Shulin Sun

Bio: Shulin Sun is an academic researcher from Changchun University. The author has contributed to research in topics: Compatibilization & Copolymer. The author has an hindex of 17, co-authored 73 publications receiving 722 citations. Previous affiliations of Shulin Sun include Chinese Academy of Sciences.

Polylactide toughening with epoxy-functionalized grafted acrylonitrile–butadiene–styrene particles

Abstract: Glycidyl methacrylate functionalized acrylonitrile–butadiene–styrene (ABS-g-GMA) particles were prepared and used to toughen polylactide (PLA). The characteristic absorption at 1728 cm−1 of the Fourier transform infrared spectra indicated that glycidyl methacrylate (GMA) was grafted onto the polybutadiene phase of acrylonitrile–butadiene–styrene (ABS). Chemical reactions analysis indicated that compatibilization and crosslinking reactions took place simultaneously between the epoxy groups of ABS-g-GMA and the end carboxyl or hydroxyl groups of PLA and that the increase of GMA content improved the reaction degree. Scanning electron microscopy results showed that 1 wt % GMA was sufficient to satisfy the compatibilization and that ABS-g-GMA particles with 1 wt % GMA dispersed in PLA uniformly. A further increase of GMA content induced the agglomeration of ABS-g-GMA particles because of crosslinking reactions. Dynamic mechanical analysis testing showed that the miscibility between PLA and ABS improved with the introduction of GMA onto ABS particles because of compatibilization reactions. The storage modulus decreased for the PLA blends with increasing GMA content. The decrease in the storage modulus was due to the chemical reactions in the PLA/ABS-g-GMA blends, which improved the viscosity and decreased the crystallization of PLA. A notched impact strength of 540 J/m was achieved for the PLA/ABS-g-GMA blend with 1 wt % GMA, which was 27 times than the impact strength of pure PLA, and a further increase in the GMA content in the ABS-g-GMA particles was not beneficial to the toughness improvement. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Effect of Miscibility and Crystallization on the Mechanical Properties and Transparency of PVDF/PMMA Blends

Abstract: Poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA) were blended over the whole range of composition. DMA and SEM results indicated PVDF and PMMA were miscible. Mechanical properties showed when PMMA content was lower than 40%, the yield strength decreased and the elongation at break increased with the PMMA content. The PVDF/PMMA blend showed the lowest yield strength and the highest elongation at break which were 24 MPa and 762% respectively when PMMA content was 40%. The crystallization of PVDF decreased transmittance of the blends due to light scattering between the interface of crystal and amorphous phase when PMMA was as matrix.

Enhanced properties of poly(lactic acid) with silica nanoparticles

Abstract: The objective of this article is to fabricate poly(lactic acid) (PLA) and nano silica (SiO2) composites and investigate effect of SiO2 on the properties of PLA composites. Surface-grafting modification was used in this study by grafting 3-Glycidoxypropyltrimethoxysilane (KH-560) onto the surface of silica nanoparticles. The surface-grafting reaction was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Then the hydrophilic silica nanoparticles became hydrophobic and dispersed homogeneously in PLA matrix. Scanning electron microscope and Dynamic thermomechanical analysis (DMA) results revealed that the compatibility between PLA and SiO2 was improved. Differential scanning calorimetry and polarized optical microscope tests showed that nano-silica had a good effect on crystallization of PLA. The transparency analysis showed an increase in transparency of PLA, which had great benefit for the application of PLA. The thermal stability, fire resistance, and mechanical properties were also enhanced because of the addition of nano silica particles. Copyright © 2016 John Wiley & Sons, Ltd.

Perspective on Polylactic Acid (PLA) based Sustainable Materials for Durable Applications: Focus on Toughness and Heat Resistance

Abstract: Evolution of the bioplastics industry has changed directions dramatically since the early 1990s. The latest generation is moving toward durable bioplastics having high biobased content. The main objective is to replace “fossil carbon” with “renewable carbon”, a holistic strategy to mitigate climate change by minimizing the environmental impact of a product throughout its life cycle. Durable bioplastics is desired for multiuse long-term application in automotive, electronics and other industries. One necessary requirement for them is to be both tough and strong, yet the two attributes are often mutually exclusive. Does this mean a biobased and biodegradable polymer as polylactic acid (PLA) with its high strength but low toughness cannot be adopted for durable applications? Well, not exactly; this is where the concept of tailoring the properties of PLA to achieve stiffness–toughness balance along with acceptable heat resistance comes into play. In this perspective, we summarize the recent research progress ...

Properties and medical applications of polylactic acid: A review

Abstract: Polylactic acid (PLA), one of the well-known biodegradable polyesters, has been studied extensively for tissue engineering and drug delivery systems, and it was also used widely in human medicine. A new method to synthesize PLA (ring-opening polymerization), which allowed the economical production of a high molecular weight PLA polymer, broad- ened its applications, and this processing would be a potential substitute for petroleum-based products. This review described the principles of the polymerization reactions of PLA and, then, outlined the various materials properties affect- ing the performance of PLA polymer, such as rheological, mechanical, thermal, and barrier properties as well as the pro- cessing technologies which were used to fabricate products based on PLA. In addition, the biodegradation processes of products which were shaped from PLA were discussed and reviewed. The potential applications of PLA in the medical fields, such as tissue engineering, wound management, drugs delivery, and orthopedic devices, were also highlighted.