Compatible and partly‐biobased poly(l‐lactide) (PLA)/polyamide‐12 (PA12) blends (30 wt% PA12) are here processed by twin‐screw extrusion at high shear without added compatibilizers and the effect of several processing parameters (screw speed, feed rate) on final properties (tensile strength, ductility, impact toughness, thermal resistance) is addressed. High tensile strengths could be maintained for these blends with a maximal ductility (225%) and impact toughness (48 kJ/m²) achieved for an optimal screw speed of 800 rpm. However, extreme screw speeds higher than 800 rpm dramatically reduce ductility and impact toughness. Concerning thermal resistance, a constant increase of the heat deflection temperature is observed with the screw speed and thermal resistance up to 123°C could be obtained. In this respect, processing conditions of PLA/PA12 blends have profound positive effects on all (thermo)mechanical properties. Blend morphologies were revealed by scanning electron microscopy and refined PA12 fibrils are detected at optimal processing conditions. Properties deterioration were correlated to a PA12 fibrillar‐to‐ellipsoidal shape transition at extreme screw speeds arising from PLA degradation and attesting for the importance of the PA12 fibrillation process on final properties. Consequently, PLA/PA12 blends represent interesting biobased candidates for high‐performance applications and their optimization could be easily performed by playing with extrusion conditions without compatibilizers.

中文翻译：

---

使用不具有增容剂的高剪切挤出工艺，可增强生物基聚（丙交酯）/聚（酰胺-12）共混物的（热）机械性能

相容的且部分生物基的聚（l-丙交酯）（PLA）/聚酰胺12（PA12）共混物（30 wt％PA12）在不增加增容剂的情况下通过双螺杆挤出在高剪切条件下进行加工，并且不影响多个加工参数（解决了最终性能（拉伸强度，延展性，冲击韧性，耐热性）对螺杆转速，进给速度的影响。这些共混物可保持高拉伸强度，并具有最大的延展性（225％）和冲击韧性（48 kJ / m ^2））以获得800 rpm的最佳螺杆速度。但是，高于800 rpm的极限螺杆速度会大大降低延展性和冲击韧性。关于热阻，随着螺杆速度观察到热变形温度恒定增加，并且可以获得高达123℃的热阻。在这方面，PLA / PA12共混物的加工条件对所有（热）机械性能均具有深远的积极影响。通过扫描电子显微镜揭示共混物的形态，并在最佳加工条件下检测出精制的PA12原纤维。在PLA降解引起的极限螺杆转速下，性能恶化与PA12纤维状到椭圆形的形状转变相关，并证明了PA12原纤化过程对最终性能的重要性。所以，