Chain Extender Content Research Articles

Improving the compatibility of polylactic acid/polycarbonate blends with nanoclay and Joncryl as chain extenders

AbstractThis study aimed to optimize the compatibility and performance of PLA/PC blends by investigating the effects of Cloisite 20A nanoclay (NC) and Joncryl chain extender (CE). PLA/PC blends with varying NC and CE loadings were prepared, and the optimal formulation was identified. The optimal NC and CE content were then used to produce PLA/PC blends with varying PC ratios. The test specimens were produced by mixing the mixture in a twin‐screw micro compounder and subsequent injection molding into dog bone specimens to investigate the thermal, mechanical, and morphological properties of the blends. Scanning electron microscopy and dynamic mechanical analysis confirmed the immiscibility of the unmodified blend, but significant improvements in blend morphology were observed with high NC/CE ratios. The presence of NC/CE resulted in reduced droplet size of dispersed PC phase and a new intermediate glass transition temperature (Tg) in DMA, suggesting partial miscibility. The highest thermal stability improvement was achieved with 5 wt% NC alone or a combination of 5 wt% NC and 1 wt% CE. Composites containing NC/CE showed the most significant improvements in composite properties, demonstrating their effectiveness as compatibilizers and improved compatibility in PLA/PC blends. These results indicate that the use of NC/CE is a promising method for expanding the applicability of PLA/PC blends.

Curing characteristics and performance of a bio-based polyurethane engineered sealant with high bonding strength: Effect of R value and chain extender content

Polyurethane (PU) engineering sealants can be used to fill construction joints and pavement cracks with excellent practical results. However, traditional engineering sealants have the disadvantages of poor strength and raw materials that are not environmentally friendly. In this paper, a novel composition system of bio-based polyurethane engineering sealant was developed. The effects of the isocyanate/macroglycol molar ratio (nNCO/nOH, R value) for component A and the contents of amine chain extender (AME) on the curing characteristics and properties of the PU sealant were investigated using a series of experiments. Firstly, the curing process of the sealant was studied by Fourier transform infrared spectroscopy (FTIR) test, surface drying time test and gel time experiments. Secondly, the basic physical properties of the sealant were studied by tensile and hardness tests. And the water resistance of the sealant was judged. Then, the characteristics of molecular movement of polyurethane sealant were analyzed by dynamic mechanical analysis (DMA). The tensile cross-sections of the specimens were observed by scanning electron microscopy (SEM). Finally, the thermal stability of sealants was studied by thermogravimetric (TG) analysis. The results indicated that the material developed in this research can be used as a high-performance engineering sealant in actual projects. The increase in the R value and the decrease in AME content resulted in a longer curing process of the sealant. The rise of R value and AME content was able to raise the tensile strength, bonding strength and hardness of the sealant. The water resistance of the sealant was better. Also, the glass transition temperature (Tg) and storage modulus could also be increased and the thermal stability of the previous stage could be reduced by increasing the R value and AME content. Considering both the performance and construction requirements, the optimum R value and AME contents are recommended to be 2.1 and 1.4%, respectively.

Recycling PET Bottles for 3D-Printing Filament: Effect of Chain Extender

This study investigates the effect of a chain extender on the properties of recycled polyethylene terephthalate (rPET) for 3D printing filament. The research focuses on the melt flow index (MFI), mechanical properties, thermal behavior, and crystallinity of rPET blends with varying chain extender concentrations. MFI analysis reveals that the viscosity of rPET is influenced by the grade and sources of the PET bottles. The addition of the chain extender decreases MFI, indicating increased viscosity. Mechanical testing shows a slight decrease in impact strength with increasing chain extender concentration, suggesting the presence of limitations or constraints within the material. Thermal analysis demonstrates that the chain extender elevates the glass transition temperature (Tg) and melting temperature (Tm) of rPET, indicating enhanced rigidity and thermal resistance. However, the crystallinity (Xc) decreases as the chain extender disrupts the regular packing of polymer chains within the crystalline regions. These findings provide valuable insights into the influence of the chain extender on the properties of rPET for 3D printing filament. The research contributes to the development of sustainable manufacturing practices and promotes the utilization of recycled materials in additive manufacturing applications, furthering the goals of the circular economy and environmental sustainability.

Influence of Epoxy Functional Chain-Extenders on the Thermal and Rheological Properties of Bio-Based Polyamide 10.10.

