1. Research Proposal for the testing of flame retardancy of Ammonium
Polyphosphate and Expanded Graphite in a Polylactic Acid matrix polymer in
conjunction with flax and coir fibers as a biocomposite
Jason Tippie and Ben Tincher
ERAU
AE522
April 2011

2. 1
I. Introduction
Background
Fiber-reinforced materials have been known to be advantageous due to the high specific
properties and the ability to create complex shapes. These materials can be modified to satisfy
highly demanding parameters and are used in a large scope of industries from automotive and
aerospace to building and home applications. Following trends in industry and research to
develop more sustainable technology, Natural Fiber Composites (NFCs) have regained attention
to increase sustainability, recyclability, and cost effectiveness in composite materials. NFCs are
reinforced materials that contain either fibers or composite matrices, or both, that are produced
naturally or are biodegradable. The main draw of these materials is the more ‘eco-friendly’
constituents along with the lower cost of materials. Much work has been done to qualify the use
of NFCs in place of traditional composites such as glass fiber or carbon fiber.
a) Types and Applications of Natural Fiber Composites
Candidates of natural fibers for use in composites are found in many forms and in nearly
every region of the world. Wood fibers, either harvested or recycled from newspapers, have
been used for many years in reinforcement of plastic structural materials. Other non-wood fibers
typically used are straw fibers from corn, wheat, or rice, bast fibers such as flax or hemp, leaves
from plants like pineapple plants, seed fibers like those from cotton crop, or grass fibers such as
bamboo [1]. NFCs and biocomposites are currently seen in industry under a wide range of
applications. Decking and window systems are examples of the various applications of NFCs as
wood substitutes using extruded profiles [2]. Tube type profile biocomposites have provided
Europe with a biodegradable vertical drainage system used to accelerate consolidation of soft
compressible clay soils [3]. The automotive industry is also utilizing NFCs and biocomposites,
as a lightweight substitute for glass fiber reinforced composites with good sound absorption
characteristics for interior paneling [2, 4]. With ongoing research in natural composites, we will
soon see applications in railways, aircraft, irrigation systems, furniture, and sports and leisure
items as well as specially tailored lightweight structural parts and other paneling elements in the
automotive industry [4].
b) Material Characteristics
Not only are NFCs attractive due to their ‘green’ calling card, but they also offer
competitive material and production characteristics in certain applications. Studies have reported
that the final density of NFCs can be much lower than glass fiber reinforced materials, and
although the tensile strengths are much lower than glass or carbon composites, the specific
properties are more comparable. This is can be a large advantage where high strength is not
necessary but weight is an important factor. Table 1 has been constructed to compare the
material properties of several common NFCs with a more traditional glass fiber composite [2, 4,
5].

3. 2
Table 1: Material properties of common natural fibers compared to typical glass fiber
Fiber
Density
(g/cm3)
Tensile Strength
(MPa)
Young's Modulus
(GPa)
Specific Strength
(σt/ρ)
Specific Modulus
(E/ρ)
Hemp 1.50 690 70 460 47
Jute 1.30 393 26 302 20
Sisal 1.45 510 22 352 15
Flax 1.50 345 60 230 40
Coir 1.15 140 6 122 5
E-glass 2.50 3000 70 1200 28
While NFCs work well in both thermoset and thermoplastic matrix polymers, each
composite carries with it advantages and disadvantages. Thermosets yield composites that are
notably more solvent resistant, durable, and creep resistant due to the highly cross-linked chains
achieved during polymerization and allow for good fiber alignment. But, the high processing
temperatures of thermosets can lead to thermal degradation of fibers. Thermoplastics have low
processing temperatures which lead to ease of production and are much more flexible than
thermosets. Also, thermoplastics allow for much more freedom in design capabilities as they are
more easily molded or extruded. The main drawback of thermoplastics is that fiber orientation is
generally random and directional properties are harder to control.
NFCs can also be competitive with traditional fibers due to the possibility of low cost and
high availability. Natural fibers range widely in price between the many types and regions of
production. Many fibers can be grown locally such as jute or hemp and offer a new market for
farmers’ goods. Fibers such as hemp, jute, sisal, and coir generally cost around 30% the cost of
glass fibers [4], but it should be noted that the cost of NFCs is not always lower and the
availability not always higher. Flax fiber, for example, can be 30% greater in cost than glass [5].
