China Visit us at : May 11, 2011

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L(+) LACTIC ACID POLYMERS AND COPOLYMERS :

2 nd Federation of Asian Polymer Fax : 0091

1 L(+) LACTIC ACID POLYMERS AND COPOLYMERS : STRUCTURE PROPERTY RELATIONSHIPS Dr. S. Sivaram National Chemical Laboratory, Pune , INDIA Tel : nd Federation of Asian Polymer Fax : Societies Polymer Congress, Beijing, s.sivaram@ncl.res.in China Visit us at : May 11, 2011

2 PLLA : MAJOR PROPERTY DEFICITS Slow rate of crystallization Very brittle material ; Elongation : 3-4 %, Poor heat stability Poor chain entanglement in melt state leading to poor melt viscosities CSIR Proprietary

3 PLLA PROPERTY IMPROVEMENTS : APPROACHES Poor rate of crystallization Annealing and cold crystallization Nucleation Poor Elongation Plasticization Copolymerization Increase Tm Stereocomplexation Copolymerization Nanocomposites and blends Increase melt viscosity Crosslinking Branching

4 SYNTHESIS OF POLY (L+) LACTIC ACID)S FROM L(+) LACTIC ACID

5 POLY(L+) (LACTIC ACID)S (PLLA) : PREPARATION L-Lactic acid Dehydro-polycondensation Poly(L-Lactic acid) oligomers Poly(L-Lactic acid) s Ring opening polymerization Depolymerization & cyclization L-lactide 95% yield, mp =94 o C Optical purity 100%

6 CRUDE L(+) LACTIDE FORMATION SUGAR CANE FERMENTATION OF SUGAR CANE JUICE TO L(+) LA ROP L(+) LACTIDE CRYSTALS L(+) LACTIDE CRYSTALLIZATION

7 LABORATORY POLYMERIZATION SET -UP Polycondensation set up doubled up to do distillation. SS reactor of 200mL / 800 ml. Electrical heating and overhead stirring. Ability to purge, pull vacuum, add additives. Nozzle at bottom to extrude polymer melt coupled with a pelletizer.

8 PREPARATION OF L(+) LA OLIGOMER VIA DEHYDRO- POLYCONDENSATION O Lactic acid : 600 g (90% aqueous solution) Conditions : 150 o C/N 2 /2h, 150 o C/100 mm, Hg/1.5h, 150 o C/30 mm, Hg/1.5h, 150 o C/0.005 mm, Hg/1h H O n OH Source Yield (%) Mn* (g/mol) Mw* (g/mol) PDI PURAC NCL * Determined by GPC in chloroform Under these conditions only linear oligomers are obtained with no cyclic oligomers ( MALDI-TOF)

9 PREPARATION OF DILACTIDE VIA DEPOLYMERIZATION AND CYCLIZATION) O O Lactic acid oligomer : 493 g; Catalyst : Tin powder (<150 µm) Conditions : 160 o C/N 2 /1h, 180 o C/100 mm, Hg/1h, 190 o C/10 mm, Hg/1h, 200 o C/0.01 mm, Hg/2h O O Expt. No. Tin Powder (wt%) LactideYield Optical Purity (%) (L+)(%) 1 ( >150 µm) 6 (>150 µm) L(+) LACTIDE AS FORMED UNSUITABLE FOR POLYMERIZATION: PURIFIED BY CRYSTALLIZATION FROM MELT :

10 PROTON NMR OF CRUDE L(+)LACTIDE PURIFICATION O NCL O O O PURAC O O O O

11 PROTON NMR OF CRYSTALLIZED L(+) LACTIDE NCL O O O O PURAC O O O O

12 PREPARATION OF POLY(LACTIC ACID)S via RING OPENING POLYMERIZATION Catalyst concentration: 0.03% to 0.05 wt% Chain stopper : Lauryl alcohol Temperature: 180 o C Expt. No. Chain Stopper (wt%) Time Mn a Mw a (min) (g/mol) (g/mol) PDI

