Kunal Wazarkar

STUDIES IN FLAME RETARDANT COATINGS

Presented by

Kunal D. WazarkarM.Tech in Surface Coating Technology

Research Supervisor

Dr. Anagha S. Sabnis

2

INTRODUCTION NEED OF FLAME RETARDANTS????

3

FLAME RETARDANTS??

Flame retardants are the chemicals used in thermoplastics, thermosets, textiles and coatings to inhibit or resist the spread of fire.

Two ways to achieve flame retardancy:

Additive Route Reactive Route

Physical incorporation of flame retardants

Chemical modification of polymer backbone with flame retardants

High concentration of flame retardants

Low concentration of flame retardants

Problems of phase separation, high viscosity

No such issues

4

OBJECTIVES OF THE RESEARCH To synthesize phosphorous containing flame

retardants having multiple functionalities and incorporate them in polymer backbone through reactive modification.

To modify polyurethane backbone with Phosphorous containing triol and to develop flame retardant aqueous Polyurethane Dispersions.

To synthesize un-saturation containing phosphorous based reactive flame retardants and incorporate them in unsaturated polyester backbone to prepare flame retardant unsaturated polyester composites.

5

SCHEME-1

Synthesis and Reactive Incorporation of Novel Phosphorous based Flame

Retardant in Polyurethane Dispersions

6

SYNTHESIS OF PHOSPHOROUS TRIOL

Conversion: 91.30 %

PCl

O

Cl

Cl

Phosphorus Oxychloride

HO

HN

N-Methylaminoethanol

P

O

N

N

N

OH

OH

HO

P- Containing Triol

3 0-5 degC

Ice Bath

HCl3

7

CHARACTERIZATION

Hydroxyl value

FTIR Spectroscopy 1H-NMR Spectroscopy 31P-NMR Spectroscopy

Practical Value Theoretical Value

595 mg of KOH/gm of sample

625 mg of KOH/ gm of sample.

8

FTIR SPECTROSCOPYPeaks (cm-

1)Fn group

750 & 948 P-N-C linkage

2951 -CH3

3390 -OH stretching

1463 -CH2

1031 -C-N linkage

1215 -P=O

9

1H-NMR SPECTROSCOPY

Chemical Shift

(ppm)

Protons

3.85 -OH

3.47 & 2.94 -CH2 (methylene

)

2.62 -CH3

10

31P-NMR SPECTROSCOPY

Chemical Shift: 1.94 ppm

11

FORMULATION OF FRPUDS

Raw Materials Mol.wt Eq.wt

No. of Equivalents

Conventional PUD-30 PUD-40 PUD-50

IPDI 222 111 4.4 4.4 4.4 4.4

PEG-400 400 200 1.3 0.91 0.78 0.65

FROH 269 89.67 0 0.39 0.52 0.65

DMPA 134 67 0.7 0.7 0.7 0.7

12

SYNTHESIS OF FR-PUDSStep 1: Synthesis of Urethane Prepolymer

OCN R NCO HO R' OH

COOH

HO OH

OHHO

OH

P

IPDI DMPA PEG-400 P-containing Triol

60-6

5 de

gC

DB

TD

L

COOH

NHCOOOOCHNRR

NHCOOOOCHN

R'

NHCOO

R'

OOCHN

OOCHNOOCHN

OOCHN

P

R

R

NHCOO

ROOCHN

RNCO

NHCOO

P

ROCN

NCO prepolymer

A

13

CONTD..

Step 2: Chain Extension and Neutralization of synthesized PU prepolymer

EDA, 50 degC

Chain ExtensionA

COOH

NHCOOOOCHNRR

NHCOOOOCHN

R'

NHCOO

R'OOCHN

OOCHNOOCHN

OOCHN

P

R

R

NHCOO

ROOCHN

R

NHCOO

P

RNH

NH

NH

C

O

C

O

NH

TEA

Neutralization

OOC

NHCOOOOCHN

RRNHCOOOOCHN

R'

NHCOO

R'

