水性聚氨酯的制备及其在超纤革中的应用OA

To meet the stringent alkali resistance requirements of waterborne polyurethane(WPU)in microfiber synthetic leather production,this study systematically investigated the effects of key formulation parameters on WPU alkali resistance by screening monomer components.The influences of isocyanate type,polyol structure,isocyanate index(R value),dosage of 2,2-dimethylolpropionic acid(DMPA),and neutralization degree were comprehensively examined.The selection of appropriate monomers is critical,as the chemical structure of isocyanate and polyol components directly determines the hydrophilicity,crystallinity,and crosslinking density of the resulting polymer.The R value influences molecular weight and hardness,while DMPA dosage must be carefully balanced to avoid excessive water sensitivity.By systematically varying these parameters,the research aims to establish a robust formulation strategy that achieves both processability and superior alkali resistance. The experimental results demonstrated that the WPU film prepared with isophorone diisocyanate(IPDI)and polyether polyol(PPG-2000)exhibited superior alkali resistance.Under optimized conditions with R value of 1.5,DMPA dosage of 4%,and neutralization degree of 100%,the resulting WPU film showed an alkali absorption rate of only 5.58%after alkali treatment,indicating excellent resistance to alkaline environments.This remarkable performance can be attributed to the synergistic effects of the selected monomers and processing parameters,which enhance the structural stability and chemical resistance of the polymer matrix.The alicyclic structure of IPDI provides rigidity and hydrolysis resistance,while flexible polyether segments contribute to chain mobility and film integrity.Fourier transform infrared spectroscopy(FTIR)analysis confirmed the successful synthesis of the WPU structure,verifying the incorporation of key functional groups and supporting the correlation between molecular structure and observed alkali resistance properties. Furthermore,the applicability of the synthesized WPU in microfiber synthetic leather production was evaluated.The resulting microfiber leather demonstrated superior performance compared to the control sample prepared with commercial 5912(alkali-resistant)WPU.Key performance indicators,including breaking strength,fabric style,and alkali resistance,showed significant improvement.The enhanced breaking strength indicates better mechanical integrity essential for industrial durability,while improved fabric style suggests enhanced aesthetic and tactile qualities meeting consumer demands.Most importantly,the alkali resistance of the experimental sample exceeded that of the commercial counterpart,confirming the effectiveness of the optimized formulation in real-world processing conditions.The research provides a feasible formulation and process strategy for synthesizing high-performance alkali-resistant WPU,offering valuable insights for industrial applications,particularly in microfiber synthetic leather production where alkali resistance is crucial.The findings contribute to the development of advanced materials for the leather industry and potentially other fields requiring durable,alkali-resistant polymer coatings.