13 ISOSORBIDE AS A COMONOMER

14 ISOSORBIDE MONOMER Dihydrohexitols - byproducts of biomass - prepared from starch, chiral in nature - thermally stable Monomer for biodegradable polymers - improved accessibility of two -OH groups - exo substituent increases ring thermal stability Polymers presented promising properties - high glass transitions - excellent thermal stabilities - interesting physical properties Isosorbide copolyesters - relatively high Tg s - cholesteric phase formation HO O H H O OH

15 ISOSORBIDE: A PLATFORM CHEMICAL

16 L(+) LA- ISOSORBIDE COPOLYMER Incorporation of isosorbide into PLLA by melt/solution disproportionation followed by solid state polymerization

17 L(+) LA-ISOSORBIDE COPOLYMER VIA MELT DISPROPORTIONATION PLLA : 10 g (IV : 1.6 dl/g; Mw: 160,000 g/mol) Catalyst : Titanium isopropoxide Catalyst conc.: 0.5 wt% (based on PLA) PLLA (wt%) Isosorbide (wt%) Temp. ( o C) Time (h) IV* (dl/g) * Determined in chloroform at 30 o C by Ubbelhode viscometer.

18 DISPROPORTIONATED L(+)LA-ISOSORBIDE COPOLYMER Sample ID PLA:ISB Ratio IV (dl/g) T m (ºC) T c (ºC) T g (ºC) H f (J/g) H c (J/g) PLAISB1 98: PLAISB2 94: PLAISB3 90: IV was determined in Chloroform at 30 o C by Ubbelhode viscometer Tg, Tm, Tc were determined by Q10 DSC (TA Instruments).

19 L(+) LA-ISOSORBIDE COPOLYMER VIA SOLUTION DISPROPORTIONATION PLLA : 10 g (IV : 1.6 dl/g; Mw: 160, 000 g/mol) Solvent : Chloroform Catalyst : Titanium isopropoxide Catalyst conc.: 0.5 wt% (based on PLA) PLLA (wt%) ISB (wt%) Temp. ( o C) Time (h) Incorp. (%) Yield (%) IV* (dl/g) * Determined in chloroform at 30 o C by Ubbelhode viscometer.

20 DISPROPORTIONATED L(+)LA-ISOSORBIDE COPOLYMER Sample ID PLA:ISB Ratio IV (dl/g) T m (ºC) T c (ºC) T g (ºC) H f (J/g) PLAISB4 90: PLAISB6 70: IV was determined in Chloroform at 30 o C by Ubbelhode viscometer Tg, Tm, Tc were determined by Q10 DSC (TA Instruments).

21 H NMR SPECTRA OF ISOSORBIDE IN CDCL Fig. 2

22 1 H NMR SPECTRA OF PLA-ISOSORBIDE COPOLYMER IN CDCL ,5 3,8 7, ,5 3,8 7, δ ppm

23 1 H NMR SPECTRA OF PLA-ISOSORBIDE COPOLYMER IN CDCL

24 SOLID STATE POLYMERIZATION OF DISPROPORTIONATED L(+) LA-ISOSORBIDE COPOLYMER Polymn Steps Sample ID IV (dl/g) T g ( C) T m ( C) T c ( C) H f (W/g) H c (W/g) 1 PLAISB BSSP 100 C/1h ASSP 120 C/2h ASSP 135 C/3h ASSP 145 C/2h ASSP 155 C/2h IV was determined in Chloroform at 30 o C by Ubbelhode viscometer Tg, Tm, Tc were determined by Q10 DSC (TA Instruments).

25 :DSC THERMOGRAMS OF PLA-ISOSORBIDE COPOLYMER DURING SSP Step-6 /g) Heat flow (W/ Step-5 Step-1 S tep-3 S tep Tem perature ( o C ) Fig. 9

26 12-HYDROXY STEARIC ACID AS COMONOMER

27 HO CH 3 O CH C OH + HO CH (CH 2 ) 11 COOH ( CH 2 ) 5 CH 3 O H O CH C O m CH 3 Sn Catalyst CH (CH 2 ) 11 ( CH 2 ) 5 O C OH n COPOLYMERS OF L (+) - LACTIC ACID WITH 12-HYDROXY STEARIC ACID CH 3

28 PROPERTIES OF L(+) LA 12- HSA COPOLYMERS mol% PLA mol% 12-HSA Feed Product T g ( C) T m ( C) M n (VPO) , , , NIL ,320

29 BRANCHING/CROSSLINKING USING STYRENE GMA COPOLYMER

SYNTHESIS OF STYRENE-GMA COPOLYMER Sty (%) GMA (%) IV a (dl/g) Mn b (g/mol) Mw b (g/mol) PDI Copolymer Comp c Sty (%) GMA (%) Epoxy eq d (g/mol) 30 70 0.14 6620 25820 3.90 40 60 203 40 60 0.

