Natural rubber (NR) grafted by methyl methacrylate (MMA) was used to produce bio-based wood adhesive. The effect of total solid content (%TSC) at 55, 57, and 60%, represented as 55NR-g-MMA, 57NR-g-MMA, and 60NR-g-MMA, respectively, and the effect of storage time on lap shear strength were investigated. It was found that contact angle sharply decreased from 95° for NR to approximately 65° for all of NR-g-MMAs. Because the MMA groups were incorporated into various NR-g-MMA samples and the highest relative amount of grafted MMA was obtained by 57-NR-g-MMA which is determined by peaks intensities ratio between wave number at 1725 (C=O stretching) and 1450 (CH 2 stretching), investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). These influences resulted in an increase in storage modulus ( E ′), whereas tan δ was decreased as compared to that of NR, characterized by dynamic mechanical analyzer (DMA). In addition, the apparent viscosity performed by plate-and-plate rheometer trended to increase with total solid content and storage time. However, the highest lap shear strength was achieved by 57NR-g-MMA. It means that the lap shear strength was not only governed by viscosity as well as total solid content, but the amount of grafted MMA also plays an important role.

中文翻译：

---

天然橡胶生物基木材胶粘剂的制备与表征：总固含量、粘度和储存时间的影响

由甲基丙烯酸甲酯（MMA）接枝的天然橡胶（NR）用于生产生物基木材胶粘剂。总固体含量（%TSC）在 55%、57% 和 60% 时的影响，分别表示为 55NR-g-MMA、57NR-g-MMA 和 60NR-g-MMA，以及储存时间对搭接的影响剪切强度进行了研究。发现接触角从 NR 的 95° 急剧下降到所有 NR-g-MMA 的约 65°。因为 MMA 基团被掺入各种 NR-g-MMA 样品中，并且接枝 MMA 的最高相对量是通过 57-NR-g-MMA 获得的，这由 1725 处波数之间的峰强度比决定（C = O 拉伸）和 1450（CH 2 拉伸），通过衰减全反射傅里叶变换红外光谱 (ATR-FTIR) 进行研究。这些影响导致储能模量（E'）增加，而与 NR 相比，tan δ 降低，由动态机械分析仪 (DMA) 表征。此外，板板式流变仪的表观粘度随着总固体含量和储存时间的增加而增加。然而，最高搭接剪切强度是由 57NR-g-MMA 实现的。这意味着搭接剪切强度不仅受粘度和总固体含量的控制，而且接枝 MMA 的量也起着重要作用。