1)抗氧化剂 塑料中的不饱和双键受氧原子、热与光的侵袭而引起断裂产生自由基，由此引起连锁反应，使分子链断裂或形成链交联，而导致塑料成品的强度降低或变脆。抗氧化剂的功能就在于延缓塑料因氧化而分解，延长塑料产品的寿命。(2)抗静电剂 抗静电剂的主要功能是赋予塑料产生导电性，以使其避免因摩擦而造成静电的积存。常用的抗静电剂有四级铵盐、乙氧化胺类、脂肪酸酯类与磺化蜡类等。(3)发泡剂 塑料用发泡剂主要有三类：①氮气、二氧化碳及空气，直接压入塑料熔胶中使发泡；②挥发性液体如丁烷、戊烷、石油醚、二氟二氯甲烷等，在升温后即挥发膨胀，而使塑料体发泡，常见的聚苯乙烯泡绵即属于这类型；③分解性化学发泡剂，这类发泡剂一般为固体粉末，它们在加热时即分解放出气体（通常为氮或二氧化碳），而使塑料产生细胞状结构，并减轻重量。该类发泡剂多为有机的偶氮化合物，如偶氮双甲酰胺、偶氮二异丁腈。发泡的塑料主要有：ABS、PS、PVC、PU、EVA、PE、PP等。

1) the unsaturated double bond in the antioxidant plastics breaks through the invasion of oxygen atoms, heat and light, resulting in the production of free radicals, resulting in chain reaction, breaking the molecular chain or forming chain crosslinking, resulting in the decrease or brittleness of the finished products. The function of antioxidants is to delay the decomposition of plastics by oxidation and prolong the life of plastic products. (2) the main function of antistatic antistatic agents is to give plastic electrical conductivity to avoid the accumulation of static electricity caused by friction. The commonly used antistatic agents are four grade ammonium salt, ethoxylate, fatty acid ester and sulfonated wax, etc. (3) plastic foaming agent foaming agent has three main categories: nitrogen, carbon dioxide and air directly into the plastic melt in the foaming; the volatile liquid such as butane, pentane, petroleum ether, dichloromethane two fluorine, heating up after volatile expansion, and make plastic foam, common polystyrene foam that belongs to this type; the decomposition of chemical foaming agent, this kind of foaming agent is solid powder, which is heated in the gas decomposition (usually nitrogen or carbon dioxide), and the plastic cellular structure, and reduce weight. This kind of foaming agent is mostly organic azo compounds, such as azo dimethamide and azo two isobutadionitrile. The foamed plastics are mainly: ABS, PS, PVC, PU, EVA, PE, PP and so on.