OMMT对PHBV/EVA共混物的改性研究

以有机改性蒙脱土（OMMT）为改性剂，采用熔融共混法制备了聚（3-羟基丁酸酯-co-3-羟基戊酸酯）/乙烯-乙酸乙烯酯/有机改性蒙脱土（PHBV/EVA/OMMT）共混物和样条，并通过旋转流变仪、差示扫描量热仪（DSC）、红外光谱仪（FTIR）、万能试验机、热失重分析仪（TG）、偏光显微镜（PLM）和扫描电子显微镜（SEM）等对其流变性能、结晶性能、力学性能、热性能及微观形貌等进行了表征。结果表明，随着OMMT含量的增加，PHBV/EVA/OMMT共混物的损耗模量和复数黏度增大；在PHBV/EVA/OMMT共混物中，OMMT产生了插层结构；OMMT的加入破坏了PHBV/EVA共混物的结晶，使其结晶度降低；当OMMT含量为7份（质量份，下同）时，PHBV/EVA/OMMT的结晶度最低，为43.4 %；随着OMMT含量的增加，PHBV/EVA/OMMT样条的断裂伸长率和冲击强度先升高后降低，当OMMT含量为3份时，其断裂伸长率较PHBV/EVA提升了38.3 %，冲击强度提升了52.5 %；加入OMMT后，PHBV/EVA样条的冲击断面变得更加粗糙。

Modification of PHBV/EVA Blends with OMMT

Poly（3-hydroxybutyrate-co-3-hydroxyvalerate） （PHBV）/ethylene-vinyl acetate elastomer （EVA）/organically modified montmorillonite （OMMT） blends were prepared through melting blending using OMMT as a modifier. Their rheological， crystalline， mechanical， and thermal properties as well as morphology were characterized using a rotational rheometer， differential scanning calorimeter， infrared spectrometer， universal testing machine， thermal weight loss analyzer， polarized light microscope and scanning electron microscope. The results indicated that the blends achieved an increase in loss modulus and complex viscosity with an increase in the OMMT content. OMMT can induce an intercalation structure in the blends. The addition of OMMT deteriorated the crystallization of the blends， resulting in a decrease in crystallinity. The blends exhibited the lowest degree of crystallinity of 43.4 % at an OMMT content of 7 phr. Their elongation at break and impact strength increased at first and then decreased with an increase in the OMMT content. Compared to the PHBV/EVA binary blends， the ternary blends with 3 phr of OMMT achieved an increase in elongation at break by 38.3 % and in impact strength by 52.5 %. Their impact facture surface became rougher with the addition of OMMT.