Naheed Shazia, Zuber Mohammad, Salman Mahwish, Rasool Nasir, Siddique Zumaira, Shaik Mohammed Rafi, Sharaf Mohammed A F, Abdelgawad Abdelatty, Sekou Doumbia, Awwad Emad Mahrous
Department of Chemistry, Government College University, Faisalabad 38030, Pakistan.
Department of Chemistry, University of Lahore, Lahore 54000, Pakistan.
Polymers (Basel). 2021 Jun 23;13(13):2060. doi: 10.3390/polym13132060.
In this study, we evaluated the morphological behavior of polyurethane elastomers (PUEs) by modifying the soft segment chain length. This was achieved by increasing the soft segment molecular weight ( = 400-4000 gmol). In this regard, polycaprolactone diol (PCL) was selected as the soft segment, and 4,4'-cyclohexamethylene diisocyanate (HMDI) and 1,6-hexanediol (HDO) were chosen as the hard segments. The films were prepared by curing polymer on Teflon surfaces. Fourier transform infrared spectroscopy (FTIR) was utilized for functional group identification in the prepared elastomers. FTIR peaks indicated the disappearance of -NCO and -OH groups and the formation of urethane (NHCOO) groups. The morphological behavior of the synthesized polymer samples was also elucidated using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The AFM and SEM results indicated that the extent of microphase separation was enhanced by an increase in the molecular weight of PCL. The phase separation and degree of crystallinity of the soft and hard segments were described using X-ray diffraction (XRD). It was observed that the degree of crystallinity of the synthesized polymers increased with an increase in the soft segment's chain length. To evaluate hydrophilicity/hydrophobicity, the contact angle was measured. A gradual increase in the contact angle with distilled water and diiodomethane (38.6°-54.9°) test liquids was observed. Moreover, the decrease in surface energy (46.95-24.45 mN/m) was also found to be inconsistent by increasing the molecular weight of polyols.
在本研究中，我们通过改变软段链长来评估聚氨酯弹性体（PUEs）的形态行为。这是通过增加软段分子量（= 400 - 4000 g/mol）来实现的。在此方面，选择聚己内酯二醇（PCL）作为软段，4,4'-环己烷二异氰酸酯（HMDI）和1,6 -己二醇（HDO）作为硬段。通过在聚四氟乙烯表面固化聚合物来制备薄膜。利用傅里叶变换红外光谱（FTIR）对制备的弹性体中的官能团进行鉴定。FTIR峰表明 -NCO和 -OH基团消失以及氨基甲酸酯（NHCOO）基团形成。还使用扫描电子显微镜（SEM）和原子力显微镜（AFM）技术阐明了合成聚合物样品的形态行为。AFM和SEM结果表明，PCL分子量的增加增强了微相分离程度。使用X射线衍射（XRD）描述了软段和硬段的相分离及结晶度。观察到合成聚合物的结晶度随着软段链长的增加而增加。为了评估亲水性/疏水性，测量了接触角。观察到与蒸馏水和二碘甲烷（38.6° - 54.9°）测试液体的接触角逐渐增加。此外，还发现随着多元醇分子量的增加，表面能的降低（46.95 - 24.45 mN/m）也不一致。