OOCHN

OOCHNOOCHN

OOCHN

P

R

R

HCOON

R

NHCOO

R

NHCOO

P

R

NH

NH

NH

C

O

C

O

NH

NH

COATING PROPERTIESCharacterization Commercial Conventional PUD-30 PUD-40 PUD-50

Gel Content (%) - 70.32 72.64 78.92 85.57

Mechanical Properties

DFT (µ) 40-50 45-55 50-70 50-65 45-60

Cross Cut

Adhesion

5B 4B 4B 4B 4B

Pencil Hardness HB B H 2H 4H

Scratch

Hardness

750g 750 g 1 Kg 1 Kg 1.5 Kg

Impact

Resistance

(lbs.inch)

Extrusion:

Intrusion:

70.86

70.86

70.86

70.86

64.96

47.24

59.05

35.43

47.24

35.43

Flexibility (mm) 0 0 3 3 5

Optical Properties

Gloss@600 55 30 32 37 46

Chemical Properties

Solvent Resistance

MEK <50 <50 <50 <50 <100

Xylene <50 <50 <100 <150 >200

15

THERMO-GRAVIMETRIC ANALYSIS

Samples Tonset (0C) Toffset (0C) Char yield (%)

Conventional 245 390 -

PUD-30 236 450 1.24

PUD-40 230 456 2.70

PUD-50 219 460 3.82

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PHOSPHOROUS AND NITROGEN CONTENT IN FR-PUDS

Component PUD-30 PUD-40 PUD-50

Phosphorous (wt %) 0.4 0.6 0.8

Nitrogen (wt %) 0.6 0.8 1.0

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FLAME RETARDANT PROPERTIES

Characterization PUD-30 PUD-40 PUD-50

UL-94 test VTM-1 VTM-0 VTM-0

Conventional PUD PUD-30 PUD-40 PUD-500

5

10

15

20

25

30

35

40

LOI Values

18

CONCLUSION

Phosphorous containing triol has been synthesized and successfully incorporated in PU backbone to yield FRPUDs.

Pencil and Scratch Hardness, Gloss, MEK and Xylene rub resistance, Thermal Stability

Flexibility and Impact resistance

Amount of Flame Retardan

t

19

CONTD..

Order of Flame retardancy PUD-50 (37) > PUD-40 (33) > PUD-30 (29)

Significant increase in LOI value may be attributed to the synergistic effect of phosphorous and nitrogen that has resulted in excellent overall flame retardancy of PU films.

20

SCHEME-2

Flammability Behavior of Unsaturated Polyester Composites Modified with

Un-saturation Containing Phosphorous based Reactive Flame Retardants

21

SYNTHESIS OF TRI-ALLYL PHOSPHATE (TAP)

% Conversion: 88.47 %

PCl

O

Cl

Cl

Phosphorus oxychloride

OH

Allyl alcoholexcess

P

OO

O

O

Triallyl phosphate (TAP)

Ice Bath

0-5 degC

HCl3

22

CHARACTERIZATION

Iodine value


Theoretical I.V. Practical I.V.

349.26 gm of I2/ 100 gm of sample


23

FTIR SPECTROSCOPY

Peaks (cm-

1)Fn group

1465 -CH2 group

1159 -P=O bond

987 -C=C-

776 P-O-C linkage

24

1H-NMR SPECTROSCOPYChemical

Shift (ppm)Protons

5.93 =CH-

5.36 & 5.28 =CH2 (allylic)

4.25 -CH2 (methylene)

25

31P-NMR SPECTROSCOPYChemical Shift: -0.691 ppm

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SYNTHESIS OF DTAP

PCl

O

Cl

Cl

Phosphorus oxychloride

OH

Allyl alcoholexcess

HOO

OH

Diethylene glycol

2 P

O

Cl

Cl

O OO P Cl

Cl

O

Intermediate

P

O

O

O

OO

O P

O

O

O

Ice bath

0-5 degC

Step 1

Step 2

DEG bridged Tetra-allyl phosphate (D-TAP)

% Conversion: 85.82 %

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CHARACTERIZATION

Iodine value


27

Theoretical I.V. Practical I.V.



