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Characterization of Wood Polymer Nanocomposites Made of Melamine-Urea-Formaldehyde and Layered Silicate Clay Xiaolin Cai, Ph.D. FPInnovations – Forintek Bernard Riedl, Ph.D. University LavalPierre Blanchet, Ph.D. FPInnovations – Forintek Hui Wan, Ph.D. FPInnovations – Forintek Tony Zhang, Ph.D. FPInnovations – Forintek

Plan of Presentation

• Introduction

• Objectives

• Literature review

• Experimental and materials

• Results and discussion

• Conclusions

Introduction

• The shortage of high quality hardwood has driven researchers from academia and industry to modify low quality wood with different technical processes for value-added applications.

• Nanotechnology has been widely used and has achieved big success in polymer materials research and industry. Little work, however, has been done related to wood-polymer-nanocomposites.

• The main objective of this project is to evaluate the feasibility of preparing wood polymer nanocomposites with nano technique.

Objectives

•To prepare wood polymer nanocomposites (WPNC) with impregnation of prepolymer/nanofillers.

•To investigate the effect of in-situ reinforcement of prepolymer/nanofillers on mechanical/physical properties, water repellency, dimensional stability of the WPNC.

•To investigate the interaction of nanoparticles, polymer and wood.

• The basic technical processes

• The chemicals used in wood impregnation

• Polymer location in the wood

• Curing methods for wood polymer composites (WPC) preparation

II. Literature Review ⎯(i) Wood Impregnation

The Basic Technical Process

Basic TechnicalProcesses for Wood

Quality Improvement

Basic TechnicalProcesses for Wood

Quality Improvement

Chemical Impregnation (1960’s)

Chemical Impregnation (1960’s)

Chemical Impregnation And Compression

(Fry and Harry 1976)

Chemical Impregnation And Compression

(Fry and Harry 1976)

Compress Wood (1970’s)

Compress Wood (1970’s)

Chemical Using for ImpregnationChemical Using for Impregnation

Chemical Penetration in the Wood

Curing Methods

Microwave Heating Curing (Galperin et al. 1995)

Microwave Heating Curing (Galperin et al. 1995)

Radiation Curing (Ramalingam 1963,

Siau 1965, Meyer 1965)

Radiation Curing (Ramalingam 1963,

Siau 1965, Meyer 1965)

Catalyst – Heating Curing(Meyer 1965)

Catalyst – Heating Curing(Meyer 1965)

Radio-Frequency Heating (Beall et al. 1966)

Radio-Frequency Heating (Beall et al. 1966)

CURING METHODS FOR CHEMICAL

IMPREGNATION WPC

CURING METHODS FOR CHEMICAL

IMPREGNATION WPC

II. Literature Review (ii) Polymer/Nanocomposites

• The main reason that nanocomposites possess special properties not shared by conventional composites is the large interfacial area per unit volume of weight of the dispersed phase (e.g., 750m2/g) and high aspect ratio (>50). The literature of the polymer/nanocomposites include 2 parts:

• Structure of layered silicate clay

• Dispersion mechanism of silicate nanoclay

Structure of Layered Silicate

• Idealized structure of a montmorillonite layer showing two tetrahedral-site sheets fused to an octahedral-site sheet (2:1 type). [Qutubuddin and Fu 2002]

Process Challenge and Surface Modification Processing challenge for the

dispersion of nanoclayinto polymer

Model of clay Model of clay alkylammoniumalkylammonium--exchange by the monomer exchange by the monomer //prepolymerprepolymer

Experimental Design

Physical Properties of NanoclayClay Commercial code Organic modifier1 d-spacing2 Specific gravity Residue3 %

NF1 Cloisite® 30B MT2EtOH d001=18.5 Å 1.98 67.78±0.04

NF2 Claytone® APA R1R2R3R4N+Cl- d001=19.6 Å 1.70 60.97±0.27

NF3 Cloisite® Na None d001=11.7 Å 2.86 92.04±0.94

For better dispersion of nanoclay, ball milling nanoclay to exfoliate the powder to platelet was used. The figure shows the different d-spacing before and after ball milling nanoclay.(X. Cai et al. / Composites: Part A 39 (2008) 727–737)

1MT2EtOH: methyl, tallow, bis-2-hydroxyethyl, quaternary ammonium; R1 through R4 = combination of aliphatic chains, mthyl and (or benzyl groups), N=nitrogen. 2 X – Ray diffraction results d spacing3 thermal gravity analysis (TGA) from 30oC-1000oC, 20oC/min, air as protection gas. (X. Cai et al. / Composites: Part A 39 (2008) 727–737)

