Development of clay nanofillers for plasticised PVC

Transcription

1 Development of clay nanofillers for plasticised PVC Marianne Gilbert and Xiaoran Zheng, IPTME, Loughborough University, Loughborough, Leicestershire, LE11 3TU

2 Lecture outline Introduction Experimental Results and Discussion Cloisite Na Cloisite 10A Cloisite 30B Phosphonium modified clay Conclusions

3 Aim To develop viable formulations and establish whether nanocomposites provide a useful route for restricting migration of monomeric plasticisers

4 Experimental - formulations Screening test phr Main Investigations PVC SH PVC SH DIDP 50 DIDP 50 Stabiliser Interlite ZP9600(Ca/Zn) 3 Lankromark LZB968 (Ba/Zn) Tinstab BTS71N (Tin) phr Tinstab BTS71N 1.5 Co-stabiliser Lankroflex E2307 0, 1.5, 3 Lankroflex E Stearic acid 0.1 Stearic acid 0.1 Cloisite Na 5 wt% Nanoclay wt% 0, 2, 5,10

5 Experimental -processing Dry Blending - Fielder/Henschel Melt processing Mill/Haake Torque rheometer Compression moulding at 185 o C

6 Experimental - characterisation Oven testing at 190 o C Dynamic stability in Haake Rheometer Transmission Electron Microscopy (TEM) Wide angle X-ray diffraction Thermogravimetric Analysis (TGA)

7 Schematic diagram of montmorillonite Cloisite Na nm

8 Effect of stabilizers on dynamic stability of Cloisite Na plasticised PVC at 190 o C; 80rpm Tor que ( Nm) Runni ng Ti me ( mi n) Ba/ Zn Co Ca/ Zn Co Ti n Ti n Co

9 Effect of Na clay loading on dynamic stability of Ca/Zn and Sn stabilised compounds 48 Ti me t o Degr adat i on ( mi n) Ti n Co Ca/ Zn Co Cl ay Concent r at i on ( wt %)

10 Blend A B C D E F Mixing Procedure Add all solid materials in the beginning (1st step), then all liquids when temperature reached 80 o C (2nd step). Add NaMMT at 2nd step together with all liquids. Premix NaMMT and DIDP; add paste at 2nd step. Premix NaMMT, DIDP and co-stabilizer; add paste at 2nd step. Premix NaMMT, DIDP, co-stabilizer and tin stabilizer; add paste at 2nd step. Add all materials except DIDP, heat up to 110 o C, cool down the blends, repeat process twice. Add DIDP in the final cycle, and allow the blend to reach 120 o C.

11 X-ray diffraction traces for samples produced using various mixing procedures NaMMT Intensity E D C B A F PVC- P Thet a

12 TEM images of PVC/DIDP/ Cloisite Na samples Sample C Sample F

13 Oven ageing of Cloisite Na based compounds with various stabilisers at 190 o C

14 Cloisite 10A HT is hydrogenated tallow (~65% C 18 ; ~30% C 16 ; ~5% C 14 ; anion chloride)

15 X-ray diffraction traces for Cloisite 10A Intensity Theta 10A PVC-10A PVC-P

16 TEM images of PVC/DIDP/ Cloisite 10A milled samples 50nm

17 Effect of nanoclays on dynamic stability in Haake torque rheometer at 190 o C; 80rpm PVC- P Tor que ( Nm) PVC-P/Cloisite Na PVC-P/Cloisite 30B PVC-P/Cloisite 10A PVC- P/ washed Cl oi si t e 10A Ti me ( mi n)

18 EDAX analysis of Cloisite 10A before and after washing Weight ratios Cloisite 10A before washing Cloisite 10A after washing C/Si O/Si Al/Si Cl/Si

19 Cloisite 30B T is tallow (~65% C 18 ; ~30% C 16 ; ~5% C 14 ; anion chloride)

20 Cloisite 30B compounds aged at 190 o C

21 X-ray diffraction traces for Cloisite B compounds Intensity 30B PVC-30B (5%) PVC-30B (3%) PVC-30B (1%) PVC-P Theta

22 TEM images with 5% Cloisite 30B Scale bar (a) 500nm; (b) 50nm (a) (b)

23 Migration data for various plasticisers 7 Weight % migration DOP DOP-Na DIDP DIDP-Na DIDP 30B TOTM TOTM-Na Time (day)

24 Development of phosphonium surfactant modified clays Intensity Thet a Benzyl - PMMT Hydr oxyet hyl - PMMT Al l yl - PMMT Pent yl - PMMT Pr opyl - PMMT Met hy- PMMT Cloisite Na Ion exchange with Na + successful (P present in clay) Intergallery spacing increased Should be less reactive with chlorine in PVC

25 Effect of phosphonium modified clays on dynamic stability of plasticised PVC at 190 o C Torque (Nm) Blank Methyl PMMT Propyl PMMT Pentyl PMMT Hydroxyethyl PMMT Benzyl PMMT Allyl PMMT Cloisite 30B Cloisite 10A Time (min)

26 TGA traces of phosphonium modified clays Wei ght % Temper at ur e( ) Cl oi si t e Na Met hyl - PMMT Pr opyl - PMMT Pent yl - PMMT Hydr oxyet hyl - PMMT Benzyl - PMMT Allyl-PMMT Cl oi si t e 10A

27 Conclusions PVC-P Cloisite Na compounds can be produced with adequate stability Intercalation/ exfoliation can be increased by changing dry blending conditions, but is still inadequate Cloisite 10A provides reasonable filler dispersion but very poor thermal stability. This can be improved by washing the clay Cloisite 30B provides reasonable filler dispersion and better thermal stability. Cloisite 30B produces a small reduction in plasticiser migration The modification of Cloisite Na with phosphonium compounds increases intergallery spacing and the fillers are more stable than ammonium modified clays