Experimental set up

(1)

Experimental set up

Fig. S1 Incubation system during composting process

(2)

Thermogravimetric analysis: graphs and raw data

Fig. S2 TGA and DTGA graphs of MB at day 0, 20 and 60

Table S1 Characteristic temperatures and weight derived from TGA analysis, related to the peak of starch in MB

MB (starch)

0 20_1 20_2 20_3 60_1 60_2 60_3

T peak °C 317 305 302 303

%water 0 4 4 1 12 11 3

%residue 0 22 26 22 22 29 25

initial weight% 100 96 96 99 77 80 88

final weight% 70 80 78 81 76 81 87

(3)

Table S2 Characteristic temperatures and weight derived from TGA analysis, related to the peak of PBAT in MB

MB (PBAT)

0 20_1 20_2 20_3 60_1 60_2 60_3

T peak °C 395 397 395 397 395 395 395

%water 0 4 4 1 12 11 3

%residue 0 22 26 22 22 29 25

initial weight% 70 80 78 81 76 81 87

final weight% 4 24 28 24 22 32 32

weight % 66 56 50 57 54 49 55

weight loss % 15 24 14 18 26 17

Weight loss normalized on water % 15 23 14 16 23 16

Table S3 Example of calculation using Equations 2 and 3 (in the Manuscript) to extrapolate weight loss from TGA raw data. The example is made using values of MB(PBAT) day 60 reactor 1 (60_1), coloured in grey in Table 2.

Equation Calculation Result

Peak Area

PA (¿¿60)_PBAT(%)

∫

T0

Tinf

dw dT dT=¿

76 (%) – 22 (%) 54 (%)

Weight Loss*

PA PA

(¿¿0)_PBAT∗100=(WL^¿₆₀)_PBAT(%) (¿¿60)_PBAT

100−¿¿

100−54(%)

66(%)∗100 18 (%)

Weight Loss Normalized

on Water

WL^¿100−%water

100 =(W L₆₀)_PBAT(%) 18∗100−12

100 16 (%)

(4)

*This value needs to be normalized on water content

(5)

Fig. S3 TGA and DTGA graphs of PBAT at day 0, 20 and 60

Table S4 Characteristic temperatures and weight derived from TGA analysis, related to the peak of PBAT

PBAT

0 20_1 20_2 20_3 60_1 60_2 60_3

T peak °C 397 400 399 397 399 400 400

%water 0 0 0 0 1 1 1

%residue 0 7 11 12 10 11 10

initial weight% 100 100 99 99 99 99 99

final weight% 7 8 12 13 11 12 11

weight % 93 92 87 86 88 87 88

weight loss % 1 6 8 5 6 5

(6)

Fig. S4 TGA and DTGA graphs of PLA at day 0, 20 and 6

Table S5 Characteristic temperatures and weight derived from TGA analysis, related to the peak of PLA

PLA 0

20_

1 20_2 20_

3

60_

1 60_2 60_3

T peak °C 361 347 353 348 329 347 339

%water 0 3 1 2 3 1 2

%residue 0 0 0 0 1 1 4

initial weight% 100 97 99 98 97 99 98

final weight% 1 1 1 1 2 1 5

weight % 99 96 98 97 95 98 93

Weight normalized on water % 3 1 2 4 1 6

(7)

Fig. S5 TGA and DTGA graphs of LDPE at day 0, 20 and 6

Table S6 Characteristic temperatures and weight derived from TGA analysis, related to the peak of LDPE

LDPE

0 20_1 20_2 20_3 60_1 60_2 60_3

T peak °C 467 466 473 468 470 471 470

%water 0 0 0 0 0 0 0

%residue 0 0 0 0 5 0 1

initial weight% 100 100 100 100 100 100 100

final weight% 0 0 0 0 5 0 1

weight % 100 100 100 100 95 100 99

(8)

Scanning Electron Microscope

(9)

Experimental weight loss: raw data and further picture

Table S7 Experimental weight loss and adjustment in accordance with Equation 1 (in the Manuscript)

weight (g) not

adjusted adjustment weight (g) adjusted macro micro total water

(%)

residues (%)

Water + residues (%)

macro micro total

Weight loss adjusted (%) MB1 6,21 2,65 8,86 17 22 39 3,7881 1,6165 5,4046 45,954 MB2 5,48 2,89 8,37 15 29 44 3,0688 1,6184 4,6872 53,128

MB3 9,11 9,11 3 25 28 6,5592 0 6,5592 34,408

PLA1 9,4 0,9 10,3 3 1 4 9,024 0,864 9,888 1,12

PLA2 9,8 9,8 1 1 2 9,604 0 9,604 3,96

PLA3 9,7 0,62 10,32 2 4 6 9,118 0,5828 9,7008 2,992

PBAT1 10,6 10,6 1 10 11 9,434 0 9,434 5,66

PBAT2 10,5 10,5 1 11 12 9,24 0 9,24 7,6

PBAT3 9,9 9,9 1 10 11 8,811 0 8,811 11,89

LDPE1 10,2 10,2 0 5 5 9,69 0 9,69 3,1

LDPE2 9,7 9,7 0 0 0 9,7 0 9,7 3

LDPE3 10,5 10,5 0 1 1 10,395 0 10,395 -3,95