*Article* **Influence of Bio-Based Plasticizers on the Properties of NBR Materials**

### **Md Mahbubur Rahman 1,\*, Katja Oßwald 2, Katrin Reincke 2 and Beate Langer 1,2**


Received: 19 March 2020; Accepted: 27 April 2020; Published: 1 May 2020

**Abstract:** A high number of technical elastomer products contain plasticizers for tailoring material properties. Some additives used as plasticizers pose a health risk or have inadequate material properties. Therefore, research is going on in this field to find sustainable alternatives for conventional plasticizers. In this paper, two modified bio-based plasticizers (epoxidized esters of glycerol formal from soybean and canola oil) are of main interest. The study aimed to determine the influence of these sustainable plasticizers on the properties of acrylonitrile–butadiene rubber (NBR). For comparison, the influence of conventional plasticizers, e.g., treated distillate aromatic extract (TDAE) and Mesamoll ® were additionally investigated. Two types of NBR with di fferent ratios of monomers formed the polymeric basis of the prepared elastomers. The variation of the monomer ratio results in di fferent polarities, and therefore, compatibility between the NBR and plasticizers should be influenced. The mechanical characteristics were investigated. In parallel, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) were performed and filler macro-dispersion was determined. Bio-based plasticizers were shown to have better mechanical and thermal properties compared to conventional plasticizers. Further, thermo-oxidative aging was realized for 500 h, and afterwards, mechanical characterizations were done. It was observed that bio-based plasticizers have almost the same aging properties compared to conventional plasticizers.

**Keywords:** bio-oil; bio-based plasticizer; eco-friendly plasticizer; acrylonitrile-butadiene rubber; NBR; mechanical testing; thermo-oxidative aging