Bio-based polyamide 10.10 (PA 10.10) has excellent properties compared to other bio-based polymers such as polylactic acid (PLA) or polyhydroxyalkanoates (PHAs) and is therefore used in more technical applications where higher strength is required. For foam and filament extrusion, a good balance between strength and stiffness of the polymer is needed. Therefore, two commercial chain-extenders (Joncryl® ADR types) with different epoxy functionalities are used to modify the melt properties of PA 10.10. The chain-extenders are used in a concentration range up to 1.25 wt.%. The range of glass transition temperature widens with increasing Joncryl® content, and the apparent activation energy shows a maximum at a concentration of 0.5 wt.%. Furthermore, the melting temperatures are constant and the crystallinity decreases with increasing chain-extender content due to the formation of branches. During the second heating run, a bimodal melting peak appeared, consisting of α-triclinic and pseudo γ-hexagonal crystals. The weight average molar masses (Mw) measured by gel permeation chromatography (GPC) increased linearly with increasing ADR 4400 content. In contrast, the compounds containing ADR 4468 show a maximum at 0.5 wt.% and it begins to decrease thereafter. The rheological data show an increase in viscosity with increasing chain-extender content due to branch formation. ATR spectra of the compounds show a decrease at the wavelength of the primary (3301 cm-1) and secondary (1634 cm-1) (-NH stretching in PA 10.10) amine, indicating that chain-extension, e.g., branching, takes place during compounding.

Effect of chain extender content on tribological properties of polyurethane under water‐lubrication

AbstractPolyurethane has been extensively studied as a multifunctional material for water‐lubricated bearing materials. As one of the polyurethane elastomeric synthetic material, the content of 4,4′‐methylene bis(2‐chloroaniline) (MOCA) directly affects the intermolecular structure and thus the properties of the material. Five samples with different MOCA contents were prepared by casting molding and tested. The results showed that the optimal comprehensive performance was obtained when the ratio of the amino group to the hydrocyanic acid group was 0.95, with tensile, compressive, and bending strengths of 50.1, 91.8, and 12.6 MPa, respectively. Compared with other samples, the surface of the sample was smooth, which was conducive to the formation of the water film. The bearing capacity and lubrication condition are improved, and the best tribological performance was shown. This research for the application of polyurethane elastomer on the water‐lubricated bearing provides a theoretical basis.

Adsorption characteristics of amphiphilic open-cell poly(butylene succinate) foams with ultrahigh porosity

In this study, a CO2-assisted and environmentally friendly foaming approach was proposed to prepare amphiphilic open-cell poly(butylene succinate) (PBS)/glycerin monostearate (GMS)/chain extender (CE) foams with excellent adsorption capabilities and superhigh porosity. Compared with the torqued PBS foam, the hydrophilicity and cell stability of the PBS/GMS foam were markedly enhanced. With the gradual incorporation of CE, the crystallization temperature of diverse PBS/GMS/CE specimens increased from 79.2 °C to 92.1 °C, and their storage modulus rose by three orders of magnitude. When the CE content was 0.9 phr, the open-cell content of the PBS/GMS/CE3 foam reached 97.11 ± 0.67%. In addition, the adsorption capacity of PBS/GMS/CE3 foam was up to 34.33 ± 1.22 g/g for carbon tetrachloride, and its contact angle of water was 79.45°. To summarize, this study provided a promising strategy for fabricating multifunctional open-cell biodegradable polymer foams that could be applicable to wastewater treatment as well as filtration.

Compatibilized polylactide/polyamide 11 blends containing multiwall carbon nanotubes: Morphology, rheology, electrical and mechanical properties

The effect of adding multiwall carbon nanotubes (CNTs) on the morphology and properties of reactively compatibilized polylactide/polyamide 11 (PLA/PA11) blends with a 75/25 wt% composition was evaluated. The PLA/PA11 blends were compatibilized using an epoxy-based chain extender. The blends and nanocomposites were prepared using an internal mixer. The effects of the chain extender concentration, mixing strategy, PLA molecular weight and CNT concentration on the morphology were evaluated in light of rheological, electrical and mechanical characterization. Upon pre-mixing CNTs with PLA the morphology of the dispersed phase evolved to connected non-spherical, non-coalescing PA11 domains bridged by CNTs at the interface. A network-like structure was formed in the nanocomposites containing 2–3 wt% of nanoparticles characterized by a transition from liquid-to solid-like behavior. The electrical conductivity remained in the insulating range, largely due to inadequate interconnectivity of PA11-CNT domains. The nanocomposites based on the lower molecular weight PLA displayed larger relative increase of the electrical conductivity and Young modulus, compared to the neat blend, indicative of a better CNT dispersion and formation of a more interconnected PA11-CNT network.

