Crystallization and Alkaline Degradation Behaviors of Poly(l-Lactide)/4-Armed Poly(ε-Caprolactone)-Block-Poly(d-Lactide) Blends with Different Poly(d-Lactide) Block Lengths

Dai, Suyang; Wang, Min; Zhuang, Zhiqiang; Ning, Zhenbo

doi:10.3390/polym12102195

Cited by 6 publications

(6 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From Figure 6a, the diffraction pattern of α-cellulose shows a characteristic broad peak area between 2θ values 20-40° which supports cellu- The crystallinity in α-cellulose, MCC, grafted α-cellulose, and grafted MCC were calculated to 27.1%, 39.5%, 46.7% and 60.6%, respectively. The crystallinity of PLLA was reported to 47.6% by Dai et al (2020) [53]. It is suggested here that the crystallinity of MCC is higher than that of α-cellulose.…”

Section: Waxs Analysismentioning

confidence: 66%

Grafting of Cellulose and Microcrystalline Cellulose with Oligo(L-lactic acid) by Polycondensation Reaction

et al. 2022

View full text Add to dashboard Cite

Oligo(L-lactic acid) (OLLA) was synthesized by ring opening polymerization of L-lactides using stannous octoate (0.03 wt% of lactide). While this served as the initiator, L-lactic acids were the co-initiators at 140 °C for 10 h, wherein L-lactic acids were prepared by hydrolytic degradation of L-lactides at 100 °C for 1 h. The molecular weight or degree of polymerization was controlled with monomer/co-initiator ratio (mol/mol). α-cellulose and microcrystalline cellulose (MCC) were extracted from jute fiber by subsequent treatment with sodium chlorite (Na2ClO2), NaOH and H2SO4. Grafting of OLLA onto α-cellulose and MCC in toluene was carried out using para-toluene sulphonic acid as a catalyst and potassium persulphate (KPS) as an initiator at 130 °C under 380 mm (Hg) pressure for 3, 6, 9, 12, 15, and 18 h. New properties of α-cellulose and MCC were observed due to the successful grafting onto α-cellulose and MCC. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) were conducted in order to confirm grafting of OLLA onto cellulose and MCC. The FTIR analysis results showed there are some new characteristic absorption peaks appeared (1728 to 1732 cm−1) in the spectrum, which confirmed the grafting of OLLA onto α-cellulose and MCC was successful. SEM images of α-cellulose and MCC before and after grafting revealed significant changes in surface morphology. Grafting of MCC could be more effective for further application in comparison to α-cellulose.

show abstract

Section: Waxs Analysismentioning

confidence: 66%

Grafting of Cellulose and Microcrystalline Cellulose with Oligo(L-lactic acid) by Polycondensation Reaction

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Hydrolysis roughened the surface of the fibers and caused cracks to form. Structural change occurred because of the cleavage of ester bonds in PLLA, which resulted in a lower mass of PLLA containing carboxyl and hydroxyl end groups. , Figure illustrates the weight loss during alkaline degradation for various types of PLLA fibers. The weight loss of all fibers increased monotonically with degradation time.…”

Section: Resultsmentioning

confidence: 99%

“…After 60 min, the FPLLA sample exhibited a weight loss of 58.8%. The degradation rate of PLLA fibers was considerably higher than those of bulk PLLA and its blends. − The rapid degradation of PLLA fibers was associated with a large interspace within the fiber mat, which allowed for easy penetration of water. This phenomenon subsequently increased the contact area of the water–PLLA interface, which resulted in the acceleration of PLLA degradation.…”

Section: Resultsmentioning

confidence: 99%

Additives for Enhancing the Crystallizability and Degradability of Electrospun Poly(l-lactide) Fibers

Lee,

2023

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

Poly(L-lactide) (PLLA) exhibits a low crystallization rate and a low degree of crystallinity, which limits its use in various applications. In this study, the effects of the addition of poly(ethylene glycol), poly(ethylene adipate), or phthalimide on the thermal and crystallization behaviors of electrospun PLLA fibers were investigated. The additives acted as plasticizers, decreasing the glass transition temperature of PLLA, which resulted in a substantial increase in its degree of crystallinity and a decrease in its crystallite size. Furthermore, the additives decreased the activation energy required for cold crystallization and, thus, increased the rate of cold crystallization kinetics. The various PLLA fibers formed α′ and α crystals, which consisted of loosely and closely packed chain organizations, respectively. During annealing, the α′ crystals gradually transformed into α crystals, and the additives accelerated this polymorphic transition. Furthermore, the presence of additives made the PLLA susceptible to alkaline degradation, which resulted in an increase in the degradation rate of the PLLA/additive fibers compared with that of neat PLLA fibers.

show abstract

“…Analysis shows that the melting temperature (Tm) of PCL blocks increases with the number of CL repetitive units per hydroxyl. The obtained multi-arm polymers are crystalline because the Tm value of the The research conducted by Z. Zhuang [178] focused on the crystallization mechanism of a mixture of a four-arm PCL-PLLA copolymer and a PLLA homopolymer showed that the variation of the PLLA length in this multi-arm structure has a significant effect on the crystallization state of the mixture and that the degradation behavior is closely related to the crystallization state of the mixtures. This highlights the ability of the multi-arm to alter the thermal properties of the entire mixture, not just the character of its own structure.…”

Section: Impact Of Multi-arm Topology On Pcl-based Polymer Properties...mentioning

confidence: 99%

Recent Advances in Nanoparticle Development for Drug Delivery: A Comprehensive Review of Polycaprolactone-Based Multi-Arm Architectures

et al. 2023

View full text Add to dashboard Cite

Controlled drug delivery is a crucial area of study for improving the targeted availability of drugs; several polymer systems have been applied for the formulation of drug delivery vehicles, including linear amphiphilic block copolymers, but with some limitations manifested in their ability to form only nanoaggregates such as polymersomes or vesicles within a narrow range of hydrophobic/hydrophilic balance, which can be problematic. For this, multi-arm architecture has emerged as an efficient alternative that overcame these challenges, with many interesting advantages such as reducing critical micellar concentrations, producing smaller particles, allowing for various functional compositions, and ensuring prolonged and continuous drug release. This review focuses on examining the key variables that influence the customization of multi-arm architecture assemblies based on polycaprolactone and their impact on drug loading and delivery. Specifically, this study focuses on the investigation of the structure–property relationships in these formulations, including the thermal properties presented by this architecture. Furthermore, this work will emphasize the importance of the type of architecture, chain topology, self-assembly parameters, and comparison between multi-arm structures and linear counterparts in relation to their impact on their performance as nanocarriers. By understanding these relationships, more effective multi-arm polymers can be designed with appropriate characteristics for their intended applications.

show abstract

Crystallization and Alkaline Degradation Behaviors of Poly(l-Lactide)/4-Armed Poly(ε-Caprolactone)-Block-Poly(d-Lactide) Blends with Different Poly(d-Lactide) Block Lengths

Cited by 6 publications

References 28 publications

Grafting of Cellulose and Microcrystalline Cellulose with Oligo(L-lactic acid) by Polycondensation Reaction

Grafting of Cellulose and Microcrystalline Cellulose with Oligo(L-lactic acid) by Polycondensation Reaction

Additives for Enhancing the Crystallizability and Degradability of Electrospun Poly(l-lactide) Fibers

Recent Advances in Nanoparticle Development for Drug Delivery: A Comprehensive Review of Polycaprolactone-Based Multi-Arm Architectures

Contact Info

Product

Resources

About