• Polyethylene/polypropylene (PE/PP): packaging waste• Polyolefins/polyethylene terephthalate (PO/PET): packaging waste• Polyolefins/polyamides (PO/PA): carpet waste• Polyolefins/acrylonitrile butadiene styrene (PO/ABS): automotive waste

Engineering Science

PLAST-I-COM - Compatibilization of polymer blendsMarianne Labet, Wim Thielemans

marianne.labet@kuleuven-kulak.be

Renewable Materials and Nanotechnology Research Group

BLENDS OF INTEREST• Literature review• Selection of potential candidates through chemical modelling• Chemical synthesis of candidates that are not commercially available• Formulation of the blends according to design of experiments (DoE)• Testing the properties of the blends• Comparison between calculation and experiments

THE EXAMPLE OF PE/PP BLENDS

PARTNERS FUNDING

Technologiecampus

Oostende

From the literature, one can see that EPM and EPDM rubbers are the main classes of compounds that have been used as compatibilizingagents for PE/PP blends. However, a wide variety of these are commercially available and no indication of the best composition to choose is given.

According to the group contribution theory, the best EPM is the one having 61 mol% ethylene (asindicated by a minimum in the curve ΔδEPM, PP/PE = f(Emol%) in fig. 1). Six EPMs close enough to thisdescription are commercially available.Similarly (see fig. 2), 10 commercially available EPDMs could be suitable.

group contribution theory

δt = δd = 15.921 (MJ.m-3)1/2

δp = δh = 0 (MJ.m-3)1/2

Chemical modelling

In addition, some non polymeric molecules have been identifiedas potential candidates. Among them, hentriacontane .

dotriacontane , nonylcyclohexane and

decylcyclohexane are commercially available.

Chemical synthesisSome molecules that are not commercially available but look promising have also been synthesized. These molecules have one PE-like moiety (a longunbranched chain) and a PP-like moiety (a long chain with short branches).

Formulation of the blends

Testing the properties of the blends

METHODOLOGY

Literature review

0.81

0.815

0.82

0.825

0.83

48 53 58 63 68

Δδ

EPM

, PE/

PP

[(M

J/m

3)1

/2]

ethylene content [mol%]

Fig. 1: Suitability of EPM as a candidate

to compatibilize PE/PP blends

Fig. 2: Suitability of EPDM as a candidate

to compatibilize PE/PP blends

suitability

available groups

-CH3

-CH<

-CH2-

>C<

=CH2

…

potential candidates …

13

13

Bertin & Robin, Eur. Pol. J. (2002) 38, 2255-2264Radonjič & Gubeljak, Macromol. Mater. Eng., (2002), 287, 122-132Penava et al., J. Elasomers & Plastics, (2012), 45, 391-403Ha et al., Pol. Adv. Tech, (1996), 7, 483-492

REFERENCES

Sch. 1: Esterification of

steaoryl chloride with phytol to

form phytyl stearate

Sch. 2: Etherification of

octadecyl bromide with phytol

to form octadecyl phytyl ether

PE

PPCandidate

Fig. 3: Formulation of the blends according to a DoE

( area of interest, • design points specific to each system, • design points that can be re-used across different systems)

Two PE (one HDPE, one LDPE) and two PP (one high molecular weight, one low molecular weight) will be tested.The blends will be formulated according to a DoE of mixture using the software Design Expert 9 (see fig. 3). This will allow usto cover the whole range of possible blends (from a small contamination of PE in a PP matrix to a small contamination of PP ina PE matrix) while limiting the number of experiments.Four points will be re-used for every candidate tested. Two points will be re-used for both PE. Two points will be re-used forboth PP. This will further reduce the number of experiments to carry out.

3

3

Tensile test Impact test SEMDMA

Several tests will be performed to determine the properties ofthe blends. The mechanical properties of the blends will beassessed by tensile and impact test. The glass transitiontemperature will be assessed by DMA. The size of the dispersedphase domains will be assessed by SEM.

force impact