the chemistry and applications of benzoxazines reporter: meng wei wang advising prof: ru jong jeng...
TRANSCRIPT
The Chemistry and Applications of Benzoxazines
Reporter: Meng Wei Wang
Advising Prof: Ru Jong Jeng
Hatsuo Ishida and Tarek Agag, Handbook of Benzoxazine Resins
Outline
Chemistry of benzoxazines Synthesis Ring-opening mechanisms
Recent development of benzoxazines Monomeric benzoxazines Main chain type Side chain type
Another applications for benzoxazine resins Conclusions
Benzoxazine (Bz) resins
1. Low cost of raw materials 5. Low water absorption2. No need for harsh catalysts 6. Low surface energy 3. No by-product 7. Superior electrical properties4. Small shrinkage in curing 8. Considerable flexibility in the molecular design.
5,6Wang, C.-F., et al ,Angew. Chem. Int. Ed. 2006, 45, 2248.7Ishida, H., et al ,J. Polym. Sci. Part A: Polym. Chem. 1994, 32, 1121.
R1
NOR2
R1
OH
N
R2n
Benzene
Oxazine
Polybenzoxazine themosets.
How to synthesize benzoxazines?
One-pot procedure (Traditional procedure)R1
N
O
R1 OH + 2 CH2O + H2N
n NH2 + (CH2O)n70oC
n
NHCH2OH
NHCH2OH
3N
N N+ 3 H2O
70oC
Brunovska, Z.; Liu, J.-P.; Ishida, H. Macromol. Chem. Phys.1999, 200, 1745.
Mechanism:
N N
NN
OH OH
1/3
N
OH
OH
NOH
N
OO
H
HO H
+ HO
H
Two-pot procedure
XH2N NH2 C
O
HH4 OH2
XN NO
O
dioxane
XHN NHHO
OH
XH2N NH2C
OHO
HXN N
HO
OH
C
H
H
S
O
O
CH3
CH3
O O
OO
2DMF
NaBH4
ethanol
CHCl3
C
O
HH
X (gel or insoluble product)
X =
for(1, 5, 9, 13)
for(2, 6, 10, 14)
for(3, 7, 11, 15)
for(4, 8, 12, 16)
(1-4) (5-8)
(9-12)
(13-16)
Lin. C.H., et al ,Polymer 2008, 49, 1220
Ring-opening mechanism of benzoxazines
What is the mechanism of polymerization?
Type I - Phenoxy structure
Ishida, H., et al , Macromolecules 2000, 33, 2839.
Type II – Phenolic structure
Ishida, H., et al , Macromolecules 2000, 33, 2839.
Main chain rearrangement
Endo, T., et al , Macromolecules 2008, 41, 9030.
The acceleration of benzoxazine polymerization (I)
Andreu, R. et al., J. Polym. Sci., Part A: Polym. Chem. 2008, 46, 3353.
When R1 is electron-withdrawing group → Decrease in the polymerization temp.When R2 is electron-withdrawing group → Increase in the polymerization temp.
Gu, Y. et al., J. Polym. Sci., Part A: Polym. Chem. 2011, 49, 1443.
The acceleration of benzoxazine polymerization (II)
Endo, T., Macromolecules 2010, 43, 1185.
Ronda, J. C., et al., J. Polym. Sci., Part A: Polym. Chem. 2008, 46, 3353.
Ishida, H., Macromolecules 2012, 45, 8119.
Outline
Chemistry of benzoxazines Synthesis Ring-opening mechanisms
Recent development of benzoxazines Monomeric benzoxazines Main chain type Side chain type
Another applications for benzoxazine resins Conclusions
Monomeric benzoxazines (I)
NOR
R'
R'
OH
N
R
R'
OH
n
Lin. C.H., et al ,Polymer 2008, 49, 1220
Sample Tg (oC) Td (oC) Char yield (%)
P(13) 208 425 52
P(F-a) 155 314 49
Poor mechanical property
Bisphenol type Diamine type
Monomeric benzoxazines (II)
Curing
Sample Tg (oC)
PPa 161
PP-appe 251
PBa 171
PB-appe 318
Takeichi, T., et al, Macromolecules 2001, 34, 7257.
Lin, C. H., et al, J. Polym. Sci. Part A: Polym. Chem. 2010, 48, 4555.
Main chain type polybenzoxazine precursors
Takeichi, T., et al, Polymer 2005, 46, 12172.
Lin. C.H., et al ,Polym. Chem. 2012, 3, 935
Side chain type polybenzoxazine precursors
Sample Tg (oC)
Va/DGEBA 174
VBa/DGEBA 143
Kimura. H., et al , J. Appl. Polym. Sci. 2001, 79, 555
Endo. T., et al , J. Polym. Sci. Part A: Polym. Chem. 2011, 49, 3174
Outline
Chemistry of benzoxazines Synthesis Ring-opening mechanisms
Recent development of benzoxazines Monomeric benzoxazines Main chain type Side chain type
Another applications for benzoxazine resins Conclusions
Another applications for benzoxazine resins (I)
Takeichi, T., et al, J. Polym. Sci. Part A: Polym. Chem. 2001, 39, 2633.
Ishida, H., et al., Polym. Chem. 2011, 49, 4335.
Takeichi, T., et al, Polymer 2008, 49, 1173.
Another applications for benzoxazine resins (II)Ishida, H., et al., Macromolecules 2012, 45, 8991.
Endo, T., et al .ACS Macro Lett. 2013, 2, 1.
Conclusions
Considerable flexibility in the molecule-design Crosslink No by-product
Future work More functionality Brittle Ring-open temperature
R1
NOR2
R1
OH
N
R2n
Thanks for your attention.