由于木粉中主要成分是纤维素，纤维素中含大量的羟基，这些羟基形成分子间氢键或分子内氢键，使木粉具有吸水性，吸湿率可 达8％～12％，且极性很强；而热塑性塑料多数为非极性的，具有疏水性，所以两者之间的相容性较差，界面的粘结力很小。使用适当的添加剂来改性聚合物—木粉表面，可以提高木粉与树脂之间的界面亲和能力，且改性的木粉填料具有增强的性质，能够很好地传递填料与树脂之间的应力，从而达到增强复合材料强度的作用。因此，要得到性能优良、符合条件的塑木复合材料，首先要解决的是材料相容性的问题。

The main component of wood powder is cellulose, and the cellulose contains a large number of hydroxyl groups. These hydroxyl groups form intermolecular hydrogen bonds or intramolecular hydrogen bonds. The wood powder has water absorption, the moisture absorption rate can reach 8% to 12%, and the polarity is very strong, while most of the thermoplastic plastics are non polar and hydrophobic, so the compatibility between them is more than that of them. Poor bonding force of the interface is very small. The use of appropriate additives to modify the polymer - wood flour surface can improve the interface affinity between the wood powder and the resin, and the modified wood powder filler has an enhanced property, which can transfer the stress between the filler and the resin very well, thus enhancing the strength of the composite. Therefore, in order to get good performance and qualified wood plastic composites, the first thing is to solve the problem of material compatibility.

相容性问题主要靠加入各种添加剂来解决。

Compatibility is mainly solved by adding various additives.

(1)偶联剂法

(1) coupling agent method

偶联剂可以提高无机填料、无机纤维与基体树脂之间的相容性，同时也可改善木粉与聚合物之间的界面状况。硅烷偶联剂和钛酸酯偶联剂是应用最广泛的两类偶联剂。实验表明，这两种偶联剂都能改善填料与树脂的相容性。

The coupling agent can improve the compatibility between inorganic filler, inorganic fiber and matrix resin, and also improve the interface state between wood flour and polymer. Silane coupling agents and titanate coupling agents are the two most widely used coupling agents. Experiments show that these two coupling agents can improve the compatibility of fillers and resins.

(2)相容剂法

(2) compatibilizer method

加入相容剂是最简单而且很有效的方法。据报道，合适的相容剂有马来酸酐等接枝的植物纤维或马来酸酐改性的聚烯烃树脂、丙烯酸酯共聚物、乙烯丙烯酸共聚物。这些相容剂中大部分含有羧基或酐基，能够与木粉中的羟基发生酯化反应，从而降低木粉的极性和吸湿性，使其与树脂有很好的相容性。

Adding compatibilizer is the simplest and most effective method. It is reported that the suitable compatibilizer is grafted plant fiber or maleic anhydride or maleic anhydride modified polyolefin resin, acrylate copolymer and vinyl acrylic copolymer. Most of these compatibilizer contains carboxyl or anhydride, which can be esterified with the hydroxyl group in wood powder, thus reducing the polarity and hygroscopicity of the wood powder, so that it has good compatibility with the resin.