提高共混物相容性方法

Methods to improve the compatibility of blends

二

Two

聚合物之间的相容性比较复杂，有的完全相容或部分相容；有的完全不相容或部分不相容。共混物完全相容是因为极性相同而结构相似，此类共混物性能改善不大。

The compatibility between polymers is rather complex, some are completely compatible or partially compatible, some are completely incompatible or partially incompatible. The compatibility of the blends is similar because of the same polarity and similar structure.

绝大多数的共混体系内聚合物之间只能部分相容。因此要想到达预期的改性效果，必须通过各种共混改性方法，例如：加入相容剂、交联、IPN、引入基团和改变结构等技术改善聚合物之间的相容性。

In most of the blend systems, polymers can only be partially compatible. Therefore, in order to achieve the desired modified effect, the compatibility between the polymers must be improved through a variety of blending modification methods, such as adding compatibilizer, crosslinking, IPN, introducing group and changing structure.

（1）加入相容剂

(1) adding compatibilizer

加入相容剂，使两种或多种聚合物组分通过混炼，提高相界面层的黏结力，促进相分散，使形态结构稳定化，并借助聚合物分子间的键合力，降低两相组分间的界面张力，增加共混体系的均匀性，减小相分离，改善聚合物共混的综合性能。

With the addition of compatibilizer, two or more polymer components are mixed to improve the bonding force of the interface layer, promote the phase dispersion, stabilize the morphology and structure, and reduce the interfacial tension between the two components, increase the uniformity of the blend system, reduce the phase separation and improve the polymer blending. The comprehensive performance.

PE、PP、PS等聚烯烃之间，性能具有互补性但却缺乏良好的相容性，因此加入相容剂是必要的。PE/PP共混物两组分相容性差，但加入15%相容剂EPR后，其形态结构均化以及相界面黏结得到强化，性能有了明显改善。又如：PBT与PPO完全不相容且成型性极差，加入5%～8%带有环氧基的PS接枝相容剂，改善了PBT与PPO的相容性，并促进力学与加工性能大大提高。

PE, PP, PS and other polyolefin have complementary properties but lack good compatibility, so adding compatibilizer is necessary. The compatibility of the two components of PE/PP blends is poor, but after adding 15% compatibilizer EPR, the morphology and structure of the blend and the bonding of the phase interface are strengthened, and the properties of the blends have been improved obviously. Also such as: PBT and PPO are completely incompatible and the formability is extremely poor, adding 5% to 8% PS grafted compatibilizer with epoxy based, improves the compatibility between PBT and PPO, and promotes the mechanical and processing properties to be greatly improved.

（2）交联反应

(2) cross linking reaction

聚合物交联反应属于化学改性在塑料行业中应用较为广泛。交联是指在聚合物大分子链之间产生的化学反应，从而形成化学键的过程。交联反应如果是在相互不相容的聚合物之间，可大大提高两种聚合物的相容性，甚至使不相容组分变为相容组分。

Polymer crosslinking reaction belongs to chemical modification in plastic industry. Crosslinking refers to the chemical reaction between polymer chains and the formation of chemical bonds. If the crosslinking reaction is between the incompatible polymers, the compatibility of the two polymers can be greatly improved, and even the incompatible components can be changed into compatible components.

交联可分为化学交联和物理交联两种情况。例如：用辐射的方法使LDPE/PP产生化学交联。结晶作用属于物理交联，由于取向纤维组织的结晶，使已形成的共混物形态结构稳定，从而产生相容作用。

Crosslinking can be divided into two cases: chemical crosslinking and physical crosslinking. For example, chemical crosslinking of LDPE/PP is made by radiation. Crystallization belongs to physical crosslinking. Because of the crystallization of oriented fibrous structure, the morphology and structure of the resulting blends are stable, resulting in compatibility.

用于提高聚合物共混组分相容性的交联，大多数企业采用动态交联方式。动态交联即可实现共混物的相容，又可提高共混物的综合性能，同时又不失去其固有的热塑性，仍然可用热塑性塑料成型加工方法加工。

Crosslinking is used in most enterprises to improve compatibility of polymer blend components. The compatibility of the blends can be achieved by dynamic crosslinking, and the comprehensive properties of the blends can be improved, while the inherent thermal plasticity is not lost, and it can still be processed by the thermoplastic molding process.