Stereocomplex Crystallization Induced Significant Improvement in Transparency and Stiffness–Toughness Performance of Core‐Shell Rubber Nanoparticles Toughened Poly(l‐lactide) Blends

Abstract

Toughening modification of poly(l‐lactide) (PLLA) with rubber particles is often realized at the cost of transparency, mechanical strength, and modulus because high rubber loadings are generally required for toughening. In this work, a promising strategy to simultaneously improve the transparency and stiffness–toughness performance of poly(butyl acrylate)‐poly(methyl methacrylate) (BAMMA) core‐shell rubber nanoparticles toughened PLLA blends by utilizing the stereocomplex (SC) crystallization between PLLA and poly(d‐lactide) (PDLA) is devised. The results reveal that the construction of SC crystallites in PLLA matrix via melt‐mixing PLLA/BAMMA blends with PDLA can prevent BAMMA nanoparticles from aggregation and promote them to form network‐like structure at lower contents. As a result, not only higher toughening efficiency with less rubber contents but also superior transparency is achieved in the PLLA/PDLA/BAMMA blends as compared with the PLLA/BAMMA ones where large aggregated BAMMA clusters are formed. Moreover, the outstanding reinforcement of SC crystallites network for PLLA can impart an enhanced tensile strength and modulus to PLLA/PDLA/BAMMA blends, thus improving the stiffness–toughness performance of PLLA/PDLA/BAMMA blends to a higher degree. This work demonstrates that SC crystallization is a promising solution to solve the contradiction between transparency and mechanical properties and then obtain superior comprehensive performances in rubber toughened PLLA blends.

Manipulating Matrix Crystallization and Impact Toughness of Polylactide/Elastomer Blends via Tailoring Size and Packing Density of Stereocomplex Crystallites Formed at the Interface

“…[24][25][26][27][28][29][30][31] Stereocomplex (SC) crystallites, formed by co-crystallization between PLLA and poly(D-lactide) (PDLA) in a side-by-side way, have been recognized as an efficient and environment-friendly nucleator for PLLA crystallization. [32][33][34][35][36][37][38][39][40][41][42][43] Distinctly different from PLLA homocrystallites, the higher melting temperature (≈60 °C) enables SC crystallites to remain un-melted state and then provide heterogeneous nucleation sites. In our previous works, [40][41][42] we have succeeded in fabricating super-toughened and heatresistant PLLA blends by melt-blending with PDLA grafted elastomers, where numerous SC crystallites are in situ formed at the blend interface through stereocomplexation between PLLA and PDLA segments.…”

Effect of Entanglement Density on Mechanical Properties and the Deformation Mechanism of Rubber‐Modified PPO/PS Blends

“…[6][7][8][9][10][11] Researchers have explored the toughening mechanism of rubber to obtain a method to control the toughening effect of rubber and achieve the balance of stiffness and toughness in materials. [2,[12][13][14][15] An effective method for analyzing the toughening mechanism was to observe the internal morphology of the fracture surface and judge the deformation mechanism of the material.…”

Simultaneously Toughening and Reinforcing Polylactide by Regulating the Distribution of Core–Shell Rubber Particles with Carbon Black

“…[24][25][26][27][28] There has been a lot of research into utilizing CSR particles to toughen PLA recently. [28][29][30][31][32] Satisfactory toughening effect can be often achieved by adding 15-25 wt% CSR, but the significant deterioration in strength and modulus of PLA always takes place simultaneously. [32][33][34][35] Even in the case that the PMMA component content in CSR tougheners is high enough, the strength and modulus losses are still very obvious.…”