Keratin Modified and Functionalized as a Reinforcement and Nucleation Agent of β-Polypropylene Composites

ABSTRACT

A new green β nucleating agent has been obtained from industrial waste. This way, pimelic acid (PA) was chemically supported on treated keratin fibers to promote the β polymorph into a polypropylene matrix using several percentages of reinforcement (0.5, 1.0, and 5.0% w/w). IR spectra suggest a successful functionalization showing the presence of a new band at 1571 cm⁻¹, indicating a bond between PA and the keratin surface. According to the scanning electron spectroscopy, the nucleating agent was homogeneously distributed on the keratin surface. Wide angle X-ray diffraction (WAXD) patterns and differential scanning calorimetry (DSC) curves demonstrate that the functionalized keratin fibers were able to promote a high percentage of β-crystal into the polypropylene matrix (79% and 60%, respectively). The thermomechanical properties were characterized by dynamic mechanical analysis (DMA). At −30°C, the new reinforcement provides an important increase of 25% in the storage modulus compared with the raw polypropylene. The new reinforcement seems to strongly influence the mobility of the amorphous phase, shifting the Tg to higher temperatures.

摘要

从工业废料中获得了一种新的绿色β成核剂. 通过这种方式，在处理过的角蛋白纤维上化学支撑庚二酸（PA），以使用几种增强百分比（0.5、1.0和5.0%w/w）将β多晶型物促进为聚丙烯基质. 红外光谱表明，成功的官能化显示了1571 cm-1处的新带，表明PA与角蛋白表面之间存在键合. 根据扫描电子光谱，成核剂均匀分布在角蛋白表面. 广角X射线衍射（WAXD）模式和差示扫描量热（DSC）曲线表明，功能化角蛋白纤维能够促进高百分比β-晶体进入聚丙烯基质（分别为79%和60%）. 通过动态力学分析（DMA）表征了其热机械性能. 在-30°C时，与原聚丙烯相比，新增强材料的储存模量显著增加了25%. 新的增强似乎强烈影响非晶相的流动性，将Tg转移到更高的温度.

KEYWORDS:

• Polypropylene
• chicken feathers
• composites
• chemical modification
• functionalization β-polypropylene
• keratin fiber

关键词:

• 聚丙烯
• 鸡毛
• 复合材料
• 化学改性
• 功能化β-聚丙烯
• 角蛋白纤维

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15440478.2022.2128144.

Additional information

Funding

The work was supported by the Consejo Nacional de Ciencia y Tecnología [957175]; National Technology of Mexico (TecNM) [14077.22-P].