Molecular dynamics simulation of molecular network structure and mechanical properties of polymer matrix in PBT propellant

3,3-Bis(azidomethyl)oxetane (BAMO)/tetrahydrofuran (THF) copolymer (PBT) constitutes the polymer matrix of PBT solid propellant and influences the mechanical properties of the propellant. In this work, the molecular network structure of the PBT propellant matrix was constructed by molecular dynamics method, the influence of different component contents on the mechanical properties was studied, and the structure - mechanical properties relationship at the molecular level was established. The simulation results showed that changes in the content of crosslinker (TMP) and chain extender (DEG) had slight effects on Young's modulus. The tensile strength of the polymer matrix network was positively correlated with the molecular chain length and the number of cross-linking sites formed by TMP. When the isocyanate index R was less than 1, increasing the content of TMP crosslinker led to low conversion rate due to insufficient curing agent, thereby reducing the number of cross-linking sites and the strength of the system. When the isocyanate index R was less than 0.87, the increase of DEG content increased the chain length of the main chain and strengthened the system. Due to the competitive reaction with the curing agent, the difunctional (-OH) chain extender monomer showed stronger reactivity than the trifunctional crosslinker monomer, and the excess chain extender reduced the number of crosslinking sites, destroyed the crosslinking network structure and reduced the strength.

Fabrication of Biodegradable Poly(Lactic Acid) Composites with High Toughness via In Situ Fibrillation Method and Facile Annealing Process

Elastomer-toughened biodegradable poly(lactic acid) (PLA) composites have been extensively studied; however, improving the toughening efficiency of elastomers with low costs while maintaining the biodegradability of composites remains challenging. In this work, biodegradable PLA/poly(propylene carbonate) polyurethane (PLA/PPCU) composites with high toughness were successfully prepared by the in situ fibrillation method followed by a facile annealing treatment. The chain extender (CE) was added to alter the viscosity ratio of the dispersed phase to the matrix, thereby tailoring dispersed phase morphology. PPCU fibers were observed when the CE content is greater than 0.5 wt %. Due to the increase in interfacial area, the impact strength increased from 5.1 ± 1.1 kJ/m2 for PLA/PPCU/CE blends with droplet-like dispersed phase morphology to 8.3 ± 1.0 kJ/m2 for PLA/PPCU/CE blends with fibrous dispersed phase morphology. Furthermore, when the CE content was 1.5 wt %, the impact strength of PLA/PPCU/CE blends increased sharply to 30.5 ± 3.9 kJ/m2 after a facile annealing treatment, which could be attributed to the greatly increased interfacial area and interfacial strength. This work provides a viable way to improve the toughness of PLA-based blends without sacrificing their degradability, which will facilitate the large-scale practical application of PLA.

Synthesis and Characterization of an Novel Intercalated Polyacrylamide/Clay Nanocomposite

Solving the problem of the low temperature and low salt resistances of conventional polyacrylamide and the high cost of functional monomers, and thus, introducing it to the interlayer space provided by a layered structure for polymer modification, is a promising option. In this study, montmorillonite was used as the inorganic clay mineral, and an intercalated polyacrylamide/clay nanocomposite was synthesized via in situ intercalation polymerization. The optimal synthesis conditions were a clay content of 10.7%, preparation temperature of 11 °C, initiator concentration of 2.5 × 10-4 mol/L, and chain extender concentration of 5%. The IR results showed that the polymer was successfully introduced to the nanocomposite. The synthesized intercalated polyacrylamide/clay nanocomposite exhibited a better thickening effect, good viscoelasticity, and better salt resistance and thermal stability than polyacrylamide. In addition, the thickening capacity and thermal stability were superior to the salt-resistant polymer, with a 16.0% higher thickening viscosity and a 15.1% higher viscosity retention rate at 85 °C for 60 d. The intercalated polyacrylamide/clay nanocomposite further expanded the application of polyacrylamide in petroleum exploitation.

