Infrared and Raman studies on polylactide acid and polyethylene glycol-400 blend 4 PUBLICATIONS 0 CITATIONS SEE PROFILE 12 PUBLICATIONS 7 CITATIONS SEE PROFILE (original) (raw)
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Infrared and Raman studies on polylactide acid and polyethylene glycol-400 blend
As a biodegradableplastic, polylactideacid (PLA) can be blended with polyethylene glycol (PEG) to form a polymer blend because PEG has a good miscibility with PLA. Furthermore, this paper study the functional groups of PLA-PEG400 blend using direct casting to produce matrix film. Fourier Transform Infrared (FTIR) and Raman spectroscopy was used to identify alteration of functional group PLA-PEG400 blend. Absorbance and frequency wavenumber were used to observe any changing among functional group. In general, PLA-PEG blend did not produce a new configuration or chemical properties although some functional groups tended to decrease. PLA-PEG400 film spectra showed a similaritycompared to those of neat PLA because of each pristine polymer. However, FTIR and Raman investigated reducing carbonyl group of PLA with PEG400 addition and followed improving CH-COC bonding. Methyl group represented CH 3symmetric changed both the shift and absorbance.FTIR and Raman spectroscopy observed increasing hydrogen bonding with increasing PEG400 addition where a largest was found at PEG 10% and appeared at frequency range from 3400 cm -1 to 3600 cm -1 . According to PEG400 addition, a FTIR measuredenhancing crystalline region.
Polymers, 2020
In this study, different compatibilizing agents were used to analyze their influence on immiscible blends of polylactide (PLA) and biobased high-density polyethylene (bioPE) 80/20 (wt/wt). The compatibilizing agents used were polyethylene vinyl acetate (EVA) with a content of 33% of vinyl acetate, polyvinyl alcohol (PVA), and dicumyl peroxide (DPC). The influence of each compatibilizing agent on the mechanical, thermal, and microstructural properties of the PLA-bioPE blend was studied using different microscopic techniques (i.e., field emission electron microscopy (FESEM), transmission electron microscopy (TEM), and atomic force microscopy with PeakForce quantitative nanomechanical mapping (AFM-QNM)). Compatibilized PLA-bioPE blends showed an improvement in the ductile properties, with EVA being the compatibilizer that provided the highest elongation at break and the highest impact-absorbed energy (Charpy test). In addition, it was observed by means of the different microscopic tech...
Vibrational Spectroscopy, 2004
Infrared (IR) spectra were collected on a series of blends of poly(lactic acid) (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(3HB-co-3HHx) (3HHx ¼ 13:4 mol%)) using a single-bounce temperature-controlled attenuated-total-reflection (ATR) accessory with a diamond internal reflection element (IRE). Different approaches were used to analyze the raw spectral data, including peak positions, widths and intensities, principal components, and 2D correlation spectra. Differences in the interactions between the functional groups of the components become apparent as a function of temperature and composition. This study provides insights into the submolecular-level interactions and miscibility of this polymer blend system. In particular for the 40/60 PLA/P(3HB-co-3HHx) blend, two types of crystalline P(3HB-co-3HHx) C¼O bands were observed. The band representing a more-ordered local C¼O environment had a peak absorbance at a lower wavenumber than the second, less-ordered C¼O species. The 2D IR correlation analysis also revealed that the more-ordered material disappeared first upon heating of the sample and the amorphous P(3HB-co-3HHx) C¼O band formed before the less-ordered P(3HB-co-3HHx) C¼O band disappeared. This observation is likely the result of the less-ordered crystalline form being