Silane-modified polyurethanes (SPU-MDI, SPU-IPDI, and SPU-HDI) were synthesized by reacting various isocyanates (MDI, IPDI, and HDI) with poly(ether triol), followed by siloxane capping. The branched structures and properties of these SPUs were systematically characterized and evaluated. These SPU resins, upon moisture curing, yield elastomers exhibiting excellent mechanical properties and high transmittance (>92%). Incorporating polyether tertiary alcohol into the polymer chain markedly reduces the viscosity and average particle size of the SPUs due to its de-entangling effect. Specifically, the SPU-HDI resin displayed a low viscosity of 2548 mPa·s at 25 °C and an average particle size of 3.12 nm. Notably, elastomers derived from SPU-MDI and SPU-IPDI resins demonstrated tensile strengths greater than 10 MPa, surpassing that of SPU-HDI-based elastomer (∼5.0 MPa). This significant enhancement broadens the potential applications of these materials.

中文翻译：

---

高强度、高透明、低粘度的硅烷改性超支化聚氨酯

通过将各种异氰酸酯（MDI、IPDI和HDI）与聚醚三醇反应，然后进行硅氧烷封端，合成了硅烷改性聚氨酯（SPU-MDI、SPU-IPDI和SPU-HDI）。对这些 SPU 的支化结构和性能进行了系统的表征和评估。这些 SPU 树脂在湿气固化后产生的弹性体具有优异的机械性能和高透光率 (>92%)。将聚醚叔醇引入聚合物链中，由于其解缠结作用，显着降低了 SPU 的粘度和平均粒径。具体而言，SPU-HDI树脂在25℃下表现出2548mPa·s的低粘度和3.12nm的平均粒径。值得注意的是，由 SPU-MDI 和 SPU-IPDI 树脂衍生的弹性体表现出大于 10 MPa 的拉伸强度，超过了基于 SPU-HDI 的弹性体 (∼5.0 MPa)。这一显着增强拓宽了这些材料的潜在应用。