Woodhead Publishing, Cambridge, 2008. ISBN-13: 978-1-84569-352-7.  PU CSH Library.
  7. Geoffrey Pritchard, Reinforced plastics durability, Woodhead, Cambridge, 1999. ISBN 1-85573-320-x.  PU CSH Library.
  8. CS Smith, Design of marine structures in composite materials, Elsevier Applied Science, 1990. ISBN 1-85166-416-5.
  9. NA Waterman and AM Pye, Guide to the selection of materials for marine applications, Fulmer Research Institute, Slough, 1980.  PU CSH Library.
  10. KD Weiss, Paint and coatings: A mature industry in transition, Progress in Polymer Science, 1997, 22(2), 203-245.
  11. JM Hutchinson, Physical aging of polymers, Progress in Polymer Science, 1995, 20(4), 703-760.

Return to MATS 347 home page
Updated by John Summerscales on 07-Feb-2022 19:38. Terms and conditions. Errors and omissions. Corrections.