replenished by thermally induced disordering of the more-ordered crystalline form. Thus, the less-order crystalline material may be viewed as an intermediate form during the melting process. In the 80/20 PLA/P(3HB-co-3HHx) blend, it was observed that the lower wavenumber peak in the PLA C¼O doublet preferentially interacts with amorphous P(3HB-co-3HHx). When 10-20% P(3HB-co-3HHx) is added to PLA, the crystallinity of P(3HB-co-3HHx) is restricted, probably due to domain size restriction and inherent low nucleation density. These IR results suggest that P(3HB-co-3HHx) has the potential to increase the toughness of PLA dramatically, thereby enlarging the design space of sustainable materials achievable by blending. #
Polymer, 2006
ABSTRACT The structure, dispersibility, and crystallinity of poly(3-hydroxybutyrate) (PHB) and poly(l-lactic acid) (PLLA) blends are investigated by using Raman microspectroscopy. Four kinds of PHB/PLLA blends with a PLLA content of 20, 40, 60, and 80 wt% were prepared from chloroform solutions. Differences in the Raman microspectroscopic spectra between the spherulitic and nonspherulitic parts in the blends mainly lie in the CO stretching band and C–O–C and C–C skeletal stretching bands of PHB and PLLA. In addition to such bands, the Raman spectra of spherulitic structure in the blends show a band due to the CH3 asymmetric stretching mode at an unusually high frequency (3009 cm−1), suggesting the existence of a C–H⋯OC hydrogen bond of PHB in the spherulite. The existence of C–H⋯OC hydrogen bond is one of the unambiguous evidence for the crystallization of PHB component in the blends. Therefore, it is possible to distinguish Raman bands due to each component in the spectra of blends. Raman spectra of the spherulitic structure in the blends are similar to a Raman spectrum of pure crystalline PHB, while those of the nonspherulitic parts in the blends have each component peak of PHB and PLLA. The present study reveals that the PHB component is crystallized in the blends irrespective of the blend ratio, and that both components are mixed in the nonspherulite parts. The crystalline structure of PHB and the nonspherulitic parts of PLLA in the blends are characterized, respectively, by the unique band of C–H⋯OC hydrogen bond at 3009 cm−1 and CCO deformation bands near 400 cm−1.
Preparation and characterization of polyethylene glycol/poly(L-lactic acid) blends
Pure and Applied Chemistry, 2016
The effect of incorporation of poly(ethylene glycol) (PEG) on thermomechanical and hydrophilicity properties of poly(L-lactic acid) (PLLA) was investigated. PEG/PLLA blends, containing 10, 20, 30 and 40 wt% PEG, were prepared by melt-extrusion in a co-rotating twin-screw extruder. By DSC analysis, it was observed that the T g of PLLA phase in PEG/PLLA blends decreased accompanied by a significant decrease in T cc and increase in their melting enthalpy. Therefore, the addition of PEG enhances the crystallization ability of PLLA phase due to its lubricating effect which increased mobility of PLLA chains. From TGA it was observed that low concentrations of PEG (10 & 20 wt%) increase the T onset of thermal degradation, probably due to improved heat resistance of the crystalline phase. At higher PEG content, the T onset decreases, as the lubricating effect becomes the controlling mechanism for the initiation of degradation process. Decrease in tensile strength and modulus was recorded especially in PLLA blends with PEG content higher than 20 wt%. The elongation at break decreases reaching a maximum at 20 wt% PEG and then dropped again. To investigate the effect of PEG on the wetting ability of PLLA, water contact angle measurements were performed. The results indicate that the introduction of PEG lowers the contact angle values in PEG/PLLA film surfaces, as compared to pure PLLA, suggesting improved hydrophilic properties.