SEM and X-Ray composition analysis of nanoclay received and ball mill treated

SEM analysis of Cloisite 30B(Cai 2007) SEM analysis of ball milling Cloisite 30B(Cai 2007)

X-Ray composition analysis of Cloisite 30B (Cai 2007) X-Ray composition analysis of ball milling 30B (Cai 2007)

Transverse pictures of MUF, MUF/nanofiller treated wood

(a) Control Samples (b) MUF treated wood

(c)MUF/30B/wood (d)MUF/30B_bm/wood

(Cai et al. 2007, Wood and Fiber Sci.39, pp 307-318)

Trace of Nanoclay in the Wood by SEM

X-Ray composition analysis _ wood X-Ray composition analysis _ wood/MUF/APA

(a) (b) (c)

(X. Cai et al. / Composites: Part A 39 (2008) 727–737)

Electron Microprobe Analyze Element Distribution (CEMECA S×100, France)

Presence of Aluminum (Cai et al. 2007, Wood and Fiber Sci.39, pp 307-318)

MUF treated wood cell wall MUF/nanofiller treated wood cell wall

Transmission Electron Microscope (TEM) Analysis

(X. Cai et al. / Composites: Part A 39 (2008) 727–737)

Physical/Mechanical Properties Improvement

Hardness improvement by MUF/nanoclay Impregnation

0

1

2

3

4

MUF NF1 NF1_m NF2 NF2_m NF3 NF3_m contr

Har

dnes

s, M

Pa

Wear resistance index (100Wear resistance index (100--300300--500cycle)500cycle) of of MUF/MUF/nanoclaynanoclay treated or untreated aspentreated or untreated aspen

0

2

4

6

8

MUF NF1 NF1_m NF2 NF2_m NF3 NF3_m contr

Wea

r res

ista

nce

100cycle

300cycle

500cycle

Static Bending Properties of MUF/Nanoclay

0

2000

4000

6000

8000

10000

MUF NF1 NF1_m NF2 NF2_m NF3 NF3_mTreatment

MO

E, M

Pa

Treatmentcontrol

Water Repellency

0,0

20,0

40,0

60,0

80,0

100,0

MUF NF1 NF1_m NF2 NF2_m NF3 NF3_mtreatment

wat

er re

pelle

ncy

effic

ienc

y(W

RE

),% 1 day1 week

100/)((%) ×−= ctc WWWWRE

Anti-swelling efficiency (ASE) in tangential, radial direction and volume

of MUF-, MUF/nanoparticles-treated wood

0.0

20.0

40.0

60.0

MUF 30B 30B_bm APA APA_bm Na Na_bm

treatment

AS

E ta

ngen

tial,

%

0.0

20.0

40.0

60.0

AS

E ra

dial

, %

0.0

50.0

100.0

150.0

MUF 30B 30B_bm APA APA_bm Na Na_bmtreatment

AS

E in

vol

ume,

%

100/)((%) ×−= ctc SSSASE

Conclusions • Significant improvement in wood physical and mechanical properties was

obtained of the wood impregnated with MUF and nanoclay/MUF.

• The hardness of APA/MUF impregnated wood was improved from 1.09 MPa to 3.25 MPa.

• MOE of the treated wood is almost double of those untreated wood samples.

• A significant improvement in water repellency and better dimensional stability was obtained for the nanofiller/MUF treated wood.

• Antiswelling efficiency was improved from 63.3% to 125.6% for the nanofiller/MUF treated wood.

• The significant improvement in physical/mechanical properties, water resistance and dimensional stability of the resulting wood polymer nanocomposites could be attributed to the introduction of MUF and nanofillersinto the wood.

Reference

Xiaolin Cai, Bernard Riedl, S.Y. Zhang, Hui Wan, Formation and properties of nanocomposites made up fromsolid aspen wood, melamine-urea-formaldehyde, and clay Holzforschung, Vol. 61, pp. 148–154, 2007.

Xiaolin Cai, Bernard Riedl, S.Y. Zhang, Hui Wan, Effects of nanofillers on water resistance and dimensional stability of solidwood modified by melamine-urea-formaldehyde resin. Wood and Fiber Science, 39(2), 2007, pp. 307 – 318.

Xiaolin Cai, Bernard Riedl, S.Y. Zhang, Hui Wan. The impact of the nature of nanofillers on the performanceof wood polymer nanocomposites. Composites: Part A 39 (2008) 727–737

Xiaolin Cai, Thesis: Wood modification for value-added applications using nanotechnology-based approaches. 2007, Laval University.

Acknowledgements

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