Synthesis of Poly(lactide) Blends by Melt/Solid Polycondensation

Essawy, Hisham; Helaly, F. M.; Shabana, Mohamed A.

doi:10.1177/0095244307076498

Cited by 7 publications

(7 citation statements)

References 12 publications

(19 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It appears to be an attractive and promising route for PLLA synthesis due to its cost effectiveness which results from direct use of aqueous LLA other than L ‐lactide. However, it has not yet been industrialized up to now even though many efforts have been taken in the last decade, 8–20 mainly because its reaction rate is relatively low and thus very long reaction time is needed to reach high molecular weight.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of high molecular weight poly(L‐lactic acid) via melt/solid polycondensation: Intensification of dehydration and oligomerization during melt polycondensation

Song

2011

J of Applied Polymer Sci

View full text Add to dashboard Cite

Melt/solid state polycondensation (MP/ SSP) is a cost-effective route for synthesis of high molecular weight poly(L-lactic acid) (PLLA). However, the reaction rates in its four stages need to be enhanced greatly and the reaction times to be shortened largely before the MP/SSP technology can be industrialized. In this study, a new catalyst addition policy, i.e., adding TSA at the dehydration stage and SnCl 2 Á2H 2 O at the MP stage, and more appropriate temperature and pressure programs were presented and applied in the MP process of LLA. The presence of TSA from dehydration appeared very effective for speeding up the dehydration and oligomerization stages as well as depressing racemization in the whole MP process. The polymerization degree (X n ) of oligomer was clearly increased, and the reaction time was shortened to a great extent. Direct using reduced pressure was also very helpful for intensifying the dehydration stage, only leading to LLA loss as little as 2%. A PLLA with M w of 44,000 and optical purity of 96.8% suitable for subsequent SSP was produced after dehydration for 2 h, oligomerization for 2 h and MP for 4 h under appropriate conditions. And an interesting strong dependence of the M w of final PLLA product on the X n of the oligomer was observed.

show abstract

Section: Introductionmentioning

confidence: 99%

Synthesis of high molecular weight poly(L‐lactic acid) via melt/solid polycondensation: Intensification of dehydration and oligomerization during melt polycondensation

Song

2011

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…22 In the SSP of PLA, the PLA with relatively low molecular weight is heated up to a temperature between the glass transition temperature (T g ) and the melting temperature (T m ) for further polycondensation with the presence of proper catalysts. [31][32][33][34] During the polycondensation, the byproduct of the reaction is continuously removed from the surface of the material either by evaporation under reduced pressure or by driving it away by a carrier gas. As the reaction temperature of the SSP is relatively lower compared with melt polycondensation and solution polycondensation, the mobility of the end groups is slow and restricted.…”

Section: Polycondensation Of Plamentioning

confidence: 99%

Poly(lactic acid) fibers, yarns and fabrics: Manufacturing, properties and applications

Yang

Zhang

et al. 2020

Textile Research Journal

View full text Add to dashboard Cite

Poly(lactic acid) (PLA) fiber was developed more than a decade ago. It has been regarded as the most promising sustainable and biodegradable fiber to replace conventional polyethylene terephthalate (PET) polyester fiber in textile products. This paper reviews recent developments in PLA polymerization, PLA filament and fiber spinning, staple yarn spinning, fabric production, dyeing and finishing and aftercare procedures. The properties of PLA fiber are broadly similar to those of PET fiber; however, the properties of PLA fiber that differ, including thermal degradation and low hydrolytic resistance to strong alkaline, significantly affect the method selection and parameter setting of production and processing of PLA fibers and fabrics. PLA filaments are mainly produced by two-step melt spinning to get fibers with stable quality, but degradation at high temperature is still a problem. PLA staple yarns are normally spun using ring spinning. Currently existing knitting or weaving techniques can be used to produce PLA fabrics. PLA fabrics can be dyed with disperse dyes at 110°C, but their color fastness and shades are different from PET fabrics when using the same dyes. The scouring and dyeing of PLA/cotton blended fabrics and the reductive clearing after dyeing remain to be improved. As a new fiber, the entry of PLA fiber into the textile market faces difficult challenges as well as great opportunities in the future.

show abstract

“…Nunez et al [32] 15 Rajan et al [36,37] 16. Ternary blend of PLA, liquid natural rubber Bijarimi et al [38] was prepared by Essawy and group [39] . The preparation was carried out in one step by melt/solid polycondensation.…”

Section: Preparationmentioning

confidence: 99%

Polyblends and composites of poly (lactic acid) (PLA): a review on the state of the art

Rajan¹,

Thomas²,

Gopanna³

et al. 2018

J. Polym. Sci. Eng.

View full text Add to dashboard Cite

Polymers obtained from renewable sources are gaining popularity over their petroleum based counter parts in recent years due to their capability to address the environmental pollution related concerns emanating from the widespread usage of synthetic polymers. Even though the polymers from renewable sources are attractive in an environmental point of view, some of the property limitations and the high cost of these materials pose limitations for their extensive commercial applications. These aspects opened the door for a large chunk of research activities in development of polyblends and composites containing polymers from renewable sources as one of the components. Poly (lactic acid) (PLA) is one of the most discussed and commercialized polymer originated from renewable resources. Even though it has many useful properties, certain disadvantages like high brittleness, low impact resistance etc. limit the wide spread commercialization of PLA. In this review article, the recent research activities which are aimed to fill this gap by various modifications of PLA are discussed with special emphasis on the latest research advancements in the field of biodegradable and non biodegradable systems containing PLA.

show abstract

Synthesis of Poly(lactide) Blends by Melt/Solid Polycondensation

Cited by 7 publications

References 12 publications

Synthesis of high molecular weight poly(L‐lactic acid) via melt/solid polycondensation: Intensification of dehydration and oligomerization during melt polycondensation

Synthesis of high molecular weight poly(L‐lactic acid) via melt/solid polycondensation: Intensification of dehydration and oligomerization during melt polycondensation

Poly(lactic acid) fibers, yarns and fabrics: Manufacturing, properties and applications

Polyblends and composites of poly (lactic acid) (PLA): a review on the state of the art

Contact Info

Product

Resources

About