Functional Polymers From Renewable Resources：来自可再生资源的功能性聚合物

1、Functional Polymers From Renewable ResourcesS. Shang, A. Ro, S. J. Huang and R. A. WeissPolymer ProgramUniversity of ConnecticutStorrs, CTNew England Green Chemistry Consortium Annual MeetingUniversity of MaineOrno, MEMay 31, 2006Monomers From Renewable ResourcesPolymers based on renewable resources

2、 crops, grasses, agricultural byproducts Raw materials are sustainable; Polymers can be designed to be biodegradableLactic AcidItaconic AnhydrideStearyl MethacrylateFermentation of agricultural by-products (carbohydrates),e.g., corn starchPyrolysis of citric acid, orFermentation of carbohydrates to

3、form itaconic acid, followed by dehydrationDerived from fatty acid from animal or vegetable fats or oils Poly(lactic acid), PLADrumwright, R. E.; Gruber, P. R.; Henton, D. E. Adv. Mater. 2000. 12. 1841. Applications: Fibers, films, moldable thermoplastics (Tm 175C), suturesDeficiencies: Low Tg ( 60C

4、), Narrow melt processing window, Brittle plastic, hydrophobic; incompatible with other polymers (blends)IonomersPredominantly hydrophobic polymers that contain modest amounts of bonded acid or salt groups ( 15 mol%)Interchain association of salt groups significantly alters thermal properties, mecha

5、nical properties and rheology.PS1.82 NaSPS3.44 NaSPS5.81 NaSPSApplications: coatings, fibers, thermoplastics, adhesion promoters, compatibilizers, viscosifiers, permselective membranes, hydrogelsResearch GoalsSynthesize and Characterize Ionomers Derived from Lactic Acid, Itaconic Anhydride and Stear

6、yl MethacrylateRandom Ionomer- +- +- +- +Telechelic Ionomer- +- +- +ITASMITAITAPLAPLARadical copolymerizaton of ITA and SMIR evidence for copolymerizaiton: 1862, 1782 cm-1: ITA (anhydride) 5 member ring shift of C=O in SM from 1720 to 1731 cm-1 indicating reaction of C=C disappearance of peak at 160

7、1 cm-1: reaction of C=C1601MixtureCopolymerrITA = r1 = 0.53rSM = r2 = 0.12RandomCopolymersCopolymerization of ITA and SMMn (25k 60kDa) decreased with increasing fITAJ. Wallach, PhD Dissertation, Univ. Conn., 2000Thermal behavior of ITA-co-SM copolymersIncreasing SM compositionfITAMn (kDa)Tm (C)DH (J

8、/g SM)057.130.262.80.2945.131.283.00.4033.032.177.00.5334.844.787.90.540.4524.145.621.3Crystallinity is due to the SM side chain packingMelting temperature increased with increasing ITA content!Effect of ITA on crystallinity was complicated.No glass transition was observed (Tg(ITA) 130C)

9、.DSC: 1st scan after ppt from soln.Crystalline structure of ITA-co-SMComposition(mol% ITA)d (nm)02.9529.02.964552.83.983.1853.83.55100-Length of alkyl side chain = 2.5 nmSAXSWAXD0.417 nmcharacteristic of n-alkyl hexagonal packing,273.9 nmZn-Stearate Bilayer CrystalSide-Chain, Stearyl Methacrylate Cr

10、ystalsLLIntercalated CrystalBilayer CrystalL(Mn=33 kDa; 40 mol% ITA)IR evidence of neutralizationPeak 1550-1650 cm-1 due to COO- ITA-co-SM IonomersIonomer Structure and PropertiesIonic aggregation was observedLong spacing of SM crystals increased upon neutralizationNeutralization increased the elast

11、icity of the polymer.TMA (F = 60 mN)SAXSChemical Recycling of PLA by TransesterificationTransesterificationUncatalyzed - slow process, reaction temperature 250-300C. Catalyzed - lower time and temperature (J. Wallach, PhD Dissertation, Univ. Conn., 2000).SnOct2. FDA approved. MechanismSynthesis of -

12、carboxylate functionalized PLA Synthesis of methacrylate-terminated PLAB. Functionalization with itaconic anhydrideBroad OH stretchCarboxylic C=O stretchC-O-H in-plane bend and C-O stretchC=C stretchC=O stretchAsymmetric carboxylate anion stretch1H-NMR Spectrum of Functionalized PLA OligomerEnd grou

13、p Analysis -Mn = 1930, with 25 LLA units c dhdchFor higher molecular weight (M 15,000 900,000), Tg was relatively insensitive to functionalizationGlass Transition Temperatures of PLA-ITA Telechelic IonomersCations = Li+, Na+, K+, Ca2+, Zn2+, Y3+YZnCaLiNaKAcknowledgmentsFunding by:New England Green C

14、hemistry ConsortiumNSF/EPAPetroleum-Based PolymersHydrophobic and resistant to biodegradationEscalating prices of petroleum (only 2% of petroleum is used for polymers)*Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2003, U.S. Environmental Prote

15、ction Agency, 2003.Tullo, Chem. Eng. News. 2005, 83, 19.*Environmental ConcernsPlastic are the largest volume component in U.S. landfills ( 25%)Existing petroleum resources are limited.Plastics production has nearly doubled every 10 years for four decades.Environmental IssueSustainability IssueBiodegradable Polymers Aliphatic Polyesters from HydroxyacidsPoly(3-hydroxybutyric acid) Poly(lactic acid)NatureWorks LLCItaconic AnhydrideRamos PEG funct