Kaplan Matay, Ciesielski Michael, Fuchs Sabine, Getterle Christoffer, Schönberger Frank, Pfaendner Rudolf
Fraunhofer Institute for Structural Durability and System Reliability LBF, 64289 Darmstadt, Germany.
Hamm-Lippstadt University of Applied Sciences, 59063 Hamm, Germany.
Polymers (Basel). 2023 Jul 27;15(15):3195. doi: 10.3390/polym15153195.
The increasing demand to provide sustainably produced plastic materials requires, a.o., the development of biobased flame retardants (FRs) for applications where flame retardancy is essential. To meet those challenging new sustainability requirements, a set of novel phosphorus-containing cellulose esters were synthesized by an efficient two-step procedure. In the first step, cellulose was treated with acrylic anhydride to synthesize acrylate-functionalized cellulose esters-more specifically, cellulose acrylate butyrate (CeAcBu) and propionate (CeAcPr). Subsequently, phosphorylated anhydro erythritol (PAHE), synthesized from the sugar alcohol erythritol, was added to the acrylate-functionalized cellulose esters via Phospha-Michael addition. For comparison a cellulose ester based on 6-Dibenzo[,][1,2]oxaphosphorin-6-on (DOPO) was prepared analogously. The acrylate-functionalized cellulose esters and novel FRs were characterized by NMR spectroscopy. TGA investigations of PAHE-functionalized CeAcBu revealed an onset temperature of decomposition (2% mass loss) of approx. 290 °C. The novel PAHE-based FR was incorporated into a polypropylene-polyethylene copolymer (PP--PE) together with poly-tert-butylphenol disulfide (PBDS) (8 wt.%/2 wt.%) as a synergist. The PP-PE samples achieved V2 classification in the UL 94 V test. In addition, specimens of a rapeseed oil-based polyamide containing PAHE-functionalized CeAcBu at 20 wt.% loading yielded a V2 rating with short burning times.
对可持续生产的塑料材料的需求不断增加，这尤其需要开发用于阻燃至关重要的应用中的生物基阻燃剂（FRs）。为了满足这些具有挑战性的新的可持续性要求，通过高效的两步法合成了一组新型含磷纤维素酯。第一步，用丙烯酸酐处理纤维素以合成丙烯酸酯官能化的纤维素酯，更具体地说，纤维素丙烯酸丁酯（CeAcBu）和丙酸酯（CeAcPr）。随后，由糖醇赤藓糖醇合成的磷酸化脱水赤藓糖醇（PAHE）通过磷迈克尔加成反应添加到丙烯酸酯官能化的纤维素酯中。为了进行比较，类似地制备了基于6-二苯并[，][1,2]氧杂磷杂环庚-6-酮（DOPO）的纤维素酯。通过核磁共振光谱对丙烯酸酯官能化的纤维素酯和新型阻燃剂进行了表征。对PAHE官能化的CeAcBu的热重分析（TGA）表明，分解起始温度（质量损失2%）约为290℃。将新型的基于PAHE的阻燃剂与作为增效剂的聚叔丁基苯酚二硫化物（PBDS）（8 wt.%/2 wt.%）一起掺入聚丙烯-聚乙烯共聚物（PP-PE）中。PP-PE样品在UL 94 V测试中达到了V2等级。此外，在20 wt.%负载量下含有PAHE官能化的CeAcBu的菜籽油基聚酰胺样品在短燃烧时间下获得了V2评级。