Many factors affect cost, but as research and industry trends search for renewable technology,
NFCs may be an excellent sustainable material substitute for certain applications. This increase
in demand could lead to formation of programs, like that of the DOE [6], to implement more
domestic agricultural products yielding lower cost, higher availability, and more sustainable use
of resources [7].
c) Biocomposites
Work is also being accomplished in completely recyclable composites using natural
fibers within a biodegradable matrix. These materials, commonly known as biocomposites,
utilize polymer matrices derived so that they are biodegradable after polymerization.
Classification and definition of biopolymers has begun as research advances within this field.
Biocomposites have been found useful in structural applications to replace or to be used
alongside glass fiber reinforced plastics with comparable mechanical properties. Multilayer or
woven fabrics are used in reinforcing structural biocomposites whereas non-woven fabrics made
from relatively short fibers are used in paneling due to better draping capabilities [4]. These
composites would lead to a much higher increase in sustainability over traditional composites,
but issues arise in using these polymers. These downfalls include higher costs and shortened
useful life due to degradation. Studies to characterize degradation of these polymers [8] will
help to understand the lifespan of these materials in which case the polymer may be approved for
industrial production. But, the largest drawback of biocomposites is cost; which have been

4. 3
reported to be three to ten times [4] that of non-biodegradable matrices found in glass fiber
composites such as polyester or epoxy.
d) Processing Advantages and Disadvantages
Processing and formability of NFCs are generally less difficult than that of glass fiber
composites. Natural fibers are non-abrasive, causing less damage to processing machines [9].
And, unlike glass and carbon fibers, natural fibers are non-harmful when inhaled and cause no
skin irritation. Another attractive characteristic of natural fiber production is the lower projected
environmental impact and energy consumption [10]. Energy consumption during natural fiber
production has been estimated to be up to 80% lower than glass fiber production [9].
Because each natural fiber is much more complex chemically than silicate glass fibers,
the matrix material of an NFC is extremely important for the effectiveness as a useful material.
NFCs consist of mostly cellulose, hemicellulose, pectin, and lignin in different ratios. Each
constituent and the comparative amounts determine the behavior of the fiber within a particular
matrix. NFCs are more susceptible to degradation than traditional composites and are prone to
moisture absorption, biodegradation, and thermal and UV degradation. The hemicellulose is
very hydrophilic in which moisture is the main issue with NFCs. Moisture causes fiber swelling,
loss of mechanical strength, and alters the shape of the material [2, 9, 11, 12]. Much research is
being conducted to derive methods for fiber preparation to reduce absorption such as acetylation
treatment [11] and to increase fiber-matrix adhesion [12, 13].
e) Progress in Biocomposite Flammability and Fire Retardants
Much work as been accomplished to fabricate better performing NFCs and
biocomposites, but one area that is still immature is improving thermal stability and flammability
[14]. Biocomposites alone are not very thermal resistant, and decomposing polymers can
produce heat, smoke, and possibly harmful and combustible volatiles [15]. Therefore, a need
exists to develop techniques to improve the flammability performance of biocomposites. Many
techniques to improve flammability resistance in biocomposites are adapted from techniques
used in more traditional thermoplastic and thermoset composites. The only requirement for
techniques applied to polymer matrices or fibers is that the composite retains its biodegradability.
Commonly used techniques for biocomposites include both fire retardant additives to the matrix
and specific fiber treatments.
Between polymer and fiber decomposition, the overall composite decomposition
character is dependent mostly on the polymer. This is due to the higher volume fraction of the
polymer, previously mentioned volatiles produced, and the fact that polymers are typically more
thermally resistant than the fibers. The specific thermal decomposition process varies from
polymer to polymer carrying with it particular advantages and disadvantages. For example, a
particular polymer may exhibit better flammability characteristics than others, but it may
produce a large amount of smoke yielding it unusable in applications such as passenger carrying
ships and aircraft [16]. Therefore, polymer selection not only depends on the flammability
performance, but also the nature of thermal decomposition. Most fire retardant additives are
intumescing, or char forming, powders. When exposed to elevated temperatures, these powders
swell as they decompose, forming a char layer around the polymer and shielding it from
exposure to temperature. Some polymers are more intumescing in nature than others, which
make them more desirable for flame retardant biocomposites. The flammability properties of

5. 4
some of the most popular biopolymers have been studied [14, 17], but still much work exists in
flammability characterization and improvement of biopolymers.