28

FTIR SPECTROSCOPY

Peaks (cm-1)

Fn group

1456 -CH2

1180 -P=O bond

975 -C=C-

781 P-O-C bond

1220 C-O-C linkage

1H-NMR SPECTROSCOPY

Chemical Shift (ppm)

Protons

5.93 =CH-

5.38 & 5.18 =CH2 (allylic)

4.32 & 4.2 -CH2 (allylic)

3.74 -CH2 (DEG)

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31P-NMR SPECTROSCOPY

Chemical Shifts: -0.716 and

-0.741 ppm

FORMULATION OF FRUPR COMPOSITES

Composites UPR (wt%)

Styrene (wt%)

TAP (phr) DTAP (phr)

Commercial

UPR

65 35 -- --

UPR-TAP-5 65 35 5 --

UPR-TAP-10 65 35 10 --

UPR-TAP-15 65 35 15 --

UPR-DTAP-5 65 35 -- 5

UPR-DTAP-10 65 35 -- 10

UPR-DTAP-15 65 35 -- 15

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SYNTHESIS OF FRUPR COMPOSITES

O

O O

O

P

O

P

O

O

R

O

O

O

O

O

R

O

O

O

R

O

OO

R

P

O

0.02

%C

o-O

c toa

t e

2% M

EK

P

Unsaturated Polyester Styrene P-based flame retardant

Flame retardant Unsaturated Polyester Composites

33

COMPOSITE PROPERTIES Mechanical Properties:

Tensile strength and % Elongation Flexural strength Impact strength Shore D hardness

Thermal Properties: Differential Scanning Calorimetry (DSC) Thermo-Gravimetric Analysis (TGA)

Flame Retardant Properties: Limiting Oxygen Index (LOI) Underwriters Laboratories Testing (UL-94)

34

MECHANICAL PROPERTIES

0 2 4 6 8 10 12 14 1620

22

24

26

28

30

Tensile Strength Vs phr of Flame Retardant

UPR-TAP

UPR-DTAP

phr of flame Retardant

Tensile S

trength

(M

pa)

0 2 4 6 8 10 12 14 160.8

1

1.2

1.4

1.6

1.8

2

% Elongation Vs phr of Flame Retardant

UPR-TAP

UPR-DTAP

phr of Flame Retardant

% E

longati

on

35

0 2 4 6 8 10 12 14 1615

16

17

18

19

20

21

22

23

24

25

Flexural Strength Vs phr of Flame Retardant

UPR-TAP

UPR-DTAP


Fle

xura

l Str

ength

(M

pa)

0 2 4 6 8 10 12 14 160.3

0.4

0.5

0.6

0.7

0.8

0.9

Impact Strength Vs phr of Flame Retardant

UPR-TAP

UPR-DTAP


Impact

Str

ength

(K

J/m

2)

36

0 2 4 6 8 10 12 14 1666

68

70

72

74

76

78

80

82

84

86

Shore Hardness Vs phr of Flame Retardant

UPR-TAPUPR-DTAP


Sh

ore

Ha

rdn

ess

37

THERMAL PROPERTIES

DSC Curves of UPR-TAP Composites

38

DSC Curves of UPR-DTAP Composites

39

THERMO-GRAVIMETRIC ANALYSISUPR-TAP Composites

40

UPR-DTAP Composites

FLAME RETARDANT PROPERTIES

Composites Afterflame

time t1

(s)

Afterflame

time after

second flame

t2 (s)

Dripping

Behavior

UL-94 rating

Commercial

UPR

Flame doesn’t Extinguish

UPR-TAP-5 15 47 Serious

Dripping

V-2

UPR-TAP-10 8 25 No dripping V-0

UPR-TAP-15 3 17 No dripping V-0

UPR-DTAP-5 17 37 No dripping V-1



UL-94 Testing

42

Limiting Oxygen Index (LOI)

5 10 150

5

10

15

20

25

30

35

LOI Values

TAPDTAP

phr of flame retardant

LO

I V

alu

es

43

CONCLUSION Unsaturated phosphorous containing flame

retardants, TAP and DTAP were synthesized and incorporated in UPR.

The gel content of all composites was found to be in the range of 85%-90%.

Tensile strength, Shore hardness, Tg, Thermal Stability, Flame Retardancy

% Elongation, Flexural strength and Impact strength

Amount of Flame

Retardants

44

ACKNOWLEDGEMENT

My sincere thanks to

Research Guide: Dr. Anagha Sabnis

SAIF Lab, IIT Bombay All the departments of ICT Faculties and non-teaching staff Friends Family

THANK YOU

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Kunal Wazarkar