Polylactide (PLA) composites with various talc content were prepared by melt extrusion. The thermal, dynamic mechanical, tensile and flexural properties, and fracture surface morphologies of neat PLA and PLA/talc composites were investigated and compared. The results showed that talc had significant nucleation effect and the cold crystallization temperature of PLA decreased with talc concentration. The thermal degradation and heat distortion temperature of PLA were slightly enhanced by compounding with talc. Talc showed significant reinforcing and toughening effects on PLA, the tensile strength, flexural strength and modulus increased with talc content ranging from 0 to 24.3 wt %. The results of tensile test showed that the elongation at break increased with talc content up to 18.1 wt % with obvious changes in fracture behavior, changing from brittle to ductile, when talc content increased to 24.3%, samples failed in a brittle manner with low elongation at break. The fracture surface morphologies showed that the talc layers were partially delaminated, aligned along the flow direction, and uniformly dispersed in the PLA matrix. The results obtained by SEM and FTIR confirmed that the interfacial adhesion between talc and PLA matrix was good. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A series of the reinforced and toughened polylactide (PLA) composites with different content of basalt fibers (BF) were prepared by twin screw extruder. The toughness of BF/PLA composites was improved further by the addition of polyoxyethylene grafted with maleic anhydride (POE-g-MAH), ethylene-propylene-diene rubber grafted with maleic anhydride (EPDM-g-MAH), and ethylene-acrylate-glycidyl methacrylate copolymer (EAGMA), relatively. The mechanical properties, rheology, crystallization, and morphology of BF/PLA composites were studied. The results showed that basalt fiber had significant reinforcing and toughening effect in comparsion with glass fiber. EAGMA was more effective in toughening BF/PLA composites than POE-g-MAH and EPDM-g-MAH. When the content of EAGMA achieved to 20 wt %, the impact strength of BF/PLA/EAGMA composite increased to 33.7 KJ/m 2 , meanwhile the value was improved by 71.1% compared with pure PLA. According to dynamic rheometer testing, the use of the three kinds of elastomers increased the melt dynamic viscosity. Differential scanning calorimetry analysis showed that POE-g-MAH and EPDM-g-MAH can decrease the cold crystallization temperature (T cc ) to approximately 20 C and dramatically improve crystallinity (v c ) of BF/PLA composites.

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Silica is the most widely‐used filler to reinforce liquid silicone rubber (LSR), but the high viscosity of LSR/silica suspension significantly limits its processing flexibility. To balance the processibility and reinforcing efficiency of LSR/silica systems, two kinds of enols (propenol and 1‐undecylenyl alcohol) and a saturated alcohol (1‐undecylic alcohol) were employed to modify the silica surface. Various rheological tests were carried out to investigate the processibility as well as filler networking and crosslinking processes of the modified systems. Tensile tests were also adopted to verify the reinforcing effect. It was found that surface modification of silica by 1‐undecylenyl alcohol could significantly reduce the viscosity of its suspension with LSR. Meanwhile, the mechanical strength of LSR could be largely enhanced by six times with 10 wt % modified silica. This work will merit design and production of LSR materials with balanced processibility and mechanical performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45544.

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A series of the thermal conductive polyamide 66 (PA66) composites were prepared by two methods, including extrusion method (EM) and solution method (SM). The thermal conductivity, mechanical properties, thermal stability, and electric property of PA66 composites were investigated. The results showed that the maximum value of thermal conductivity of carbon fiber/PA66 composites containing 40 wt% carbon fiber prepared by SM achieves 2.537 W/mÁK, which was superior to that of carbon fiber/PA66 composites prepared by EM at the same carbon fiber content. Moreover, its value was eight times more than that of pure PA66. The orientation of carbon fiber in process of injection had an influence on thermal conductivity of carbon fiber/PA66 composites, and the perpendicular distribution of carbon fibers helped in improving the thermal conductivity of composites. The carbon fiber/PA66 composites had good heat conducting performance but also had good material properties and electrical properties.

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