Natural fiber flammability has received the most attention due to the fact that the fiber is the
weak link in composite thermal resistance. The decomposition of cellulose occurs in the range
of 260°C and 350°C which is typically lower than many biopolymer matrices [18-21]. Further,
the full decomposition of cellulose, hemicelluloses, and lignin has been characterized, and it has
been shown that lignin is the most important factor contributing to thermal resistance [18-22].
The other constituents of NFCs such as silica, as a part of the ash content, improve the
flammability properties. Therefore, it would appear that fibers with low cellulose, high lignin,
and high ash contents would be the most thermally resistant.
Not only are the polymer and fiber selection an important factors in flammability character,
but also fiber/polymer interaction. Studies have been shown that composite design does in fact
play a role in thermal resistance [23-25]. Fiber/polymer fractions and even construction
variables (shape, thickness, orientation, etc.) could possibly play a role in degradation processes.
Fiber and matrix compatibility contributes not only to the mechanical stability but also thermal
resistance. Albano et al. [26] reports that acetylated sisal fibers in a polyolefin matrix had higher
degradation temperatures than the untreated fiber composites.
Strategies for increasing fire retardancy of NFC’s range from polymer matrix additives to
fiber treatments and modifications. Commonly used fire retardant matrix additives in
biocomposites are Ammonium Polyphosphate (APP) and Expanded Graphite (EG). Other
matrix additives include Aluminum Trihydrate and Magnesium Hydroxide. Fiber additives and
modifications include the use of Diammonium Phosphate and grafting.
APP has been used as a flame retardant for many years [16] and in decomposition has been
found to evolve ammonia, water, polymeric phosphoric acid and phosphorous oxides [27] APP,
in most polymers, promotes char formation by acting in the condensed phase where acid
catalyzes dehydration reactions and cross-linking [15] EG was concluded to reduce both fire risk
and fire hazard whereas APP reduced fire risk but increased fire hazard [28] EG expands up to
300 times its initial volume when temperatures reach 900°C [29, 30] and oxidizes without
flames, consuming oxygen which smothers flames [28] Although high loading (>50% for some
polymers) is often required to achieve adequate flame retardancy, Aluminum trihydrate (ATH),
an active filler for reducing the flammability of composites [15, 25] is an effective, low-cost, and
widely used matrix additive. ATH is endothermic when decomposing, which occurs around
220°C with the endothermic peak occurring around 300°C meaning ATH begins to absorb heat
from the polymer before most composite polymers begin to degrade. Magnesium Hydroxide is
another endothermic flame retardant [15] that is stable up to 330-340°C promoting higher
processing temperatures than ATH but remains less effective than ATH because it has a
decomposition temperature comparable to most matrix polymers.
Diammonium Phosphate (DAP) is a condensed phase flame retardant, similar to APP, and
has also been used as a nondurable flame retardant for cellulosic textiles for an extended period
of time [18, 31, 32]. DAP is said to compose around 155°C, just 10°C below that of APP, which
is well below the decomposition temperature of cellulose. The phosphoric acid formed during
decomposition can phosphorylate the primary hydroxyl group of cellulose forming phosphorous
ester, which catalyze the dehydration of cellulose to promote the formation of char and water at
the expense of levoglucosan. The acid may also cross-link with the cellulose, changing the
normal pathway of pyrolysis to yield less flammable products [28]. There was little difference in
the level of flame retardancy when using DAP as a cellulosic treatment or a matrix polymer

6. 5
additive. Mohanty et al. [33] and Sabaa [34] both reported thermal stability improvements by
grafting acrylonitrile on fibers. Sabaa reported an increase in initial degradation temperature and
a reduction of weight loss and rate of degradation on sisal fibers. Mohanty et al. reported an
increased degradation temperature of 280°C from 170°C for jute grafted with acrylonitrile.
Intumescents can also be used as char promoters [15, 25]. An intumescent system consists of
3 components: a dehydrating agent that releases acid during thermal decomposition, such as
APP; a carbonizing substance which undergoes esterification with the acid, like cellulose does
with DAP, which later decomposes to form carbon, acid, water, and CO2; and a foam producing
substance which produces large quantities of nonflammable gases. The carbonizing agent,
nonflammable gases, and decomposition products all combine to form an intumescent char [15,
25, 35] which provides an insulating layer that retards heat transfer and oxygen access.