Effect of nano‐sized zinc citrate on the supercritical carbon dioxide‐assisted extrusion foaming behavior of poly(lactic acid)

AbstractPoly(lactic acid) (PLA) foams containing various amounts of an epoxy as a chain extender (CE) and nano‐sized zinc citrate as a nucleating agent are prepared by continuous extrusion using supercritical CO2 (sc‐CO2) as a physical foaming agent. Processing parameters such as the CE content, sc‐CO2 flow rate, and foaming temperature are optimized with regard to the apparent density and expansion ratio of the PLA foams. The nano‐sized zinc citrate exhibits a high nucleation activity for the crystallization of the PLA. The addition of 0.5 wt% nano‐sized zinc citrate significantly increases the compressive strength and modulus of the PLA foams from 0.124 MPa and 3.1 MPa to 0.35 MPa and 19 MPa, respectively. The PLA/0.5 wt% nano‐sized zinc citrate foam shows a microcellular structure with an average cell diameter of 17.1 μm.

Effect of bio-based polyols and chain extender on the microphase separation structure, mechanical properties and morphology of rigid polyurethane foams

The preparation of polyurethane foams from bio-based polyols was a preferable alternative to save fossil resources, and the investigation of the microphase separation structure of foams can effectively guide their application. In this work, rigid polyurethane (PU) foams from three bio-based polyols and different content of chain extender of 1,4-butanediol were prepared. Microphase separation behavior and thermodynamic properties of the foams were analyzed by ATR-FTIR, SEM, TG, DSC and DMA. The hydrogen bond content increases and the microphase separation tendency is suppressed with the addition of bio-based polyols. The TG analysis reveals that the thermal loss of bio-based foams is earlier than that of petroleum-based foams at the initial stage. The hydrogen bond content of bio-based rigid PU foam derived from corn stalks increases by 6.03 % relative to petroleum-based foam, and the compression strength reaches 160.18 KPa. Furthermore, with the addition of 1,4-butanediol (5 wt%), the compression strength of bio-based rigid PU foam derived from corn stalks rises to 325.05 KPa, while the proportion of ordered hydrogen bonds is considerably higher than that of the original foam, demonstrating the increase in the degree of microphase separation.

Preparation and Self-Healing Application of Isocyanate Prepolymer Microcapsules

In this study, we successfully manufactured polyurethane microcapsules containing isocyanate prepolymer as a core material for self-healing protection coatings via interfacial polymerization of a commercial polyurethane curing agent (Bayer L-75) and 1,4-butanediol (BDO) as a chain extender in an emulsion solution. With an optical microscope (OM) and a scanning electron microscope (SEM), the resulting microcapsules showed a spherical shape and an ideal structure with a smooth surface. Fourier transform infrared spectra (FTIR) showed that the core material was successfully encapsulated. Thermal gravimetric analysis (TGA) showed that the initial evaporation temperature of the microcapsules was 270 °C. In addition, we examined the influence of the concentration of the emulsifier and chain extender on the structure and morphology of the microcapsules. The results indicate that the optimal parameters of the microcapsule are an emulsifier concentration of 7.5% and a chain extender concentration of 15.38%. Microcapsules were added to the epoxy resin coating to verify the coating’s self-healing performance by a surface scratch test, and the results showed that the cracks could heal in 24 h. Furthermore, the self-healing coating had excellent corrosion resistance.

Effect of chain extender on morphologies and properties of PBAT/PLA composites

Biodegradable poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA) composites were prepared by melt blending, and chain extender was used to improve the compatibility of PBAT/PLA blends through the chemical reaction. The influence of PLA and chain extender contents on mechanical properties, morphology, and rheological properties of PBAT/PLA composites was systematically investigated. The results revealed that the Young’s modulus and stress values gradually increased under the same strain, whereas the elongation at break decreased with the increase of chain extender content for PBAT/PLA (80/20) composites. Noteworthy, the presence of chain extender improves the interfacial compatibility between PLA and PBAT phases. At the chain extender content of 0.4, 0.6, and 0.8 wt.%, the extensional viscosity of the composites exhibited an increasing trend, whereas an obvious strain-hardening phenomenon emerged in the uniaxial extensional curves.

