A new method was used to prepare ABS/PA6 blends by in situ polymerization and compatibilization method. In this process, e-caprolactam monomer was polymerized in presence of ABS via activated anionic polymerization to produce PA6. The main ingredients of the reaction mixture included: monomer (e-caprolactam), catalyst (Na-caprolactamate), microactivator (HDI) and macro-activator (SMA). Then, in different steps caprolactam/ABS composition, micro-activator and macro-activator concentrations were selected as the variables. ABS/PA6 blends were prepared in an internal mixer (at 200oC) at three levels of ABS/caprolactam compositions (25/75, 50/50, 75/25), with varied concentrations of HDI (4 and 6 phc) and macro-activator (0, 3 and 6 phc). As a result of all the variations the blends produced different morphologies. In samples with dispersed structure, the particle size reduced with higher macro-activator content. Also, the effect of macro-activator at lower level of HDI was more significant, probably due to the competition between the activators in the reaction. In some of the blends, dispersed particles with sizes under 100 nm were observed. The crystalline structure of PA6 phase was investigated using XRD and DSC tests, which also showed changes with regard to initial composition and activator contents. In pure samples only α-structure was detected, while in the blends of higher ABS content, g-form appeared and at the ABS content of 75% only g-form was observed. The crystallinity decreased as the function of ABS content. Pure synthesized PA6 showed higher Tm and Hc than the blends. The percentage crystallinity of the samples obtained from XRD and DSC tests showed good correlation.

In this study, polyamide 6 (PA6)/ nitrile butadiene rubber (NBR) based hybrid-nanocomposites reinforced with calcium carbonate and organo-clay as nanofillers in various content of 1, 3 and 5 phr were prepared and characterized. The nanocomposite samples were prepared through the melt processing method in an internal mixer. The effect of rubber phase (NBR) content (10, 30, and 50 wt. %), calcium carbonate content (1, 3, and 5 phr), and organo-clay content (1, 3, and 5) was investigated on morphology and mechanical properties of the nanocomposites. The mechanical properties were evaluated by tensile, flexural, and Charpy impact tests. The results showed that adding the NBR reduces the tensile strength, tensile modulus, flexural strength, and flexural modulus, and increases the impact strength. Introducing the nano-clay and calcium carbonate improves the tensile and flexural strength, tensile and flexural modulus, and decreases the impact strength. The nano-clay content from 1 to 3 phr improved the impact strength.

This work focuses on the preparation of copper nanoparticles-modified polyamide 6 composites (denoted as nano-Cu/PA6) by in situ polymerization, with which cupric oxide as metallic copper source is directly reduced to metallic copper in the process of the opening-ring polymerization of ε-caprolactam only using the reducing atmosphere of reaction system. The obtained composites are characterized by means of transmission electron microscopy, X-ray diffraction, laser granulometry instrument, and ultraviolet–visible absorption spectroscopy. Moreover, the friction and wear resistance, mechanical strength, and antistatic performance of as-prepared composites are also readily evaluated. The results show that cupric oxide as filler is reduced to metallic copper and the as-reduced copper nanoparticles with 4–5-nm-size clusters separately disperse in polyamide 6 (PA6) matrix. Additionally, the addition content (mass fraction) of cupric oxide has significant effect on the crystalline form of PA6, and γ crystalline form of PA6 is predominant when higher dosage of CuO is introduced to fabricating nano-Cu/PA6 composites. Moreover, introducing a proper amount of CuO filler favors to generate nano-Cu/PA6 composites with improved mechanical properties and wear resistance. Particularly, nano-Cu/PA6 composite prepared at a CuO content of 0.5 % possesses the best tensile strength and wear resistance, showing promising application as a functional polymer-matrix composite.

In this work, melamine cyanurate (MCA) and boehmite (BM) were used to improve the flame retardancy of polyamide 6 (PA6), and a series of BM/MCA/PA6 composites were prepared. The effects of MCA and BM on flame retardancy, combustion and thermal degradation behavior of 15-MCA/PA6 and BM/MCA/PA6 composites were investigated by methods of limited oxygen index (LOI) measurement, vertical burning test, cone calorimeter test and thermogravimetric analysis (TGA). The results showed that MCA can effectively flame retardant PA6. When 15 wt% MCA was added to PA6, composite sample (15-MCA/PA6) possessed LOI value of 30. 4% and V0 rating (3. 2 mm) in UL-94 test. By replacing part of MCA with BM, with an increase of BM amount, the flame retardancy of BM/MCA/PA6 composite was better at first, but then got worse, and mechanical properties were increased. The flame retardancy, thermal stability and combustion behavior data of 4-BM/11-MCA/PA6 composite were better than 15-MCA/PA6 composite, indicated that appropriate amounts of MCA and BM in PA6 had synergistic flame-retardant effects. The time to ignition (TTI), the peak of heat release rate (PHRR), total heat rate (THR), total smoke release /total mass loss (TSR/TML) and fire performance index (FPI) of 4-BM/11-MCA/PA6 composite were 53 s, 322. 5 KW. m−, 2, 79. 8 MJ. m−, 2, 98. 3 g−, 1 and 0. 16 s. m2. kw−, 1, respectively. The LOI value of 4-BM/11-MCA/PA6 composite was 33. 8% with V0 rating (2. 0 mm) in UL-94 test.

Nanocomposite gears based on Polyamide 6/Polypropylene (PA6/PP 67/33) blend containing 2.5 to 10 phr of nano-CaCO3 and 5 phr of maleated polypropylene (PP-g-MAH) as compatibilizer were produced by injection molding. The morphology was studied using scanning electron microscopy. The wear and temperature of gears teeth as well as gears working lives were characterized by employing a gear test rig under two different output torques including 8.9 and 14.8 Nm. In all experiments, the teeth’s temperature and wear values for driver gear were higher as compared to those of driven gear. The incorporation of 2.5 and 5 phr nano-CaCO3, led to the reduction of temperature and wear rate of gears. The wear rates of gears containing 2.5 phr of nano-CaCO3, under the torque of 8.9 and 14.8 Nm, were 60 and 83% lower than those of neat PA6 gears respectively. The maximum gear life under the torque of 14.8 Nm (63000 revolutions) was observed in nanocomposite gears containing 2.5 phr of nano-CaCO3 which was nearly 200% higher than that of neat PA6 gears (21000 revolutions). The raise of Polymer based gears performances as a result of CaCO3 nanoparticles inclusion may be attributed to the improvements of gear teeth flexural, wear and heat resistances.

Nanocomposites based on PA6/ABS (60/40) containing 3 phr of POE-gr-MA and 2, 5 and 8 wt.% of CaCO3 nanoparticles (10-15 nm) were prepared by melt compounding, using a co-rotating twin-screw extruder, followed by injection molding process. The morphology and impact properties were characterized. The inclusion of coated CaCO3 nanoparticles into PA6/ABS altered the morphology, and as a consequence, ABS particle size in PA6 matrix was increased. This result was attributed to the nonpolar natures of ABS and coated CaCO3 as well as very small nanoparticles’ size. Incorporation of CaCO3 nanoparticles noticeably affected the impact properties. By adding 2 wt.% of nanoparticles, the impact strength in notched samples was increased as high as 160% when compared to net PA6/ABS. Due to their high flexibility, no break was observed in unnotched samples containing 2 and 5 wt.% of nanoparticles.