Abstract
Atomic and molecular layer deposition techniques have
been successfully combined to produce inorganic-organic
hybrid films with properties derived from both the
inorganic and organic components. There are few reports
dealing with further converting of ALD/MLD thin films.
Typically inorganic oxide layers on polymer films in most
cases require an additional top layer to enable heat
sealing and to protect the thin film from mechanical
stresses and defects. Adhesion of low-density
polyethylene, polyethylene terephthalate and polylactic
acid on ALD Al2O3 have been tested previously, where good
adhesion was achieved in most cases only with the
low-density polyethylene. In this study we report
deposition of a hybrid ALD/MLD layer, its properties, as
well as its use as adhesion layer for polyactic acid
(PLA) extrusion coatings. A mixture of both lactic acid
optical isomers, D- and L-lactic acids, was used as MLD
precursor. 25 and 45 nm thick hybrid films were analyzed.
XPS analyses gave a quite similar composition for both of
these two coatings. FTIR analyses also indicated presence
and bonding of hybrid components. The oxygen to carbon
and oxygen to aluminum ratios were in line with
theoretical calculations for such a hybrid. Deposition
mechanism is expected to involve both hydroxyl groups of
the lactic acid. However, the results indicated also
other types of bonding between lactic acid and TMA or
between the lactic acid molecules. The thickness of the
hybrid remained the same for at least a week after the
deposition indicating certain level of stability. In next
step cellophane film deposited with 25 nm Al2O3 and 13 nm
TMA-lactic acid hybrid was used as a substrate for PLA
extrusion at different melt temperatures. Uncoated
cellophane and BOPLA were used as reference substrates.
PLA adhered only to itself and to the ALD/MLD hybrid with
peel strength values exceeding 100 N/m, while PLA did not
adhere to plain cellophane. Thickness of the MLD/ALD
hybrid on ALD Al2O3 layer had no obvious effect on the
adhesion properties at sealing temperature of 170 °C.
Original language | English |
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Publication status | Published - 2013 |
Event | 13th International Conference on Atomic Layer Deposition, ALD 2013 - San Diego, California, San Diego, United States Duration: 28 Jul 2013 → 31 Jul 2013 Conference number: 13 |
Conference
Conference | 13th International Conference on Atomic Layer Deposition, ALD 2013 |
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Abbreviated title | ALD 2013 |
Country/Territory | United States |
City | San Diego |
Period | 28/07/13 → 31/07/13 |
Keywords
- adhesion
- ALD
- hybrid
- lactic acid
- MLD
- PLA