Main‐Side Chain Hydrogen Bonding‐Based Self‐Healable Polyurethane with Highly Stretchable, Excellent Mechanical Properties for Self‐Healing Acid–Base Resistant Coating

Developing an autonomous self-healing polyurethane (PU) elastomer with excellent mechanical properties and high ductility has attracted increasing attention. Nowadays, the synthesis of elastomers with excellent mechanical properties and rapid self-healing at room temperature faces a huge challenge. Herein, This work reports a new supramolecular PU with excellent mechanical properties and rapid self-healing at room temperature through the introduction of T-type chain extender into the supramolecular polymer chain. The introduction of T-chain extender can be used to enhance the mechanical strength of PU, and the multiple hydrogen bonds on the side-chain provide theoretical support for the rapid self-healing ability of PU. Maximum stress of the synthesized PU can reach 3.4 ± 0.15 Mpa, and maximum elongation at break can reach 3200% ± 160%. Due to flexibility and re-constructability of side-chain hydrogen bonds, PU stress repair efficiency can reach 96.7%, and can be self-healing scratches rapidly and effectively at room temperature. The mechanical properties and self-healing properties of PU can be adjusted by the content of T-type chain extender. The PU is applied to the metal surface coating, which has excellent acid-base resistance, bond strength up to 2.9 ± 0.1 Mpa, and the ability to eliminate local damage on the coating surface quickly at room temperature.

Thermal Stabilization of Recycled PET Through Chain Extension and Blending with PBT

This study investigates the effect of using a multifunctional epoxide chain extender (Joncryl® ADR 4468) on the thermal stabilization and rheological properties of recycled polyethylene terephthalate (R-PET) and its blends with polybutylene terephthalate (PBT). The R-PET samples were prepared without and with chain extender (CE) contents of 0.4 wt% and 0.8 wt%. R-PET/PBT blends with weight ratios of 75w/25w, 50w/50w and 25w/75w were also prepared without and with a given CE content of 0.2 wt%. The thermal stability of the melt blended samples was analyzed through small amplitude oscillatory shear (SAOS) rheological experiments. The structure of the samples was evaluated using a Fourier transform infrared (FTIR) spectrometer. While the dynamic rheological properties of R-PET were improved with the addition of Joncryl and by blending with PBT, during the SAOS rheological experiments, the complex viscosity of R-PET further increased due to the concurrent polycondensation of R-PET and the resumption of Joncryl reaction with R-PET molecules. These reactions during the rheological experiments were further expedited with increasing the testing temperature. On the other hand, in R-PET/PBT blends, the reactivity of Joncryl was more noticeable in blends with higher R-PET contents due to the higher available internal reactive sites of much shorter R-PET molecules. It was observed that the addition of only 0.2 wt% Joncryl to the blends of R-PET/PBT (75w/25w) dramatically improves the thermal stability and dynamic rheological properties of R-PET and most likely its processability.

Study on novel rosin‐based polyurethane reactive hot melt adhesive

AbstractChain extender is a major additive in polyurethane adhesive preparation, which has a great influence on its molecular weight, green strength, and thermal resistance. In this work, we first synthesized a novel rosin‐based chain extender to replace conventional petroleum derived ones due to rosin was a renewable and low cost natural material. Afterward, the as‐prepared rosin‐based chain extender reacted with the isocyanate‐terminated polyurethane prepolymer to prepare polyurethane reactive hot melt adhesive (PURHMA). Rosin contains rigid hydrophenanthrene ring, which may have good effect on the thermal and mechanical properties of PURHMA. Consequently, the characterization of the thermal and physical properties of sustainable PURHMA was made using differential scanning calorimetry, X‐ray diffraction, dynamic mechanical thermal analyzer, as well as thermogravimetric analysis. Eventually, the adhesion performance of PURHMA on wood substrates were investigated by adjusting the amount of rosin‐based chain extender in the adhesive system. It was found that with the increase of the chain extender content, the thermal resistance, mechanical property, and adhesion property of PURHMA were significantly improved. The tensile strength of adhesive joints increased from 4.15 to 15.53 MPa, and the ultimate lap shear strength increased from 5.76 to 8.92 MPa. More strikingly, the rosin‐based PURHMA exhibited excellent bonding strength even after aging in water (less than 18%).

