Polymer crystallization rate challenges: The art of chemistry and processing

Abstract

The intention of this study is to discuss scientific advances toward one very important challenge in the polymer processing industry: How does one increase the crystallization rate of slow-to-crystallize polymeric materials, thereby facilitating processing and enabling peak product performance? In the medical device field, where both government-controlled regulatory entities and medical professionals closely scrutinize the biocompatibility of added crystallization rate enhancers, achieving these twin goals has always been challenging. Herein, we present a review of various chemical and physical approaches used to tune the crystallization rate of semicrystalline polymers, with a strong emphasis on two novel approaches recently discovered and developed in our laboratories.

Rapid fabrication of poly(DL-lactide) nanofiber scaffolds with tunable degradation for tissue engineering applications by air-brushing

“…Polymer blending can be utilized to adjust polymer fiber degradation rates while improving material processability. The Low MW polymers presumably act as plasticizers and improve scaffold quality by forming longer fibers (Andjelic et al 2015). …”

“…The collected SEM Images and GPC data suggests that the fibers degraded throughout the scaffolds uniformly and therefore likely underwent bulk degradation. PDLLA fiber scaffolds typically experience bulk material degradation due to the high surface to volume ratio of the fibers (Kim et al 2003, Zong et al 2003, Bini et al 2004, Andjelic et al 2015). …”

“…A polymer solution concentration above the chain overlap condition is required for fiber scaffold generation (Zhuang et al 2013). By changing polymer type, molecular weight, or through the use of polymer blends, properties such as polymer crystallization kinetics, bulk scaffold Young’s modulus, and degradation rate can be tailored for specific applications (Kim et al 2003, Dong et al 2009, Andjelic et al 2015). …”

Influence of graphene on thermal degradation and crystallization kinetics behaviour of poly(lactic acid)

“…Crystallization kinetics has direct effect on dimensional stability, mechanical and thermal performance of the final product [36]. In this processing technique, polymers should complete the crystallization process before leaving the mould cavity [37]. In such cases, faster crystallization process can have an advantage during fabrication using article throw injection moulding [37].…”

“…In this processing technique, polymers should complete the crystallization process before leaving the mould cavity [37]. In such cases, faster crystallization process can have an advantage during fabrication using article throw injection moulding [37]. …”