8mofits of Srr use of siliconas in

Transcription

8mofits of Srr use of siliconas in
8mofits of Srr use of siliconas in
constr$Gtio$
$sitrses
All construction materiafs Er€ Exposadto damaging
envirsflm€nts rangrng from watpr ingression, to
abrasis{r by air-borne panieles, attack by organisms,
Silicone molecufe
. $tructural Goncrete
. Pawr#Flagstones
. Sandstone
. Limestsnelfttarble
'Bricks/file
.,Wood
For use eittrer as preventative or remedialtreatment
for
Fagade,OEM or Damp Proof Course {DPC}.
They pravida a variaty of benefrts:
.
.lmproved long term pratection
" Reducsd maintenanco time/costs
. Reduced efflorescence
. Reduced Spalling {keeze-thaw damage}
. Strengthening fragile rnasonry
. Reduced staining/easier cleaning
.0imensional stability sf wood
Through uniqua propenies af stlrcane
technology:
Brick treated wi*r Oorr0amnrgP Z-Ssl Water Repallent
taiiA
. ffepslleneyto water and oil, deponding on
ataehed grpups
. Permeableto water vapour
Concrete feated
wi*t 0ow Caminf Z-66S1Watsr Repallent
, Burable; chemically
reacts with substrate and
itself
.0eep penetrating; srnall molecular
. Low surface tensisn
. UV stable
r' \
size
l.l PerlomancG aspeot$ of silicones
E
.'.--- l'
h
>b
t5,=t
lAlood protected lirith Dow
bs
Carninf z-SBi[ Emulsion
Prstaction
Silicones are capable of penetrating and forming a
protective repellent layer several millimetres deep
within the substrate. with litde appreciable efiect on
$e water vapour trarismission rate $rcugh pores and
capillaries. As the depth oJ treatment is significant,
abrasion of the surface las liile or no effect on
performance. 0ther treatment$ to give repellency
block or seal only $e very top of these pores and
capiflaries. This resuhs in greater reductions of vapcur
transm ission, together with less abra sion resistance,
as the depth of protection is significantly less.
@protectionagainst
penetate deeply.
They chemically reactwith the substate and themselvasta pravida dwabilily pratectian, also
*ey allownoisfurc vapoyta pass.
figsro |
-
$rftcorye- based watar repellents when delivered to the surtace
effloresc'ence in limestone
It Pfrysical and Gftomical prcperties of
+hr
$ilieanes
{
rlqt
$ilieones are present in many forms and are often used
in combinetion to give the specifi c properties required
for effective trsatments.
l--.--......*,
-d
l,ffi
ra:i*
r
\"-
ro
--";#
RO
l.Ll
o*-o'
.Prx' *E
Silaner
$ilanes are the smallest silieone ensuring good
Depth of Penatratisn into substrates. They reactwi*r
themselves and any hydroxy {0H} groups within the
substrate vuhen mdisftre is prscent, forming a silicone
resin nswrrork. This formation of sffong cherftical
bonds provides fte durability attributed to siloxane
trsatmente
l#lpre B0 $ an aftorf g raup, typic ally methatq ar eth ary,
he oapabiliV n rea$ witlr hydrory WHI grsups on the
sg$strele
wtfrr
I
S an ugardr grsry$rctr as bwyt or aetyt fo gn€
Wtoplwbicity. Ta give ail repatlenoyl wauld cafiain
frasdne eontalining gtoufs
F.lrsrrengffienirgl'Hl
1-12 Polprors
W*er Eeading
$ilicone linear Bolymers are hellcal in shape, providing
a fot cf free space within their structnrefor individual
water vapour molecules to pass through, whilstwater
droplets are repelled bythe hydrophobic methyl
{CHr} graups nrhich orientate to the outside, giving
rupellency to liguid wate
-
droplee rspelled
hymffgroups
-,.s".JS
.€F
w
The low surfae e tension of the mefr$ groups enables
silicones to spread easily, forming a molecular layer
penetrating into the suhstrate.
.,'
Various groups can be subsdtuted onts the polymers
enabling chemieal reactivity with the substrate and
other silicone moleeules.
lf*arvapour
-
cffrpass$rough
the cpen silicona
$tructrre
Polynrers can be linear or cyclic, wi*r various groups
subetftuted intothe positions shown below.
*ts
nswrn:fe
lmins
Tfury
l$rstry|
lfteffi
A and B are substiurtsd groups.
S
Bt{
Aor
AorB
AY
AY
BY
f'l
Watsr repdlo*ey
Oil rnd Watsr
repellency
N
Gatalytic
X-lin*ing
X-lirking
X-linking
fietsrilnendatisns 0f suitability of prsdusts for use on
vsrlsus subsfates in the feflowing pass$ are based on
condderation of fie pofymsrtype and blend requlred
to achieve optimum performance.
Chemicalfu b'onded Intertace
I
-0 - EiI
I
-0-si
I
.0. tti
{
I
{i*
.
-0-si
II
-0. si
I
I
hmpregnrred reps$snt laysr st6silrats
$loud ot
ritilet fep6$€it
oFganis grcups