Synthesis and degradation of 3D biodegradable polyurethane foam scaffolds based on poly (propylene fumarate) and poly[(R)-3-hydroxybutyrate

Tissue degeneration due to diseases, accidents, and wars is a worldwide issue. One of the methods used by regenerative medicine (RM) to aid tissue repair is by using a biodegradable tissue engineering scaffold (TES). Different body tissues have variable regeneration abilities, and hence, they require TES with variable degradation rates. This paper focuses on synthesising four polyurethane foam scaffolds (PUFS) with variable degradation rates based on the concentration of incorporated chain extender (CE) poly[(R)-3-hydroxybutyrate] (P3HB). The polyol employed is poly (propylene fumarate) (PPF) along with aliphatic 1,6-hexamethylene diisocyanate (HDI). GPC provided the molecular weight (Mn = 455.67 g mol−1, Mw = 587.15 g mol−1) and PDI (1.29) of the PPF. FTIR and 1H and 13C NMR confirmed the proposed structures (CC, COOR, and NHCOO) of the PUFS. The FESEM images revealed a bimodal pore structure, with random, irregular, interconnected pores (242–340 µm) and discrete void spaces (735–860 µm). The size of PUFS pores and void spaces (PU4 > PU3 > PU2 > PU1) is directly proportional to their respective degradation rates. The TGA/DTA curves show a decrease of an onset thermal decomposition temperature from PU1 to PU4 (267.17 ºC PU1, 267.28 ºC PU2, 256.01 ºC PU3 and 240.72 ºC PU4) due to the respective increase in CE concentration. The results of in-vitro degradation analysis at day 70, revealed significant difference between the weight loss (%) of each group (PU1 = 4.09 ± 0.18%, PU2 = 8.03 ± 0.17%, PU3 = 13.14 ± 0.12% and PU4 = 20.21 ± 0.19%). Thus, PUFS with a higher concentration of P3HB have a faster degradation rate due to the associated P3HB hydrolysable ester/-COOR functional group within the PUFS backbone. The chemical structure, bimodal morphology, and variable degradation rate of these PUFS could be employed for various RM applications.

Effect of multi-functional epoxy chain extender on the weathering resistance performance of Poly(butylene adipate-co-terephthalate) (PBAT)

In this research work, both natural weathering and artificial weathering processes were carried out to investigate the effects of multi-functional epoxy chain extender (Joncryl ADR 4370) content on the degradation and the mechanical properties and molecular weight of poly(butylene adipate-co-terephthalate) (PBAT). The carboxyl end-groups of PBAT decreased significantly with an increase in ADR content from 0 to 1.5 wt%. Similarly, the molecular weight of PBAT initially increased and then decreased because of the formation of a crosslinked network structure under the influence of excessive chain extenders. The main degradation mechanism of PBAT during the natural and artificial weathering process is photo-degradation and hydrolyzation. The degradation rate of PBAT increased with increasing content of chain extender, as hydroxyl groups facilitate the water attack on the ester bonds of PBAT. In contrast, the higher content of chain extender presented the lower loss velocity of the tensile strength. This is mainly because the more ADR content, the more crosslinking network structures will be formed during the melting extrusion which can slow down the decrease of tensile strength. Hence, it is indicated that the crosslinking structure has more effect on tensile strength than that of hydrolysis effect during degradation. According to the analysis and study on the performance changes of PBAT/ADR materials under the conditions of long-term natural weathering (360d) and artificial weathering (600 h), this work provides theoretical guidance to produce PBAT mulching films with excellent performance.

Effect of chain extender on morphology and tensile properties of poly(l-lactic acid)/poly(butylene succinate-co-l-lactate) blends

The effect of a multi-functional epoxy-based chain extender on the tensile properties of poly(l-lactic acid) (PLLA)/poly(butylene succinate-co-l-lactate) (PBSL) blends was investigated using X-ray diffraction, differential scanning calorimetry, attenuated total reflection infrared spectroscopy, solid-state nuclear magnetic resonance spectroscopy, and scanning electron microscopy. The PLLA/PBSL blend without the chain extender showed low strain at break because of its immiscible sea-island morphology. The chain extender reacted with both PLLA and PBSL during the blending process to produce three types of graft polymers. The graft polymer formed by the reaction of the chain extender with both PLLA and PBSL at the PLLA/PBSL interface improved the miscibility and tensile properties of the blend through interfacial interactions. The graft polymers connected with either PLLA or PBSL existed within the PLLA or PBSL domains, respectively and suppressed the molecular motions due to the intra-domain interactions. When 4 % chain extender was used, the miscibility of the blend improved and the suppressed molecular motions of the PBSL portion increased the maximum stress and strain at break. At the chain extender concentration of 6 %, the miscibility of the blends did not increase; however, the interfacial and intra-domain interactions increased, which deteriorated the tensile properties of the blends.