Characterization of Polymerization of Isocyanate Resin and Phenolic Resins … · 2016. 11. 22. ·...

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.