Authors present a poster dealing with the synthesis and characterization of Polylactic acid and Polyamide 11 with controlled macromolecular architecture

C.M. Yuan

E. Zini

G. Di Silvestro

H. Farina

L. Basilissi

L. Martino

M. Ortenzi

M. Scandola

AIR Universita degli studi di Milano

Polylactic acid and Polyamide 11 with controlled macromolecular architecture: 
synthesis and characterization
G. Di Silvestroa, M. Ortenzia, H. Farinaa, C.M. Yuana, L. Basilissia, E. Zinib, L. Martinob and M. Scandolab
a) University of Milan, Department of Organic and Industrial Chemistry, Via Venezian 21, 20133 Milan (Italy)
b) University of Bologna, Department of Industrial Chemistry, Viale del Risorgimento 4, 40135 Bologna (Italy)
Conclusions
Experimental PartThe interest towards environmentally friendly polymers has been
growing in the last decade and, especially in these last years, a
strong effort has been made to find adequate substitutes for
“traditional” oil-deriving polymers.
PLA and PA11 are two examples of polymers of this kind; they both
derive from renewable sources (PLA derives from corn or sugar and
PA11 derives from castor) and PLA is biodegradable according to
ASTM standard test.
PLA and PA11 present on the market are linear polymers and just a
few works are present about complex architecture PLA and PA11
obtained with bulk polymerization; in this work some samples were
synthesizes using different multifunctional comonomers in order to
modify macromolecular architecture.
PLA was obtained via bulk Ring Opening Polymerization (ROP) of
lactide at 190°C for 2 hours under nitrogen using Sn(Oct)2 as
catalyst.
PA11 was synthesized in bulk at 270°C for 4 hours under nitrogen
atmosphere.
Low quantities of different multifunctional comonomers were
directly added in the feed in order to obtain polymers with different
macromolecular architecture.
PLA/PA11 blends were prepared mixing different amount of the two
homopolymers.
---- PA 11+ AIA
---- PA 11+,BHT
---- Linear PA11
 Rheological curves show a marked dependence of viscosity on the quantity and nature of
the comonomers
 In PLA/PA11 blends nylon 11 crystals that form during rapid cooling in the press act as
heterogeneous nucleating agents that increase the speed of crystallization of PLA during the
DSC analysis.
 Blends obtained by hot mixing in which PLA is present only in the amorphous phase
behave like systems with good mechanical compatibility.
Using different type and amount of comonomers is
possible to change the melt behavior of PLA and
PA11.
Rheologic analyses demonstrate that as long as DPn
in star polymer is near the ones of linear polymers,
melt viscosity is far lower, but when a very high DPn is
obtained, melt viscosity significantly increases.
Branched polymer is more viscous than the linear one,
as expected.
---- PLA + 0.0625% TMP
---- PLA + 0.05% TMP
---- Linear PLA
---- PLA + 0.125% TMP
PLA present in blends is able to crystallize in
quantities much greater than PLA homopolymer.
Nylon 11 crystallizes both in blends than in
homopolymer with a considerable amounts of
enthalpy and its melting heat decreases with
increasing amounts of PLA .
The mechanical behavior of the two homopolymers is very different. The PLA has a strength value of
2.5% and breaks for deformation of about 10%. Nylon11 is much more ductile: the module is
approximately halved the strength value is much higher (εy = 35%) and the rupture occurs at
deformations higher than 100% . A curve very similar to that of Nylon 11, even if with less elongation
and higher elastic modulus is the blend containing 10% PLA. All other blends richer in PLA show a
brittle behavior and break before the yield point.


Polylactic acid and Polyamide 11 with controlled macromolecular architecture : synthesis and characterization

https://air.unimi.it/retrieve/handle/2434/254856/350027/2011%20-%20Terni%20-%20AIM%20-%20Poster%20-%20Polylactic%20acid%20and%20Polyamide%2011%20with%20controlled%20macromolecular%20architecture%20synthesis%20and%20characterization.pdf

Polylactic acid and Polyamide 11 with controlled macromolecular architecture : synthesis and characterization

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