30 SYNTHESIS OF STYRENE-GMA COPOLYMER Sty (%) GMA (%) IV a (dl/g) Mn b (g/mol) Mw b (g/mol) PDI Copolymer Comp c Sty (%) GMA (%) Epoxy eq d (g/mol) a Determined by Ubbelhode viscometer in chloroform at 30 o C. b Determined by gel permeation chromatography using chloroform solvent. c Determined by 1 H NMR spectroscopy. d Determined by titrimetry.

31 MELT COMPOUNDING AND RHEOLOGICAL MEASUREMENTS Temp. : 180 o C, Residence Time : 3 min in nitrogen Speed : 100 rpm ARES RHEOMETER DSM MICROCOMPOUNDER

32 MELT COMPOUNDING OF STYRENE- GMA COPOLYMER WITH PLLA Polymer Code Sty:GMA (Comp.) PLA (%) St-GMA (%) Mn a (g/mol) Mw a (g/mol) PLLA PLLA :50 PLLA PLLA3 40: PLLA PLLA5 30: PLLA PLLA7 20: PLLA a Determined by gel permeation chromatography using chloroform solvent. PDI

33 STORAGE MODULUS AND COMPLEX VISCOSITY OF PLLA- GMA BLENDS Addition of 2 % GMA enhances melt viscosity of PLLA

34 SUMMARY Tm improved using isosorbide as comonomer Tg decreased using 12- hydroxystearic acid as comonomer Branching and crosslinking with S-GMA copolymer improves melt viscosity of PLLA

35 THANK YOU

36 SYNTHESIS OF PLLA OLIGOMERS CONTROLLED END GROUPS Controlled ROP of purified LL-dilactide performed 120 C/ 12 h H Oct 2 Sn O R O O O ROCO(CH 3 )OCOCH(CH H 3 )O SnOct 2 O R = H, WATER used as initiator to get carboxylic acid end groups M n = ([M] / [I]) x M Lactide x conversion % and DP n = ([M] / [I]) x conversion %

37 MOLECULAR WEIGHT DETERMIATION OF PLLA SAMPLES Number average molecular weights of the PLA oligomers synthesized by ROP of L-lactide with water as co-initiator and Sn(Oct) 2 as initiator. PLA sample [Lactide]/ [Sn(Oct) 2 ] [Lactide]/ [H 2 O] Conv. (%) DP n, Calc DP n, NMR M n, NMR M n, VPO Fig. 3.1: 13C-NMR spectrum (500 MHz) of PLLA oligomer3.1 synthesized by ROP : Inset showing ester carbonyl region (ester as well as carboxylic acid)

38 DSC OF PLA OLIGOMERS HAVING HYDROXYLA AND CARBOXY END GROUPS PLA samples T g ( C) T m ( C) H melt ing (J.g -1 ) % Crystallinity from powder XRD Fig. 3.2: Thermal characterization(dsc) first and second heating showing Tm and Tg, respectively of PLA oligomers: (a) 3.1, first heating; (b) 3.2, first heating; (c) 3.1, second heating and (d) 3.2, second heating

Figure S7: ATR FTIR spectra of enantiomeric UP-PLA-UPy and sc-upy-pla-upy. Figure S9: SEM microphotographs sc-upy-pla-oh in 1,4-dioxane and chloroform

Figure S7: ATR FTIR spectra of enantiomeric UP-PLA-UPy and sc-upy-pla-upy. Figure S9: SEM microphotographs sc-upy-pla-oh in 1,4-dioxane and chloroform Supporting Information for Macromolecules, DOI: Supramolecular Polylactides by the Cooperative Interaction of the End Groups and Stereocomplexation By M. Brzeziński*, T. Biela Table of Contents Figure