High-Performance Biodegradable PBAT/PPC Composite Film Through Reactive Compatibilizer

Poly(butylene adipate-co-terephthalate) (PBAT) is currently the largest commercial biodegradable plastics with good toughness and film forming properties, whereas, the inferior barrier and mechanical properties hinder its applications. Biodegradable poly(propylene carbonate) (PPC) with excellent barrier properties and high strength is a natural choice to address above issue. However, it is challenging to improve the compatibility of these two polymers. Herein, we prepared a reactive compatibilizer with double bond side group through terpolymerization of CO_(2)/propylene oxide/glycidyl methacrylate to enhance the properties of PBAT/PPC blends. Upon addition of 1 wt% compatibilizer, the PBAT/PPC blends (75/25, W/W) showed an increased water vapor barrier property changed from 424 g·m^(−2)·d^(−1) to 204 g·m^(−2)·d^(−1) compared to the control sample. Moreover, the tensile strength and elongation at break increased from 24.7 MPa to 30.3 MPa and from 858% to 1142%, respectively. The PBAT/PPC composite also displayed excellent biodegradability under composting conditions, as confirmed by the significantly decreased molecular weight. The present work provides an efficient way to barrier biodegradable film from PBAT of practical utilization.

Excellent Compatibilization Effect of a Dual Reactive Compatibilizer on the Immiscible MVQ/PP Blends

Methyl vinyl silicone rubber (MVQ)/polypropylene (PP) thermoplastic vulcanizate (TPV) combines the good melt processability, recyclability and sealing performance as well as biosafety, stain and fluid resistance, and thus it is especially suitable in bio-safety areas and wearable electronic devices, etc. Nevertheless, the compatibility between MVQ and PP phases is poor. A big challenge on the compatibilization of MVQ/PP blends is that neither MVQ nor PP contains any reactive groups. In this study, a dual reactive compatibilizer composed of ethylenemethyl acrylate-glycidyl methacrylate terpolymer (EMA-co-GMA) and maleic anhydride grafted polypropylene (PP-g-MAH) was designed for the compatibilization of MVQ/PP blends. During melt blending, a copolymer compatibilizer at the MVQ/PP interface can be formed because of the in situ reaction between EMA-co-GMA and PP-g-MAH. The thermodynamic predict of its compatibilization effect through calculating the spreading coefficient of the in situ formed copolymer indicates that it can well compatibilize MVQ/PP blends. The experimental results show that under the GMA/MAH molar ratio of 0.5/1, the interface thickness largely increase from 102 nm for non-compatibilized blend to 406 nm, and the average size of MVQ dispersed phase largely decreases from 2.3 µm to 0.36 µm, the Tg of the two phases shifts toward each other, the mixing torque and mechanical properties of the blend are increased, all indicating its good compatibilization effect. This study provides a good compatibilizing method for immiscible MVQ/PP blends with no reactive groups in both components for the preparation of high performance MVQ/PP TPVs.

Improvement in Toughness of Poly(ethyiene 2,5-furandicarboxyiate) by Melt Blending with Bio-based Polyamidel 1 in the Presence of a Reactive Compatibilizer

The objective of this study was to improve the toughness of bio based brittle poly(ethylene 2,5-furandicarboxylate)(PEF)by melt blending with bio based polyamide11(PA11)in the presence of a reactive multifunctional epoxy compatibilizer(Joncryl ADR-4368).The morphological,thermal,rheological,and mechanical properties of PEF/PA11 blends were investigated.Compared with neat PEF,the toughness of PEF/PA11 blend was not improved in the absence of the reactive compatibilizer due to the poor compatibility between the two polymers.When Joncryl was incorporated into PEF/PA11 blends,the interfacial tension between PEF and PA11 was obviously reduced,reflecting in the fine average particle size and narrow distribution of PA11 dispersed phase as observed by scanning electron microscopy(SEM).The complex viscosities of PEF/PA11 blends with Joncryl were much higher than that of PEF/PA11 blend,which could be ascribed to the formation of graft copolymers through the epoxy groups of Joncryl reacting with the end groups of PEF and PA11 molecular chains.Thus,the compatibility and interfacial adhesion between PEF and PA11 were greatly improved in the presence of Joncryl.The compatibilized PEF/PA11 blend with 1.5 phr Joncryl exhibited significantly improved elongation at break and unnotch impact strength with values of 90.1%and 30.3kJ/m2,respectively,compared with those of 3.6%and 3.8 kJ/m2 for neat PEF,respectively.This work provides an effective approach to improve the toughness of PEF which may expand its widespread application in packaging.

Influences of Hyperbranched Polyethylenimine on the Reactive Compatibilization of Polycarbonate/Polyamide Blends

The influences of hyperbranched polyethylenimine （hPEI）, which possesses many reactive amino end-groups, on the blending properties of bisphenol-A polycarbonate （PC） and amorphous polyamide （aPA） were systematically investigated. Scanning electron microscopy （SEM） and differential scanning calorimetry （DSC） were used to observe the effect of hPE1 on morphologies of PC and aPA phases in bulk blends. While the interfacial fracture toughness between planar PC and aPA layers with and without hPEI was studied by using augmented double cantilever beam （ADCB） method. Results show that the compatibility in PC/aPA blends can be significantly improved by adding a small amount of hPEI, mainly due to the interchange reactions between the polymers leading to the formation of block copolymers, cross-linked polymers and molecules with other constitutions. The augmented double cantilever beam experiments showed that the reactive process drastically reinforced the interfacial adhesion between planar layers of PC and aPA. However, degradation takes place during annealing at 180℃, which was responsible for the production of small molar mass species of PC.