Group 1 - The event commemorated the 80th anniversary of the victory in the Chinese People's Anti-Japanese War and the World Anti-Fascist War, featuring the release of 80,000 balloons and doves [1] - The balloons used in the event are made from fully biodegradable natural materials, differing significantly from conventional balloons [1] - The materials used include natural latex, plant starch, and polylactic acid (PLA) derived from fermented plants like corn and sugarcane, which are environmentally friendly and harmless [1] Group 2 - The development team faced challenges in maintaining the required gas impermeability, tensile strength, and elongation while using new biodegradable materials [2] - After extensive testing, the team successfully achieved a high degradation rate while ensuring excellent physical properties of the balloons [2] - The balloons can start to decompose within a month under normal sunlight conditions, with a degradation rate of 60%-70% within 180 days, and complete degradation within 1 to 1.5 years, resulting in water, carbon dioxide, and organic matter [2]

Group 1 - The event commemorating the 80th anniversary of the victory in the Chinese People's War of Resistance against Japanese Aggression and the World Anti-Fascist War featured the release of 80,000 balloons, which raised concerns about their environmental impact [1][3] - The balloons used in the event are made from fully biodegradable materials, including natural latex, plant starch, and polylactic acid (PLA) derived from fermented plants like corn and sugarcane, distinguishing them from conventional balloons [1][2] - The special natural latex material used for the balloons is non-toxic, harmless, and has sustainable and degradable properties, marking a significant advancement in balloon manufacturing [1][2] Group 2 - The research team faced challenges in maintaining the required airtightness, tensile strength, and elongation of the balloons while using new biodegradable materials, which initially posed a conflict with the materials' degradability [2] - The balloons have a degradation rate of 60%-70% within 180 days under normal sunlight conditions, and they can completely decompose within 1 to 1.5 years, breaking down into water, carbon dioxide, and organic matter without causing permanent pollution [2] - Scientists are also exploring the development of bio-based composite materials that do not use aluminum foil, aiming to achieve gas barrier properties similar to natural latex [4]