Problem statement
a. Research Goals
Biocomposites are excellent ‘eco-friendly’ replacements for traditional non-biodegradable
composites, but they currently hold particular drawbacks and issues within applications. One of
these issues is the low thermal resistance and high flammability characteristics. Building upon
work previously accomplished within the field, this work aims to characterize and maximize, for
the first time, the thermal resistance and flammability properties of polylactide (PLA)/flax and
PLA/coir composites using intumescing additives ammonium polyphosphate and expanded
graphite.
b. Hypothesis
From the findings of previous work, it is expected that composites of PLA/coir will be more
resistant to thermal degradation than PLA/flax composites due to higher lignin content in coir
fibers. It is also predicting that APP and EG will both increase thermal stability and
flammability properties. When APP and EG are used as additives together, it is presumed that
the composite performance will be better than both untreated and APP or EG separately treated
composites.
Objectives/significance of study
In attempt to further the capabilities of NFCs and biocomposites, the desired product of this
work is a biocomposite having improved flammability and thermal resistance properties. To the
best of our knowledge, there has been no attempt to combine EG and APP together as
intumescing flame retardants and no thorough study of PLA/flax and PLA/coir composites.
II. Methodology
Research design
The design of the proposed research is such that it combines the results of previously
completed work reporting the most promising methods and material selection for an industry
useable biocomposite. Selection of polymer and fibers were chosen due to their notable
flammability resistance over other biopolymer and natural fiber choices. Flame retardants were

7. 6
also selected due to their biodegradable nature and previously successful application in
biocomposites to reduce flammability.
Polylactic Acid (PLA) is a polymer useful in producing fully biodegradable biocomposites
[36]. It is currently receiving considerable attention for uses in composites for technical
applications that is produced from renewable resources [37].
Expanded Graphite is an environmentally friendly, water insoluble flame retardant that is
endothermic in combustion and known to be an effective smoke suppressant [30]. EG has been
shown useful as nanofiller for PLA to increase thermal stability as indicated in Table 2 [37].
Table 2: TGA data of neat PLA compared to PLA-EG composites (under air flow, 20°C/min).
Ammonium polyphosphate, a water-insoluble, non-melting solid with high phosphorus
content, is typically used in intumescent coatings and is an effective fire retardant [30]. APP was
used in a PLA biocomposite to impart flame retardancy and preserve the environmentally
friendly characteristic of the biocomposite [36].
It has been suggested that both coir and flax could be better choices among natural fibers for
higher thermal stability due to specific chemical composition. High lignin and low cellulose
content in coir could correspond to lower flammability. It has been shown that lignin is char-
forming and helps to insulate the composite although it has a lower decomposition temperature.
Flax fibers have lower lignin content contributing to higher decomposition temperature. Hence,
these two factors, char-formation and decomposition temperature, are inversely related. This
leads to the possibility of one factor contributing more strongly to higher thermal stability.
Test composites will all contain the same fiber volume fraction of 15 %. It has been shown
that EG in excessive amounts (greater than 6 %) increases decomposition temperatures but
decreases mechanical properties such as specific strength [37]. Previous studies have shown
promising results with APP weight percentages from 5 % to 30 % [36]. For purposes of
comparison, APP and EG contents were chosen conservatively to ensure differentiation of
results. The proposed compositions varying in additive percentages (by weight) are shown in
Table 3 below.
Sample
(%, by weight)
Temperature
for 5% weight
loss, °C
Temperature
for 50% weight
loss, °C
Temperature of the maximum
rate of degradation, °C
(from d-TGA)
PLA (granules) 339 373 377
PLA (processed) 335 372 378
PLA-4% EG 340 377 382
PLA-8% EG 345 380 385
PLA-12% EG 347 383 385

8. 7
Table 3: Proposed test composite compositions.
Sample % EG % APP
Flax000 0 0
Flax400 4 0
Flax015 0 15
Flax415 4 15
Coir000 0 0
Coir400 4 0
Coir015 0 15
Coir415 4 15
Data collection instruments
a. TGA/FTIR/DSC
Thermogravimetric analysis (TGA) involves measuring the mass change of a sample as it
exposed to a heating schedule. As the sample is heated under defined schedule, a balance inside
the furnace measures the weight change. This test method defines the decomposition of a sample
by mass loss with respect to temperature and time. Most TGA instruments have the capability to
operate within vacuum or an inert atmosphere. It is presumed that only a simple nitrogen purge
will be necessary for composite samples; although analysis results need to be closely examined
because highly sensitive thermobalances can be affected by gases within the chambers. The
sample chamber can be closed off except to an exit port where gaseous decomposition products
can be characterized by composition. TGA samples should be small in size to allow for
consistent temperature distribution and decomposition, reduce self-heating/cooling, and reduce
corrosion of testing apparatuses. Powdered samples produce the most reproducibility; otherwise,
solid samples give best results when the surface area to volume ratio is maximized [38]. TGA
tests can be accomplished under numerous heating schedules; the most simple of which are
isothermal and constant heating rate. Isothermal measurements allow for mass change at
temperature as a function of time; whereas, constant rate tests allow for mass change as a
function of temperature.