Journal of Applied Polymer Science, 2012
Polylactide (PLA) blends with 0-40 wt % gelatinized starches (GSs) in the presence of plasticizers and compatibilizer for improving interfacial bonding between two phases were prepared. The effects of compatibilizer, type and amount of starch, including type and concentration of plasticizer on the physical, morphological, thermal, and mechanical properties of these films were investigated. Two types of starch (corn and tapioca) were added as fillers, whereas the glycerol amount was varied from 0 to 35 wt % based on starch content. Polyethylene glycol (PEG400) and propylene glycol (PG) were added as plasticizers at four different amounts (5-20 wt %) based on PLA content, while methylenediphenyl diisocyanate was used as a compatibilizer at 1.25 wt % of GS. The results indicated that the presence of glycerol had no effect on the thermal degradation of GS. For PLA plasticization, the plasticized PLA with PEG400 had better properties than that with PG. Water absorption isotherm of the blend films increased as the amount of starches increased; in contrast, the tensile properties decreased progressively with the addition of the GS content. The blend films with gelatinized corn starch had higher tensile properties than those with gelatinized tapioca starch. V
ACS Applied Materials & Interfaces, 2012
Binary blends of two biodegradable polymers: polylactide (PLA), which has high modulus and strength but is brittle, and poly[(butylene succinate)-co-adipate] (PBSA), which is flexible and tough, were prepared through batch melt mixing. The PLA/PBSA compositions were 100/0, 90/10, 70/ 30, 60/40, 50/50, 40/60, 30/70, 10/90, and 0/100. Fouriertransform infrared measurements revealed the absence of any chemical interaction between the two polymers, resulting in a phase-separated morphology as shown by scanning electron microscopy (SEM). SEM micrographs showed that PLA-rich blends had smaller droplet sizes when compared to the PBSArich blends, which got smaller with the reduction in PBSA content due to the differences in their melt viscosities. The interfacial area of PBSA droplets per unit volume of the blend reached a maximum in the 70PLA/30PBSA blend. Thermal stability and mechanical properties were not only affected by the composition of the blend, but also by the interfacial area between the two polymers. Through differential scanning calorimetry, it was shown that molten PBSA enhanced crystallization of PLA while the stiff PLA hindered cold crystallization of PBSA. Optimal synergies of properties between the two polymers were found in the 70PLA/30PBSA blend because of the maximum specific interfacial area of the PBSA droplets.
Croatica Chemica Acta, 2004
Polymer blends of poly(D,L-lactic-co-glycolic acid), PDLLGA, and triblock polycaprolactone-poly(dimethylsiloxane)-polycaprolactone (PCL-PDMS-PCL) copolymer, TEGOMER, were obtained by coprecipitation from their chloroform mixed solutions into methanol and were characterized by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), degradation tests and scanning electron microscopy (SEM). Binary blends of PDLLGA/TEGOMER were found to be partially miscible according to DSC measurements and FTIR analysis. Stress-strain results showed that addition of TEGOMER improved significantly the overall toughness of PDLLGA. Degradation of PDLLGA/TEGOMER blends was investigated in phosphate buffered saline at pH = 7.4 and 37 °C, and the morphology of the blends during degradation was examined by scanning electron microscopy.
Indian Journal of Materials Science, 2013
The effects of hydrophilic nanoclay, Nanomer PGV, on mechanical properties of Polylactic Acid (PLA)/Polycaprolactone (PCL) blends were investigated and compared with hydrophobic clay, Montmorillonite K10. The PLA/PCL/clay composites were prepared by melt intercalation technique and the composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). FTIR spectra indicated that formation of hydrogen bond between hydrophilic clay with the matrix. XRD results show that shifting of basal spacing when clay incorporated into polymer matrix. TEM micrographs reveal the formation of agglomerate in the composites. Based on mechanical properties results, addition of clay Nanomer PGV significantly enhances the flexibility of PLA/PCL blends about 136.26%. TGA showed that the presence of clay improve thermal stability of blends. DMA show the addition of clay increase storage modulus and the presence of clay Nanomer PGV slightly shift two of blends become closer suggest that the presence of clay slightly compatibilizer the PLA/PCL blends. SEM micrographs revealed that presence of Nanomer PGV in blends influence the miscibility of the blends. The PLA/PCL blends become more homogeneous and consist of single phase morphology.
Journal of Applied Polymer Science, 2004
Thermoplastic polyethersulfone (PES) modified multifunctional tetraglycidyl-4,4 0-diaminodiphenylmethane (TGDDM) and triglycidyl para-aminophenol (TGAP) epoxy prepolymers cured with 4,4 0-diaminodiphenylsulfone (44DDS) were prepared using a continuous reactor method and their reaction-induced phase separated morphologies and mechanical properties were measured and correlated with chemical compositions. 1 H nuclear magnetic resonance (1 H NMR) and near-infrared spectroscopy (NIR) were used to quantify the chemical network formation. Atomic force microscopy (AFM) with nanomechanical mapping was employed to resolve the nanoscale phase-separated morphologies. The extent of phase separation in cured networks and resultant domain sizes were determined to be controllable depending upon the multifunctional epoxy compositions. The results obtained from mechanical studies further indicated that tensile modulus was not largely affected by multifunctional epoxy compositions while fracture toughness increased with increase of TGAP content.