{
  "abstract": "As electronics become smaller and more power-dense, glass-fiber-reinforced polyamide 66 (PA66/GF) must combine halogen-free flame retardancy with electrical safety, including a glow-wire ignition temperature (GWIT) ≥ 775 °C and a comparative tracking index (CTI) ≥ 600 V. Conventional low-molecular-weight flame retardants often require loadings above 15 parts by mass, impairing mechanical and electrical properties. Here, a phosphorus-containing polyamide oligomer (DOPO–MA–oligomerPA6) was synthesized via a DOPO–MAH intermediate from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and maleic anhydride (MAH), followed by polymerization with ε-caprolactam, then melt-blended with aluminum diethylphosphinate (ADP) and melamine polyphosphate (MPP) in PA66/GF. Its oligo-PA6 backbone provides good compatibility with PA66, while its low molecular weight (Mn = 10,984 g mol−1; PDI = 2.569) favors dispersion. The phosphorus groups enhance the efficiency of the ADP/MPP system. With 4 parts oligomer and a total flame-retardant loading of 14 parts by mass per 100 parts PA66/GF, the composite achieved UL-94 V-0 rating, a limiting oxygen index (LOI) of 36.1%, a GWIT of 800 °C, and a CTI of 600 V. Its heat deflection temperature, tensile strength, notched impact strength, and flexural modulus were 178.8 °C, 95.0 MPa, 8.7 kJ m−2, and 8984 MPa, respectively. Compared with the conventional 20-part system, total additive loading decreased by 30%, with simultaneous improvements in flame retardancy, electrical safety, and mechanical properties. This offers a scalable route to high-performance PA66/GF composites.",
  "abstract_shown": true,
  "affiliations": [
    "College of Materials Engineering, North China Institute of Aerospace Engineering, Langfang 065000, China",
    "National Engineering Research Center of Engineering and Ecological Plastics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Xing Zhang"
    },
    {
      "affs": [
        0
      ],
      "name": "Lirong Xie"
    },
    {
      "affs": [
        0
      ],
      "name": "Zhongliang Zhang"
    },
    {
      "affs": [
        0
      ],
      "name": "Guanghao Guo"
    },
    {
      "affs": [
        1
      ],
      "name": "Zhichao Zhen"
    },
    {
      "affs": [
        0
      ],
      "name": "Xuran Liu"
    },
    {
      "affs": [
        1
      ],
      "name": "Dan Huang",
      "orcid": "0000-0002-0798-2065"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/b73084yvbv1c6.bib",
  "cited_by": 0,
  "doi": "10.3390/polym18212706",
  "fulltext_url": null,
  "id": "b73084yvbv1c6",
  "issns": [
    "2073-4360"
  ],
  "landing_url": "https://www.mdpi.com/2073-4360/18/21/2706",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [],
  "openalex": null,
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-01",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/b73084yvbv1c6.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:21:00Z",
      "native_id": "10.3390/polym18212706",
      "source": "crossref",
      "url": "https://www.mdpi.com/2073-4360/18/21/2706"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "issn:2073-4360",
      "subfield": "materials-polymers"
    }
  ],
  "title": "A Phosphorus-Containing Polyamide Oligomer as a Synergist for Flame-Retardant PA66/GF Composites: Concurrent Improvements in Flame Retardancy and Electrical Safety",
  "title_text": "A Phosphorus-Containing Polyamide Oligomer as a Synergist for Flame-Retardant PA66/GF Composites: Concurrent Improvements in Flame Retardancy and Electrical Safety",
  "type": "peer-reviewed",
  "updated_at": "2026-11-05T00:20:53Z",
  "url": "https://research.draconitic.com/paper/b73084yvbv1c6",
  "venue": "Polymers",
  "versions": []
}