Scholarlink

<p>Glycerol migration in thermoplastic starch/poly(lactic acid)/poly(butylene adipate-co-terephthalate) (TPS/PLA/PBAT) blends presents a critical challenge by compromising melt stability, interfacial adhesion, and mechanical performance. This study reveals that strategic control of twin-screw extrusion parameters can induce a processing-driven multiscale physicochemical confinement, effectively limiting glycerol diffusion and thereby eliminating the requirement for external additives. Comprehensive characterization via oscillatory shear rheology, capillary rheometer, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, differential scanning calorimetry, and Fickian diffusion modeling reveals that optimized conditions enhance TPS dispersion and interfacial adhesion. The effective glycerol diffusion coefficient decreased by approximately 38% with increased screw speed at 180&#xa0;°C and by around 69% with elevated temperature at 180&#xa0;rpm. The combination of morphological and rheological evidence elucidates a confinement mechanism induced by processing. SEM directly verified interfacial expansion resulting from shear, while a distinct viscoelastic relaxation mode, serving as a rheological fingerprint, was identified. We interpret this confinement to arise from a synergy of three effects: the partial weakening of hydrogen-bond relaxation in the TPS-glycerol network, polarity-mediated interfacial resistance that enhances tortuosity, and the encapsulation of refined TPS microdomains by the PLA/PBAT matrix. The latter critically depletes accessible –OH groups and prolongs bulk diffusion pathways. The established processing window (≈ 190&#xa0;°C, 180–200&#xa0;rpm) ensures sustained melt processability while suppressing diffusion, as evidenced by a coefficient of around 1.23 × 10⁻⁷ cm² s⁻¹, a 48% reduction from the 170&#xa0;°C baseline. This synergy between processing parameters and material properties offers a controllable route to stabilize plasticizer content and tailor morphology in TPS-based systems.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

The Role of Mixing Conditions in Governing Thermoplastic Starch Dispersion and Glycerol Migration

  • 期刊论文

  • 发表日期：

    2026年3月6日

查看全文
  • Nattawat Surathin,
  • Rungsima Yeetsorn,
  • Jatesuda Jirawutthiwongchai,
  • Siwarutt Boonyarattanakalin,
  • Werawat Lertwanawatana

摘要

Glycerol migration in thermoplastic starch/poly(lactic acid)/poly(butylene adipate-co-terephthalate) (TPS/PLA/PBAT) blends presents a critical challenge by compromising melt stability, interfacial adhesion, and mechanical performance. This study reveals that strategic control of twin-screw extrusion parameters can induce a processing-driven multiscale physicochemical confinement, effectively limiting glycerol diffusion and thereby eliminating the requirement for external additives. Comprehensive characterization via oscillatory shear rheology, capillary rheometer, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, differential scanning calorimetry, and Fickian diffusion modeling reveals that optimized conditions enhance TPS dispersion and interfacial adhesion. The effective glycerol diffusion coefficient decreased by approximately 38% with increased screw speed at 180 °C and by around 69% with elevated temperature at 180 rpm. The combination of morphological and rheological evidence elucidates a confinement mechanism induced by processing. SEM directly verified interfacial expansion resulting from shear, while a distinct viscoelastic relaxation mode, serving as a rheological fingerprint, was identified. We interpret this confinement to arise from a synergy of three effects: the partial weakening of hydrogen-bond relaxation in the TPS-glycerol network, polarity-mediated interfacial resistance that enhances tortuosity, and the encapsulation of refined TPS microdomains by the PLA/PBAT matrix. The latter critically depletes accessible –OH groups and prolongs bulk diffusion pathways. The established processing window (≈ 190 °C, 180–200 rpm) ensures sustained melt processability while suppressing diffusion, as evidenced by a coefficient of around 1.23 × 10⁻⁷ cm² s⁻¹, a 48% reduction from the 170 °C baseline. This synergy between processing parameters and material properties offers a controllable route to stabilize plasticizer content and tailor morphology in TPS-based systems.