When the TGA exit gases are routed to Fourier transformation infrared (FTIR) spectroscopy
instrumentation, the composition of decomposed gases can be characterized. Infrared
spectroscopy techniques are those involving absorption measurements of infrared light. Gaining
its name, FTIR spectroscopy uses Fourier transform mathematical algorithms to complete
spectroscopy measurements across a wide range of wavelengths as opposed narrow ranges.
Absorption of specific light wavelengths corresponds to specific elemental bonds which gives
clues to the composition and structure of a substance. FTIR spectroscopy can be applied to any
phase of material and is often used for gas analysis [39].
Differential scanning calorimetry (DSC) measures the change in heat capacity, cp, of a
material as a function of temperature. As the sample is heated or cooled, changes in heat
capacity represent material transition points; therefore, the structural history can be monitored
throughout a heating or cooling range. Common structural transitions include glass transition,
phase changes, or curing. Most accurate results are obtained from sealed platinum or aluminum
pans that hold the material. For DSC measurements, the heating rate is constant and user defined
[40].

9. 8
b. LOI and Flammability tests
The limiting oxygen index (LOI) of a composite is a measurement of a material’s ability to
burn under limited oxygen supply. The test includes a sample strip suspended vertically inside
of a cylindrical chamber often made of silica that is ignited from the bottom and a
nitrogen/oxygen mixture is pumped through the chamber. The ratio of oxygen in the mixture is
controlled to decrease at a steady rate. When the flame is extinguished, the ratio of oxygen to
nitrogen content is taken as the LOI expressed as a percentage of oxygen to nitrogen. In this
way, higher LOI values represent decreased flammability [41].
Another common flammability test is the vertical burn test. In this test, samples are again
mounted vertically and ignited from the bottom in open air. Once the material is ignited the
flame source is removed. The time for the sample to move a particular distance up the sample is
then recorded. Comparisons are made between sample burn rates in length per time. This test
offers a direct comparison of how quickly a material will propagate a flame and is an excellent
differentiation between similar materials. If a sample does not continue to burn once the flame
source is removed, the time of burn is not recorded and the material is classified as ‘self
extinguishing’. Other characteristics of burning should be recorded such as ceasing to burn after
a short time, dripping, or visible gases/smoke [41]. Federal aviation regulations require vertical
burn tests; therefore, this test is applicable to possible industry applications.
Data collection
Embry-Riddle Aeronautical University (ERAU) does not currently have TGA, DSC, and
FTIR capabilities. It is known that University of Central Florida (UCF) Department of
Chemistry in Orlando, Florida has these capabilities and contact will be made about the
possibility of use of these instruments. LOI tests will be made at ERAU although there is no
current setup for these tests. The necessary apparatuses, materials, controllers, and sensors will
need to be purchased for the completion of these tests. Test samples for all tests will be made at
ERAU.
Data analysis
Since composite fabrication will involve varied fiber and matrix volume fractions, data
gathered from TGA experiments will be interpreted as mass percents highlighting the
decomposition of either fiber or matrix. FTIR spectroscopy will allow characterization of gases
evolved during composite decomposition. These gases can then be classified as toxic or problem
causing for proposed applications of studied biocomposites. DSC will allow for specific analysis
of the composite decomposing process. Structural changes in both polymer and fibers can be
monitored by DSC. Careful consideration will be taken into correlating the data gathered from
these experiments. Combining TGA and DSC data may give clues as to which polymer phase or
stage of composite decomposition is the most crucial to overall composite flammability
performance.
III. Limitations
Foreseen limitations of this work include quality of composite fabrication, availability of
resources, and the necessary completion of TGA/DSC/FTIR testing outside of ERAU.
