Preparation and property of waterborne UV‐curable chain‐extended polyurethane surface sizing agent: Strengthening and waterproofing mechanism for cellulose fiber paper

Abstract

Waterborne UV-curable polyurethane (UWPU) dispersions with different hydrophilicity and functionalities were prepared by varying the content of dimethylol butanoic acid (DMBA) and pentaerythritol triacrylate (PETA). And linear and cyclic chain extenders with different functionalities were also incorporated into the UWPU backbone, including isophorone diamine (IPDA), diethylene triamine (DETA), and ethylene diamine (EDA). Effects of DMBA content, PETA content, photoinitiator content, UV curing time, chain extender on the properties of UWPU dispersions and films, as well as the properties of the unsized and sized paper were investigated. The water resistance and mechanical properties of sized paper were greatly relied on the particle size, the molecular weight, the croslinking density, and penetrability of UWPU. UWPU dispersion chain extended with IPDA (IPDA-UWPU) displayed smaller particle size than that of UWPU. The paper sized with IPDA-UWPU was endowed with best water resistance, tensile strength, folding strength and surface strength. XPS depth analysis revealed that IPDA-UWPU exhibited better penetrability into the paper substrate than UWPU. SEM and AFM demonstrated that the smoothness of sized paper was improved, and the bond strength between fibers was enhanced. The obtained UWPU could be directly used as an effective and fast drying surface sizing agent for cellulose fiber paper.

Process development of water-based polyurethane with acrylate terminal group under water vapor permeability and water repellency for nylon fabric

“…The characteristic peaks at 3264 and 1720 cm À1 were assigned to -NH and -C¼O stretching vibration, respectively. The peaks of the main groups of acrylate included the peak 30 of C¼O at 1721 cm À1 and the peak 29 of CH 2 at 2900-3130 cm À1 . According to Figure 1, there was a dynamic change in the absorption pattern of the C¼O stretching region, which may be attributed to the presence of the acrylate group.…”

“…Therefore, the content of DMPA is one of the important considerations in preparing WPU. Some studies have discussed the effect of different hydrophilic group materials on WPU, 28,29 but the neutralizer TEA is seldom replaced by other materials in order to reduce hazards to the human body during the process.…”

A novel polymeric fluorescent brightener agent based on 4,4′-diamino-stilbene-2,2′-disulfonic acid-triazine structure: synthesis, characterization, photo-property, and performance on paper as light stabilizer, fluorescent brightener, and surface-sizing agent

“…Compared with blank paper sheet, whose surface strength and smoothness are 0.69 m s -1 and 37.6 s, the surface strength of paper sheets treated with 0.2, 0.4, 0.6, and 0.8 wt% of PFBD, respectively, increase by 0.76, 1.15, 1.51, and 1.84 m s -1 . Meanwhile, the smoothness of surface-sized paper sheets, respectively, boosts by 45.5, 50.9, 54.1, and 56.7 s. Therefore, with the increase concentration of PFBD, the surface strength and smoothness of paper sheets are heightened, which indicates that PFBD has good film-forming property, which can be applied in the paper industry as a surface-sizing agent [34,35] (the coating weights of PFBD are 0.1, 0.2, 0.3, and 0.4 g m -2 , while the dosages of PFBD are 0.2, 0.4, 0.6, and 0.8 wt%).…”

Hydrophobic copolymers added with starch at the size press of a paper machine: A review of findings and likely mechanisms

“…For instance, Carceller and Juppo (2004) observed 30 nm particles based on field-emission scanning electron microscopy under freezing conditions, when studying a styrene-acrylate ester derivative mixed with a starch solution. In addition to electron microscopy, some other researchers have based their size analysis on rates of Brownian diffusion, using light scattering methods to evaluate hydrophobic substances that have been added with size press starch (Yang and Deng 2000;Guo et al 2012Guo et al , 2014Xu and Hu 2012;Wang et al 2015a;Fei et al 2017). The development of such methods may give the impression that the addition of hydrophobic nanoparticles or microscopic particles at the size press may be something new.…”