PLLA Microalloys Versus PLLA Nanoalloys: Preparation, Morphologies, and Properties

Dong, Wenyong; Jiang, Fanhui; Zhao, Liping; You, Jichun; Cao, Xin; Li, Yongjin

doi:10.1021/am3007577

Cited by 74 publications

(90 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, PLA shows brittleness and poor toughness, which limits its usage for applications that require a complete range of mechanical behavior, especially ductility . The melt mixing of the PLA with flexible polymers is the most widespread and economic technique for overcoming its mechanical limitations .…”

Section: Introductionmentioning

confidence: 99%

Effect of the Chemical Structure of Compatibilizers on the Thermal, Mechanical and Morphological Properties of Immiscible PLA/PCL Blends

Finotti

Costa²,

Chinelatto³

2016

Macromolecular Symposia

View full text Add to dashboard Cite

Summary This manuscript addresses the effect of the chemical structure of two block copolymers of low molecular weight employed as compatibilizers on the immiscible blends of poly(lactic acid) (PLA) and poly(ϵ‐caprolactone) (PCL). Binary and ternary blends were prepared by melt mixing in a twin screw extruder and the effect of the block copolymers on the morphological, mechanical and thermal behavior was investigated by scanning electron microscopy (SEM), tensile testing and differential scanning calorimetry (DSC). The addition of 5 wt% of block copolymers derived from ϵ‐caprolactone and 1,4 butanediol (C1) or ϵ‐caprolactone and an aliphatic polycarbonate (C2) maintained the size of the dispersed PCL domains practically constant, regardless of the PCL concentration. The compatibilized PLA/PCL blends containing 5 wt% of PCL exhibited a significant enhancement in elongation at break, in comparison to those of the neat PLA or uncompatibilized PLA/PCL blends. The DSC results show the melting temperatures of the PLA were not influenced by the chemical structure of the compatibilizers or PCL concentration. However, such variables changed the melting enthalpy of the PLA and PCL and melting temperature of the PCL.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of the Chemical Structure of Compatibilizers on the Thermal, Mechanical and Morphological Properties of Immiscible PLA/PCL Blends

Finotti

Costa²,

Chinelatto³

2016

Macromolecular Symposia

View full text Add to dashboard Cite

show abstract

“…13, 14 To obtain toughened products, extensive studies have been carried on PLLA blends with other soft polymers because it is more versatile and economic to blend PLLA with other polymers than chemical modification. 15,16 Previously, several blend systems containing PLLA have been investigated, such as PLLA/poly(ε-caprolactone) (PCL), 17−20 PLLA/poly(ethylene oxide) (PEO), 21 PLLA/poly(butylenes succinate) (PBS), 22 PLLA/poly(butadiene-co-acrylonitrile) (NBR), 23 PLLA/polyurethane. 24 However, most of these blends are immiscible and compatibilizers are needed to improve their compatibility and reinforce the interface.…”

Section: Introductionmentioning

confidence: 99%

Miscibility and Double Glass Transition Temperature Depression of Poly(l-lactic acid) (PLLA)/Poly(oxymethylene) (POM) Blends

et al. 2013

Self Cite

View full text Add to dashboard Cite

The poly(L-lactic acid)/poly(oxymethylene) (PLLA/POM) blends have been prepared by simply melt blending. The phase diagram, miscibility, glass transition temperatures, and physical properties have been investigated systematically. The PLLA/POM blends exhibit typical lower critical solution temperature (LCST) behaviors. PLLA and POM are miscible in the melt state at low temperature and become phase-separated at elevated temperatures. It was found that the weak interactions between the carboxyl groups of PLLA and methylene groups of POM (weak C−H ... O hydrogen bonding) account for the miscibility of the two components. Although the PLLA/POM blends are homogeneous at the melt state in the miscible temperature region, two distinct glass transition temperatures are observed for the all blends when quenched from the homogeneous state. More surprisingly, both POM and PLLA exhibit the apparent glass transition temperature (T g ) depression in the blends, compared with T g s of the neat polymers. The behaviors are totally different from other reported miscible or partially miscible polymer blends, in which T g s shift to each other or merge into one glass transition temperature. The investigation indicates that the crystallization of POM in the blend induces the phase separation of PLLA/POM blends and forms novel morphologies with the interpenetrated (cocontinuous) PLLA and POM phases. The double glass transition temperature depression of both PLLA and POM in the blends originates from the mismatch thermal shrinkage during cooling down from the high temperature. Moreover, we observed the improved ductility of the PLLA/POM blends as compared with the neat PLLA and POM, which has been attributed to higher molecular mobility due to the glass transition temperature depression for both PLLA and POM in the blends.

show abstract

“…In order to overcome these limitations, the use of plasticizers, blends, copolymerization, micro and nanocomposites have been investigated [6][7][8][9][10][11]. It has been shown that these modifications result in PLA based materials with improved elongation at break, impact strength, toughness and barrier properties.…”

Section: Introductionmentioning

confidence: 99%

Maintaining Structural Stability of Poly(lactic acid): Effects of Multifunctional Epoxy based Reactive Oligomers

et al. 2014

View full text Add to dashboard Cite

Abstract:In order to reduce the effects of hydrolytic degradation and to maintain sufficient viscosity during processing of biomass based poly(L-lactic acid) (PLLA), various epoxy functional reactive oligomers have been characterized and incorporated into the degraded fragments as chain extenders. The molecular weight of PLLA increased with the increase in functionality of the reactive oligomers. No further increase in molecular weight was observed for oligomers with functionality of greater than five. Under our experimental conditions, no gelation was found even when the highest functionality reactive oligomers were used. This is attributed to the preferential reaction of the carboxylic acid versus the negligible reactivity of the hydroxyl groups, present at the two ends of the degraded PLLA chains, with the epoxy groups. The study provides a clear understanding of the degradation and chain extension reaction of poly(lactic acid) (PLA) with epoxy functional reactive oligomers. It is also shown that a higher functionality and concentration of the reactive oligomers is needed, to bring about a sufficient increase in the molecular weight and hence the hydrolytic stability in circumstances when PLA chains suffer significant degradation during processing.

show abstract

PLLA Microalloys Versus PLLA Nanoalloys: Preparation, Morphologies, and Properties

Cited by 74 publications

References 52 publications

Effect of the Chemical Structure of Compatibilizers on the Thermal, Mechanical and Morphological Properties of Immiscible PLA/PCL Blends

Effect of the Chemical Structure of Compatibilizers on the Thermal, Mechanical and Morphological Properties of Immiscible PLA/PCL Blends

Miscibility and Double Glass Transition Temperature Depression of Poly(l-lactic acid) (PLLA)/Poly(oxymethylene) (POM) Blends

Maintaining Structural Stability of Poly(lactic acid): Effects of Multifunctional Epoxy based Reactive Oligomers

Contact Info

Product

Resources

About