Fabrication of composite samples will be attempted by the authors who have little to no previous

10. 9
composite experience. Since overall composite construction is an important parameter for
thermal resistance, it may be necessary to have the composites fabricated outside of ERAU or by
experienced composite technicians. Attempts have been made to contact the chemistry
department at UCF, but no response has been received yet. With given permission, testing will
be relatively simple as UCF is very close to ERAU. Without permission, other sites of testing
will be necessary, possibly the University of Florida or Florida State University. Resources for
this project include all project costs and sufficient time to fabricate samples, run tests, and
analyze results. Costs will include composite materials, LOI testing materials, and possible
rental costs for out-of-house testing.
References
1. Mohanty,A.,Misra, M., et al., NaturalFibers,Biopolymers,and Biocomposites,inNaturalFibers,
Biopolymers, and Biocomposites. 2005, CRC Press.
2. Saheb, D.N. and Jog, J.P., Natural fiber polymer composites: A review. Advances in Polymer
Technology, 1999. 18(4): p. 351-363.
3. Luo, S. and Netravali, A.N., Interfacial and mechanical properties of environment-friendly
“green” composites made from pineapple fibers and poly(hydroxybutyrate-co-valerate) resin.
Journal of Materials Science, 1999. 34(15): p. 3709-3719.
4. Mohanty, A.K., Misra, M., and Hinrichsen, G., Biofibres, biodegradable polymers and
biocomposites:An overview. MacromolecularMaterialsand Engineering, 2000. 276-277(1): p. 1-
24.
5. A.K. Bledzki, J.G., Natural Fiber Reinforced Plastics, in Handbook of Polymeric Engineering
Materials, N.P. Cheremisinoff, Editor. 1997, Marcel Dekker, Inc.: New Jersey. p. 787.
6. THE TECHNOLOGY ROADMAP FOR PLANT/CROP-BASED RENEWABLE RESOURCES 2020
1999, http://www1.eere.energy.gov/biomass/pdfs/technology_roadmap.pdf
7. Mohanty, A.K., Misra, M., and Drzal, L.T., Sustainable Bio-Composites from Renewable
Resources:Opportunitiesand Challengesin the Green Materials World. Journal of Polymers and
the Environment, 2002. 10(1): p. 19-26.
8. Amass, W., Amass, A., and Tighe, B., A review of biodegradable polymers: uses, current
developments in the synthesis and characterization of biodegradable polyesters, blends of
biodegradablepolymersand recent advancesin biodegradation studies. Polymer International,
1998. 47(2): p. 89-144.
9. Bismarck,A.,Mishra,S., and Lampke,T., Plant Fibers as Reinforcement for Green Composites, in
Natural Fibers, Biopolymers, and Biocomposites. 2005, CRC Press.
10. Joshi,S.V.,Drzal,L.T.,etal., Are natural fiber composites environmentally superior to glass fiber
reinforced composites? Composites Part A: Applied Science and Manufacturing, 2004. 35(3): p.
371-376.
11. Bledzki, A.K. and Gassan, J., Composites reinforced with cellulose based fibres. Progress in
Polymer Science, 1999. 24(2): p. 221-274.
12. Herrera Franco, P. and Valadez-Gonz√°lez, A., Fiber-Matrix Adhesion in Natural Fiber
Composites, in Natural Fibers, Biopolymers, and Biocomposites. 2005, CRC Press.
13. George, J., Sreekala, M.S., and Thomas, S., A review on interface modification and
characterization of natural fiber reinforced plastic composites. Polymer Engineering & Science,
2001. 41(9): p. 1471-1485.
14. Matkó, S., Toldy, A., et al., Flame retardancy of biodegradable polymers and biocomposites.
Polymer Degradation and Stability, 2005. 88(1): p. 138-145.
15. Mouritz, A.P. and Gibson, A.G., Fire Properties of Polymer Composite Materials. 2006: Springer.

11. 10
16. Lyons, J.W., ed. Synthetic Polymers with All-carbon Backbones. The Chemistry & Uses of Fire
Retardants. 1970, Wiley-Interscience: New York.
17. Wu, K., Hu, Y., et al., Flame Retardancy and Thermal Degradation of Intumescent Flame
Retardant Starch-Based Biodegradable Composites. Industrial & Engineering Chemistry
Research, 2009. 48(6): p. 3150-3157.
18. Horrocks, A.R., An Introduction to the Burning Behaviour of Cellulosic Fibres. Journal of the
Society of Dyers and Colourists, 1983. 99(7-8): p. 191-197.
