8/10/2019 Clay Polymer Properties

1/36

8/10/2019 Clay Polymer Properties

2/36

Intercalation vs.

Exfoliation

8/10/2019 Clay Polymer Properties

3/36

Intercalation vs.

ExfoliationTEM micrographs of

poly(styrene)-based

nanocomposites: (a) intercalated

nanocomposite and (b) exfoliated

nanocomposite.

8/10/2019 Clay Polymer Properties

4/36

Intercalation vs.

ExfoliationXRD patterns of: (a)

phase separated

microcomposite (b)

intercalated

nanocomposite and (c)

exfoliated

nanocomposite.

sin2d=

8/10/2019 Clay Polymer Properties

5/36

Mechanical Properties

Tensile Modulus

8/10/2019 Clay Polymer Properties

6/36

Eect of clay preparationSample

preparationiller

Content!"t #$

M% !&'()$ *oun+,s modulus!-Pa$

Commercialnylon ( ').( '.''

NCC 0 ').( '.(

NC1 2.3 '.) '.43

5NC1 0.) '6.3 7.(2

8nepotNC1 2.' 77. 7.70NCC9 montmorillonite:ased nylon microcomposite.NC19 nanocomposite o:tained :y in situ intercalative polymeri;ationof ecaprolactam in protonated aminododecanoic modi

8/10/2019 Clay Polymer Properties

7/36

Eect of aspect ratio

8/10/2019 Clay Polymer Properties

8/36

Nonlinear :ehavior

=Exfoliation

=!spect

ratio

8/10/2019 Clay Polymer Properties

9/36

Eect of layer char+e

density

8/10/2019 Clay Polymer Properties

10/36

Mechanical Properties

Tensile Stren+th

8/10/2019 Clay Polymer Properties

11/36

Eect of claymatrix

interfaceMatrix Matrix tensile

stren+thNano

8/10/2019 Clay Polymer Properties

12/36

Eect of Epoxy T+ In hi+h T+ epoxy thermoset@ neither intercalated

nor exfoliated nanosilicates lead to animprovement of the tensile stress at :reaA@ they

rather maAe the materials more :rittle. This eect appears to :e +enerally more

pronounced for intercalated structures than forexfoliated ones.

In contrast@ nanocomposites :ased on :oth epoxyand polyurethanes elastomeric matrices exhi:it asi;ea:le increase in tensile stress at :reaA uponthe addition of small Buantities of nano

8/10/2019 Clay Polymer Properties

13/36

Mechanical Properties

Elon+ation at :reaA

8/10/2019 Clay Polymer Properties

14/36

Eect of matrix Intercalated PMM> and PS or

intercalated exfoliated PP9 the

elon+ation at :reaA is reduced. Such a loss in ultimate elon+ation

does not occur in elastomeric

epoxy or polyol polyurethanematrices.

8/10/2019 Clay Polymer Properties

15/36

Eect of preparation

8/10/2019 Clay Polymer Properties

16/36

Eect of Exfoliation

8/10/2019 Clay Polymer Properties

17/36

Mechanical Properties

Impact

8/10/2019 Clay Polymer Properties

18/36

Eect of clay content

8/10/2019 Clay Polymer Properties

19/36

Clay/Naylon Timin+ :elt

-ood resistance to impact

a hi+h *oun+Ds modulus

+ood exural modulus

1i+her heat distortion temperature !from 0oC for pure

nylon to more than '0(oC for nanocomposites$

Feplace +lass

8/10/2019 Clay Polymer Properties

20/36

Mechanical Properties

HM>

8/10/2019 Clay Polymer Properties

21/36

Hynamic mechanicalanalysis

HM>9 measures the response of a +ivenmaterial to a cyclic deformation !usuallytension or threepoint exion type

deformation$ as a function of the temperature. HM> results9

the stora+e modulus !E,$@ correspondin+ to theelastic response to the deformation

the loss modulus !EJ$@ correspondin+ to the plastic

response to the deformation tan @ that is the !E,/EJ$ ratio@ useful for determinin+

the occurrence of molecular mo:ility transitions suchas the +lass transition temperature.

8/10/2019 Clay Polymer Properties

22/36

Temperat+re dependence of E, andtan

8/10/2019 Clay Polymer Properties

23/36

Eect of matrix

Trend of the

storage mod+l+s E,

at "$o for /-

based nano- and

micro-composite.

Nanocomposites

Microcomposites

8/10/2019 Clay Polymer Properties

24/36

Eect of matrix

PPCC9 microcomposite

8/10/2019 Clay Polymer Properties

25/36

Eect of clay preparation

8/10/2019 Clay Polymer Properties

26/36

HM> Summary

The stora+e elastic modulus appears to :esu:stantially enhanced at temperaturesa:ove T+ for exfoliated nanocomposites

8/10/2019 Clay Polymer Properties

27/36

8ther Properties

Thermal Sta:ility

8/10/2019 Clay Polymer Properties

28/36

>pproach

The thermal sta:ility of a material is usuallyassessed :y thermo+ravimetric analysis!T->$ "here the sample mass loss due to

volatili;ation of de+raded :yproducts ismonitored as a function of temperatureramp.

%hen the heatin+ is operated under an inert

+as o" !nitro+en@ helium@ . . .$@ a nonoxidative de+radation occurs "hile the useof air or oxy+en allo"s to follo" theoxidative de+radation of the sample.

8/10/2019 Clay Polymer Properties

29/36

Thermal sta:ility

T-> traces for PHMS

8/10/2019 Clay Polymer Properties

30/36

Eect of Clayloadin+/preparation

0-based nanocomposites

1ith di2erent clay

modi3cations

8/10/2019 Clay Polymer Properties

31/36

8ther Properties

lame Fetardancy

8/10/2019 Clay Polymer Properties

32/36

>pproach

Cone calorimetry9 the sample is exposedto a +iven heat ux !often taAen as )0A%/m7$ and the heat release rate !1FF$as "ell as the mass loss rate arerecorded as a function of time.

It is "orth notin+ that reduction of thepeaA 1FF is the most clearcut evidencefor the eKciency of a ame retardant.

Moreover@ +as and soot production arealso measured.

8/10/2019 Clay Polymer Properties

33/36

Eect of clay

8/10/2019 Clay Polymer Properties

34/36

8ther Properties

-as :arrier

8/10/2019 Clay Polymer Properties

35/36

C87 permea:ility of polyimideclay

0c and 0p:

composite

and the

+n3lled

polymer

permeability

8/10/2019 Clay Polymer Properties

36/36

Eect of exfoliation

!s the length of the clayincreases4 the relati5epermeability decreasesdrastically.

The best gas barrier properties1ill be obtained by f+llyexfoliated rather long layeredsilicates.