characterization of polymerization of isocyanate resin and ... · characterization of...
TRANSCRIPT
Characterization of Polymerization of
Isocyanate Resin and Phenolic Resins of
Different Molecular weights.
Part I: morphology and structure analysis
Xiaomei Liu
Department of Sustainable Bioproducts
Mississippi State University
SWST 2015 International Convention
Outline
1. Background
2. Materials and Methods
3. Results and Discussion
4. Conclusions
5. Further study
1. Background
PF resins has the properties of good heat resistance ,
dimensional stability, chemical resistance.
It is brittle in nature and limits its applications.
PF resins contain a hydroxyl group and thus have the
potential to interact with other polymers.
MDI reacts easily with chemicals which contain hydroxyl
group and forms polyurethane elastomer.
R—N=C=O + OH- R’ === R—NHCOOR’
Reference:Wu, Hew-Der, Peter P. Chu, and Chen-Chi M. Ma. "Thermodynamic properties of the novolac type
phenolic resin blended with poly (hydroxyl ether of bisphenol A)." Polymer 39.3 (1998): 703-709.
2. Materials and Methods
MaterialsPhenolic resins: 90%, from Fisher
Formaldehyde: 50%, from Georgia Pacific
NaOH: 100%, from Fisher
MDI: M20 isocyanate, from BASF
During the cooking procedure, get different viscosities of A,
B, D, M, W using Tube type viscometer. According to
Mark–Houwink–Sakurada equation:
Where η is the intrinsic viscosity, M is the molecular weight.
α and K is the Mark-Houwink Parameters.
Reference:Pilato, Louis. Phenolic resins: a century of progress. New York: Springer, 2010.
2. Materials and Methods Methods:Transmission Electron Microscope (TEM)
JEOL JEM-2100 LaB6 TEM , 200 keV
X-ray diffraction analysis (XRD)
Ultima III Lab X-ray diffraction system
(λ=0.15418 nm); 40 kV and 44 Ma; 1º /min from 5º to 90º
Fourier transform infrared spectroscopy (FTIR)
Spectrum Two IR Spectrometers, 20 scans
Thermogravimetric Analysis (TGA)
SDT Q600 V20.9 Build 20, 10.00 °C/min to 1000.00 °C
3. Results and Discussion
FTIR Results of PF with different viscosities
FTIR comparison of dried and liquid phenolic resins with different viscosities
OH Stretch
3389 cm-1
out of phase
stretching
vibration of
-CH2- alkane
C=C aromatic ring
C-H aliphatic
Asymmetric stretch
of phenolic C-C-OH
-NCO
indicates that
not all the
groups of MDI
have
completely
reacted.
FTIR of co-polymer system of MDI and PF resins with different molecular weights
With the increasing of PF’s molecular weights, the
–NCO groups becomes weaker which indicates that higher molecular
weights of PF resins can promote the reaction of MDI and PF resins.
FTIR of MDI/PF resins system and –NCO groups
Compared with the PF resins, some functions like the C=C
aromatic rings in the MDI/PF polymer appears while some
functions like isolated H in PF resins disappeared.
C=C
aromatic
ring
1633 cm-1
1513 cm-1
CH out-of-
plane,
isolated H
885 cm-1
Thermal properties3. Results and Discussion
There are two stages of the decomposition of MDI/PF polymer while there is
only one in the decomposition of PF resins. At the beginning of the
decomposition, the rate is much slower of co-polymer.
In the second
decomposition stage,
with the molecular weights
increasing, the rate
becomes slower and the
total weight loss rate
decreases. The co-polymer
of MDI+PF(W) shows the
best thermal property.
The first stage is the decomposition of MDI with the break of urethane bonds
and the second is the ester decomposition. And the second stage is much
slower than PF(M).
61.78% mass loss for the first stage and 37.81% mass loss for the second stage.
TG/DTG curve of MDI/PF(A)
TG/DTG curve of MDI/PF(M)
63.73% mass loss for the first stage and 30.52% mass loss for the second stage.
TG/DTG curve of MDI/PF(W)
56.76% mass loss for the first stage and 42.34% mass loss for the second stage.
Conclusions
Till the temperature of 320℃, the decomposition rate of
the co-polymer is much slower than PF resins
Beyond the temperature of 625℃, the rate of MDI/PF(w)
is the slowest and slower than PF resins.
The mass lost are almost the same.
MDI/PF(w) shows a better thermal property.
TEM analysis
3. Results and Discussion
TEM figures of MDI+PF(M) and PF(M)
Through TEM experiment, it is confirmed that both
MDI/PF and PF resins are amorphous material.
XRD analysis
3. Results and Discussion
XRD patterns of MDI/PF co-polymer and PF resins
There are crystalline peaks at about 30.5 and 34 2theta in all the XRD patterns of MDI/PF
co-polymer. The highest molecular weight leads to the highest the degree of crystallinity.
The crystalline peaks indicated that the co-polymer system of MDI/PF resins
has higher degree of crystallinity than PF resins in the structures.
XRD patterns of MDI+PF(M) co-polymer and PF(M) resins
4. Conclusions
According to FTIR analysis, higher molecular weights of
PF resins can promote the reaction of MDI and PF resins.
According to TG/DTG analysis, the co-polymer MDI and
the PF resins with the highest molecular weights has the
best thermal property.
The co-polymer system increase the degree of the
crystallinity and the highest molecular weights has the
highest degree.
5. Further study
Techniques of recycling isocyanate based polyurethane wastes
The main purpose of this study is to deal with millions of tons of isocyanate
based polyurethane wastes and get the raw materials for the co-polymer
system.
Mechanical property of co-polymer as wood adhesive
Conduct mechanical testing of isocyanate/phenolic resins copolymerization.
Wood structure design and adhesive application study for co-polymer
Proper wood panel structure design for this new-kind of wood resin.