19. Russell, L.J., Marney, D.C.O., et al., Combining Fire Retardant and Preservative Systems
forTimber Products inExposed Applications - State of the Art Review. 2004, Forest and Wood
Products R&D Corporation: Victoria.
20. Shafizadeh, F., The Chemistry of Pyrolysis and Combustion, in The Chemistry of Solid Wood.
1984, American Chemical Society. p. 489-529.
21. LeVan,S.L.and Winandy,J.E., Effectsof Fire RetardantTreatmentson Wood Strength. Woodand
Fiber Science, 1990. 22(1): p. 113-131.
22. Manfredi, L.B., Rodríguez, E.S., et al., Thermal degradation and fire resistance of unsaturated
polyester,modified acrylic resins and their composites with natural fibres. Polymer Degradation
and Stability, 2006. 91(2): p. 255-261.
23. Hshieh, F.-Y. and Beeson, H.D., Flammability testing of flame-retarded epoxy composites and
phenolic composites. Fire and Materials, 1997. 21(1): p. 41-49.
24. Brown,J.R.,Fawell,P.D.,andMathys,Z., Fire-hazard assessmentof extended-chain polyethylene
and aramid composites by cone calorimetry. Fire and Materials, 1994. 18(3): p. 167-172.
25. Kandola,B.K.and Kandare, E., Composites Having Improved Fire Resistance, in Advances in Rire
Retardant Materials, A.R. Horrocks and D. Price, Editors. 2008, Woodhead: Cambridge.
26. Albano,C.,González, J., et al., Thermal stability of blends of polyolefins and sisal fiber. Polymer
Degradation and Stability, 1999. 66(2): p. 179-190.
27. Camino,G.,Costa, L.,et al., Study of the mechanism of intumescence in fire retardant polymers:
PartVI--Mechanism of ester formation in ammonium polyphosphate-pentaerythritol mixtures.
Polymer Degradation and Stability, 1985. 12(3): p. 213-228.
28. Chapple, S. and Anandjiwala, R., Flammability of Natural Fiber-reinforced Composites and
Strategies for Fire Retardancy: A Review. Journal of Thermoplastic Composite Materials. 23(6):
p. 871-893.
29. Schilling, B., Expandable graphite. Kunststoffe-Plast Europe, 1997. 87(8): p. 1004-1005.
30. Schartel, B., Braun, U., et al., Fire retardancy of polypropylene/flax blends. Polymer, 2003.
44(20): p. 6241-6250.
31. Lewin, M. and Sello, S.B., Technology and Test Methods of Flame Proofing of Cellulosics, in
Flame-Retardant Polymeric Materials, M. Lewin, S.M. Atlas, and E.M. Pearse, Editors. 1975,
Plenum Press: New York. p. 19-136.
32. Schindler,W.D.andHauser,P.J., Flame-retardantFinishes,inChemicalFinishing of Textiles, W.D.
Schindler and P.J. Hauser, Editors. 2004, Cambridge: Woodhead. p. 98-116.
33. Mohanty, A.K., Patnaik, S., et al., Graft copolymerization of acrylonitrile onto acetylated jute
fibers. Journal of Applied Polymer Science, 1989. 37(5): p. 1171-1181.
34. Sabaa, M.W., Acrylonitrile asTheral Stabilizer forSisal Fibers. PolymerDegradationandStability,
1991. 32: p. 209-274.
35. Wladyka-Przybylak,M., The Thermal Characteristics of Different intumescent Coatings. Fire and
Materials, 1999. 23: p. 33-43.
36. Shumao, L., Jie, R., et al., Influence of ammonium polyphosphate on the flame retardancy and
mechanical properties of ramie fiber-reinforced poly(lactic acid) biocomposites. Polymer
International, 2010. 59(2): p. 242-248.

12. 11
37. Murariu, M., Dechief, A.L., et al., The production and properties of polylactide composites filled
with expanded graphite. Polymer Degradation and Stability, 2010. 95(5): p. 889-900.
38. Brown, M.E., Introduction to Thermal Analysis. Second ed. 2001: Kluwer Academic.
39. Introduction to Fourier Transform Spectroscopy. 2001, Thermo Nicolet Corporation.
40. Frequently Asked Questions: Differntial Scanning Calorimetry, P. Elmer, Editor. 2010.
41. Brent Strong, A., Flammability Testing, Brigham Young University.